Birds in Western Australian wheatbelt reserves—implications for conservation

Biological Conservation 22 (1982) 127-163

BIRDS IN WESTERN AUSTRALIAN WHEATBELT RESERVES--IMPLICATIONS FOR CONSERVATION D. J. KITCHENER, J. DELL, B. G. MUIR

Biological Survey Unit, Western Australian Museum, Francis Street, Perth, Western Australia, 6000 & M. PALMER

CSIRO Division of Mathematics and Statistics, Wembley, Western Australia, 6014

ABSTRACT Bird species richness in 22 reserves in the Western Australian wheatbelt was shown to be related not to isolation J?om adjacent uncleared land, either spatially or with time since clearing o f land in their vicinity, but to area o f reserve and certain reserve habitat variables. The nature of these relationships was examined with multiple regression analysis. Reserve area was the most important variable, except in some passerine groups, where numbers o f plant species, vegetation associations, and plant life f o r m and density classes in each vegetation stratum were, separately, more important than area. Eighty-two percent o f the variation in the number o f bird species was explained by area o f reserve and number o f plant species, indicating the importance of floristics to the total bird assemblage within reserves. The number of ]brmations present (the broadest vegetation structural grouping used) did not explain an), o f the variation in species numbers in an), o f the bird groupings. There were more resident passerine speciespresent in wheatbelt reserves than there were breeding passerine species on similar-sized southwestern Australian latePleistocene/Holocene islands, although the species versus area relationship o f the residem habitat-specific passerines (P5 group) was very similar to that o f the island land-bird jktunas. The P5 species group contained many species which probably responded to wheatbelt reserves as islands, some o f these species may fail to persist m the wheatbelt in the long term. Twenty-three species usually resident in reserves and 15 'non-residents' were identified as being 'vulnerable' or of uncertain conservation status in the wheatbelt. Some vegetation formations within reserves were more important to birds than others, woodlands were most important both to resident and transient species. Most ,species do not appear to distinguish between shrublands and heaths as major habitats. Species richness versus formation area relationships suggest that insular patchiness 127 Biol. Conserv. 0006-3207/82/0022-0127/$02-75 ~ Applied Science Publishers Ltd, England, 1982 Printed in Great Britain

128

D. J. KITCHENER, J. DELL, B. G. MUIR, M. PALMER

f o r birds in the wheatbelt was manifest at the level of vegetation formations. Reserves as small as 80ha were important sanctuaries f o r birds in the wheatbelt, although 1500ha was considered a minimum area o f reserve to conserve a local avifauna. Reserves o f the order o f 30,000-94,000 ha were required to contain most of the avifauna o f the wheatbelt. INTRODUCTION

The southwest of Western Australia has an intermingling of distinct avifaunas corresponding to the Eyrean and Bassian subregions (Serventy & Whittell, 1976). The wheatbelt, located between the humid southwest (Bassian) and the arid interior (Eyrean), has species from both subregions. Prior to our survey, knowledge of the wheatbelt avifauna was derived from scattered bird lists, especially Milligan (1904); Crossman (1909); Orton & Sandland (1913); Carter (1923); Sandland & Orton (1923); Sedgwick (1949); Ford & Stone (1957); Serventy (1958); Masters & Milhinch (1974); Dell (1976); and de Rebeira & de Rebeira (1977). Studies on migratory patterns and elucidation of residency status of wheatbelt avifauna has been largely ignored by previous studies. Serventy & Whitteil (1976) indicated that much bird migration in Western Australia was quite different from the classical migration pattern of the northern hemisphere; instead some species have regular but local partial migrations, others are irregular nomads responding to flowering seasons of food plants or the incidence of drought and good rains. They pointed out how exceptional seasons may encourage quite large irruptions of some species. Serventy & Marshall (1957), Serventy & Whittell (1976) and Davies (1979) report that most breeding in southwestern Australia occurs from July to December, although large-scale unseasonal breeding may occur after exceptionally heavy summer rains (Serventy & Marshall, 1957). The long-term persistence of much of the avif~/una of the Western Australian wheatbelt depends on about 500 haphazardly located nature reserves occupying only 2"4~o of the total wheatbelt area of 14 million ha. Between 1971 and 1979 we surveyed the avifauna and vegetation of 22 nature reserves and three other areas marginal to the wheatbelt (Fig. 1). The objectives of the project (in Kitchener, 1976) were first to provide annotated lists of vertebrate and plant species within these reserves (Chapman et al., 1977, 1978, 1980, 1981; Dell et al., 1979a,b,c, in press; Kitchener etal., 1975, 1976, 1977, 1979; and Muir (1977a,b) and Muir etal., 1978, 1980); and secondly to conclude information on zoogeography and conservation from these baseline data. The adequacy of the reserve system to conserve the vertebrate fauna was to receive particular attention; this has already been done for reptiles (Kitchener et al., 1980a) and mammals (Kitchener et al., 1980b). We assess the nature reserve system for the conservation of birds in the Western Australian wheatbelt by reporting on the status of the avifauna in the wheatbelt, the effect on bird species richness of selected reserve variables including area of reserve

BIRD CONSERVATION IN AUSTRALIAN WHEATBELTS

129

Fig. 1. M a p of southwestern Australia showing distribution of the 22 reserves studied in the wheatbelt and the other areas surveyed for comparison with the wheatbelt. Reserves are coded 1 22 and m a y be identified from Table I. Other areas referred to are indicated. The wheatbelt is the cereal-producing area of the State shown on the 1970 Land Use M a p of Western Australia Department of Lands and Surveys, Perth, Western Australia. Two reserves were not considered in the detailed analyses; one (Tarin Rock Nature Reserve) because it was extensively burnt between our bird surveys, and the other ( N u g a d o n g Forest Reserve) because it was not adequately sampled in spring and autumn.

and others related to vegetation, the factors affecting number of reserves occupied by individual species, and parallels with the land-bird faunas of Western Australian islands. METHODS

Observations were carried out on 22 reserves with the aid of binoculars during both spring and autumn for a minimum period of 5 days, with several of the larger

130

D. J. KITCHENER, J. DELL, B. G. MUIR, M. PALMER

reserves surveyed for 10 days. All vegetation formations and most vegetation associations were visited on each reserve. In addition to spring and autumn surveys of wheatbelt reserves opportunistic trips were taken into the wheatbelt to record birds at other times of the year. Almost all bird sightings used in this paper were recorded by Dell; those by other observers were verified by him. When necessary specimens were collected; these were lodged in the Western Australian Museum. Bird names follow Storr & Johnstone (1979). Vegetation was chosen as the indicator of habitat variety available to birds in each reserve (Muir, 1977a). This comprises a matrix of canopy density classes against plant life forms which are divided into a series of height classes for all strata. The habitat variable 'total number of life forms and density classes (LFDs)' used here is the number of the above matrix categories present in a reserve. Each LFD is scored only once. Vegetation terminology generally follows Beadle & Costin (1952) and Polunin (1960). Detailed association descriptions are available for most bird observational records in the publications cited earlier. The following subgroupings of passerine and non-passerine species in the wheatbelt are used throughout: R:

P1 and NP~: P2 and N P2 : P3 a n d N P3 :

P4 and N P4: P5:

resident--non-migratory, local movement only in. wheatbelt; usually in reserves during both autumn and spring (and occasional surveys). total passerines and non-passerines recorded in reserves and their immediate adjoining land, both cleared and uncleared. total passerine and non-passerines recorded in reserves only, including those feeding over vegetation canopy of reserves. resident passerine and non-passerines recorded in reserves only, including those feeding over vegetation canopy of reserves. resident passerines and non-passerines recorded only in 'natural' vegetation in each reserve. resident passerines recorded only in 'natural' vegetation in the wheatbelt.

Birds in the last category may occasionally be recorded in disturbed country in the wheatbelt, but the allocation of birds to this or another category is based only on our own observations. 'Natural' vegetation is that which retains its overall physiognomic complexity. The species in the groupings listed show a trend towards restricted mobility and narrow habitat preference, with P5 the most restricted. Multiple regression was used to relate reserve variables and bird species richness, and to compare the appropriateness of the two models used to describe the distribution of species number. Resident bird species were grouped by Furthest Neighbour Cluster analysis according to the number of reserves they occupied and measures related to the number of recorded sightings and habitat specificity.

B I R D C O N S E R V A T I O N IN A U S T R A L I A N W H E A T B E L T S

131

Similarities between bird assemblages in different vegetation formations were compared using Sorenson's Quotient of Similarity index (Clifford & Stephenson, 1975). RESULTS

Species richness and reserve variables The passerine and non-passerine species recorded are listed in Appendix 1. The total number of passerine and non-passerine species recorded in and around reserves and in reserves only, and their subgroupings, along with the reserve variables, are presented in Table 1. The highest correlation for each bird group between species richness and those reserve variables related to area of reserve was, with one exception, with reserve area alone (Table 2). For this reason, species richness will be related to reserve area alone in the subsequent treatment of our data and not with adjacent uncleared land or uncleared land within 5, 10, and 15km of the reserves. The exception was the resident non-passerine NP4 group which was slightly, but not significantly, more highly correlated with the area of reserve plus adjacent uncleared land. Most of the species groups were most highly correlated with area (Table 2). The exceptions were the passerine PE and P3 groups. Multiple regression was used to explain more variation. With the P1 group, the number of passerine species in and around reserves was most influenced by reserve area (A)with the addition of number of plant species (P) explaining significantly more variation. The multiple regression equation is:

S = - 16-08 + 8.22 log A + 17-11 log P(R 2 = 79 ~o) This grouping contains many of the transient and more vagile bird species, such as honeyeaters. We conclude that the presence of these species was more influenced by reserve area and floristics than by vegetation structure. The number of resident and 'non-resident' species (P/) in reserves was most highly correlated with number of plant species but with the addition of reserve area explaining significantly more variation. There is, however, an alternative multiple regression equation which explains a similar amount of variation; this considers number of LFDs and reserve area. The equations for the alternatives are: S = - 2 3 " 8 8 + 22.38 l o g P + 4 - 9 4 1 o g A (R 2 = 81~o) and S = - 2 . 9 2 + 16.801og L F D s + 5.92 logA (R 2 = 77 ~o). We conclude that numbers of species in group P2 were greatly influenced by floristics within reserves but that area of reserve and fine-scaled vegetation structure were important.

I. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22.

East Yuna Bindoo Hill Wilroy Marchagee Buntine East Nugadong Nugadong Billyacatting Durokoppin East Yorkrakine Yorkrakine Rock Kodj Kodjin North Bungulla North Yoting Yoting Town Badjaling flora Badjaling water Bendering West Bendering Yornaning North Tarin Rock Dongolocking

Reserve

56 36 43 42 46 40 38 47 48 35 42 38 32 27 25 38 18 48 48 44 49 54

PI

41 31 36 36 40 34 32 39 45 32 36 34 27 23 22 36 14 43 44 38 39 50

P2

29 23 25 21 27 25 25 26 29 20 23 22 19 15 13 19 10 29 28 24 23 30

11 9 15 12 20 13 18 18 18 13 11 13 14 10 3 11 6 25 20 17 18 22

No. of passerine species P3 P4

11 7 8 5 10 10 9 9 10 7 5 6 6 3 0 2 1 13 10 10 12 15

P5

51 18 26 35 29 19 24 41 22 14 21 20 12 13 12 32 11 28 29 23 31 29

18 12 15 17 24 11 18 27 16 11 13 13 8 10 6 24 7 24 22 13 22 21

10 8 8 4 10 6 10 12 8 8 7 5 5 4 3 9 4 11 9 7 8 8

3 I 2 1 3 1 2 3 1 3 2 1 1 2 0 4 I 8 3 4 3 3

No. oJ non-passerine species NP2 NP3 NP4

NP1

1717 486 332 495 3147 772 400 2075 1030 81 158 204 104 34 38 272 41 5119 1602 247 1415 1061

Reserve area (ha)

1717 786 332 1000 3439 772 400 2285 1142 81 158 204 104 34 38 272 41 7808 1974 447 2545 1361

Reserve area +adjacent uncleared land (ha) 3115 2693 401 3244 1560 1897 1283 1863 657 76 253 1174 125 305 54 116 369 4878 2038 1136 4955 2722

7227 8648 2461 7845 4104 6285 2631 4107 2804 1658 779 3513 711 1505 1086 281 513 10556 9112 3890 12934 4416

20555 11570 5014 17071 8592 9778 7810 7889 4733 3746 1337 4964 2305 2513 2676 2375 2079 19133 17236 9744 26662 7151

Other umleared land within 5kin IOkm 15kin

27 13 29 26 44 23 13 27 39 22 14 19 23 7 14 17 8 54 45 26 18 41

Total no. of LFDs

7 2 4 5 5 3 4 5 5 4 3 4 3 3 6 4 3 6 5 4 3 6

No. of jormations

25 12 22 14 36 17 10 22 26 II 13 12 16 4 6 12 4 45 27 8 10 32

No. of associations

164 83 ll0 143 183 101 71 132 177 88 119 90 150 50 72 111 37 288 187 107 105 230

N o oJ plant specie~

TABLE 1 N U M B E R OF PASSERINE A N D N O N - P A S S E R I N E SPECIES A N D THEIR S U B G R O U P I N G S , RESERVE AREA, AREA OF RESERVE A N D A D J A C E N T U N C L E A R E D L A N D , AREA OF U N C L E A R E D L A N D W I T H I N 5, 10 A N D 15 km, A N D N U M B E R OF VEGETATION LIFE FORM A N D DENSITY CLASSES (LFDs), F O R M A T I O N S , ASSOCIATIONS A N D P L A N T SPECIES FOR EACH WHEATBELT RESERVE. DEFINITIONS OF THE BIRD SPECIES S U B G R O U P I N G S A N D RESERVE VARIABLES ARE PRESENTED IN THE M E T H O D S SECTION.

TABLE 2

21)

PI species group P2 species group P3 species group P4 species group P5 species group NP I species group N P2 species group NP3 species group N P~. species group P~ + NP~ P: + NP: Reserve area Reserve area & adjacent area Uncleared land (5 km; Uncleared land (10km) Uncleared hind (15kin) LED no. Formation n o Association no. Plant species n o

Degree of freedom

t~1 {ii} till) (Jr) Iv) tvit Ivii) Iviii) tlx) {x} (xi} (Xli) txiii} Ixiv) (x~) (x',~) /xvii) (x,,iii} (XlX) (xx)

1'000 0.957 0.931 0723 0850 0,790 0.739 0.692 0480 0.942 0.922 0.858 -0852 0.662 0.646 0662 0770 0.500 0802 0822 01

1.000 0"927 0784 0 822 0'662 0748 0'662 0500 0850 0-953 0"824 0820 0574 0-571 0.565 0 830 0 506 0830 0.866 (iit 1.000 0.794 0.894 0626 0.667 0.741 0,448 0817 0.872 0.871 0848 0657 0.656 0.618 0800 0424 0 872 0813 liii) 1000 0.852 0,392 0723 0678 0.653 0.583 0810 0767 0.764 0.576 0528 0524 0.763 0357 0732 0733 (iv) 1,000 0.494 0.578 0 648 0505 0704 0.766 0813 0.813 0.728 0.735 0703 0-726 0322 0.732 0704 (v) 1.000 0776 0.645 0.410 0-950 0759 0732 0,721 0.594 0.470 0623 0490 0.558 0-566 0558 (vi) 1.000 0.814 0.642 0.802 0,914 0830 0'816 0.564 0.416 0.540 0596 0'452 0.662 0,640 (vii) 1.000 0'656 0'706 0.776 0.774 0730 0'438 0.364 0,455 0-544 0.325 0.674 0.552 (viii) IO00 0469 0'598 0.537 0546 0334 0.266 0.382 0.484 0357 0454 0526 (ix) 1000 0886 0'838 0'829 0-662 0"586 0'678 0.661 0'560 0718 0724 (x) 1.000 0.883 0,874 0-608 0'540 0.592 0.780 0"516 0.810 0822 (xi)

1"000 0"990 0.791 0.724 0.769 0-776 0"422 0849 0,784 (xii)

1-000 0"830 0.770 0'818 0.764 0-391 0.808 0.775 (xiii)

1.000 0.872 0.866 0-429 0"161 0.483 0.442 (xiv)

1.000 0'930 0'514 0.217 0'487 0.462 (xv)

I.O00 0.526 0"299 0-475 0.474 (xvi)

1-000 0-630 0'911 0'922 (xvii)

1.000 0.519 1-000 0.577 0-925 (xviii) (xix)

1,000 (xx)

MATRIX SHOWING CORRELATIONS BETWEEN (i) ( x i ) NUMBERS OF BIRD SPECIES IN THE PASSERINE ( P ) AND NON-PASSERINE ( N P ) GROUPS (SEE METHOD SECTION FOR DEFINITIONS OF THESE GROUPS) AND (xii) RESERVE AREA; (xiii) RESERVE PELTS ADJACENT AREA; ( x i v x v i ) AREA OF UNCLEARED LAND WITHIN 5, 10 AND 15 k m OF RESERVE; (xvii) YD. OF MUIR'S (1977a) VEGETATION LIFE FORM AND DENSITY CLASSES (LFDs); (xviii) NO. VEGETATION FORMATIONS; ( x i x ) NO. PLANT SPECIES. DEGREES OF FREEDOM = 2 0 . ALL VARIABLES ARE loglo TRANSFORMED.

134

D. J. K I T C H E N E R , J. D E L L , B. G . M U I R , M. P A L M E R

The number of resident species (P3) in reserves was best correlated with number of vegetation associations (V) but with the addition of reserve area explaining significantly more of the variation. An alternate equation which explains a similar amount of variation considers number of plant species and reserve area. The equations for the alternatives are: S = 2.30 + 8.851og V + 3.971ogA (R 2

82 "/~

and S = 0 . 8 1 + 8 . 5 7 1 o g P + 5 . 1 3 1 o g A ( R e=80~o). We conclude that total number of resident passerines were greatly influenced by both floristics and a combination of floristics and 'coarse' vegetation structure (associations) and to a lesser degree by area of reserve. The number of resident passerine species occurring only in natural vegetation in reserves (P4) was most highly correlated with area of reserve and with number of LFDs. The alternative equations are: S = - 8 . 5 9 + 17.16log LFDs (R e = 58 o/) and S = - 2 . 4 0 + 6-431ogA (R 2 = 590o). Species in this group appeared to be influenced by "fine' vegetation structure and reserve area, suggesting that these resident species were greatly influenced by vegetation stratification. The number of resident passerine species occurring only in natural vegetation in the wheatbelt (Ps) was most highly correlated with reserve area alone. The equation / is S = - 5 . 4 9 + 5.041og A ( R 2 = 66 o,/o). Most P5 species had very specific habitat requirements. It follows, then, because of the extreme patchiness of wheatbelt vegetation, that the probability of a P5 species being present in a reserve would depend largely on the area sampled by the reserve. For this reason we think that numbers of P5 species were statistically determined by area alone because area is a reflection of presence, or absence, of their required habitat and not that other habitat variables were not additionally important to area. Comparison of the relationships between all reserve habitat variables and reserve area for the nine reserves larger than 600 ha and the 13 reserves smaller than 600 ha (Table 3) shows that while there was a significant correlation between area and most habitat variables in the larger group of reserves this was not the case for those reserves smaller than 600 ha. This is evidence that smaller reserves inadequately sample habitat diversity. Numbers of non-passerines species in each of these groups N P 1, N P z, N P 3 and N P 4 were most highly correlated with reserve area alone. The equations representing these relationships, followed in brackets by the percentage of the variation they explain, are as follows: SNp' = --5"83 + 11-621ogA

( R 2 ~-

54~o)

BIRD CONSERVATION IN AUSTRALIAN WHEATBELTS

+ 8'09 log A ( R 2

=

69

135

~o)

SNp 2 =

-- 5" 15

SNp 3 =

-0"51 + 3"05 I o g A ( R 2 = 60 ~o)

SNp, = -- 1-37 + 1"43 log A (R 2 = 29 ~o) Reserve variables additional to area do not account for significantly more variation in numbers of non-passerine species between reserves. Nevertheless, there were significant correlations with all other reserve variables. This is explainable for the N P~ group, which was dominated by transient waterbird, parrot, and raptorial species which feed and utilise extensively areas around nature reserves. Thus the ecology of the reserves may not be the most important factor determining their presence or absence within and around a reserve. With the resident non-passerine groups (NP2, N P 3 and NP4), the arguments presented above for the P5 group that reserve area is the principal factor determining presence or absence of their required habitat probably also apply here. TABLE 3 CORRELATION COEFFICIENTS ( r ) BETWEEN RESERVE AREA AND MEASURES OF VEGETATION VARIETY (NUMBERS OF LFDs, FORMATIONS, ASSOCIATIONS AND p L A N T SPECIES) FOR RESERVES LARGER AND SMALLER THAN 600ha, N = NUMBER OF RESERVES. SIX H U N D R E D HECTARES WAS SELECTED AS THE C U T - O F F FIGURE BECAUSE THE MOST HABITAT-SPECIFIC RESIDENT PASSERINE G R O U P ( P 5 ) DECLINED IN RESERVES LESS THAN A B O U T 6 0 0 ha, SUGGESTING T H A T RESERVES SMALLER THAN THIS SIZE MAY FAIL TO I N ( ' L U I ) E REPRESt-NTATIVES OF BASIC WHEA'IBELT HABITAT TYPES.

Vegetation variety

r values Reserves < 600 ha N=13

No. No. No. No.

LFDs formations associations plant species

0.36 - 0.04 0.49 0.37

Reserves > 600 ha N=9

0.63* 0.36 0-76* 0.67*

* Significant at 5 °6,.

Total number of bird species in and around reserves (P~ + N P1) was most highly correlated with reserve area. The equation is S = 1,61 + 24.31 logA ( R 2 = 7 0 /oo/) . The influence of habitat variables on species richness of most of the passerine species was probably overridden by the effect reserve area alone had on the more transient bird species and on those that extensively utilise areas outside reserves. The total number of bird species in reserves (P2 + NP2) was most highly correlated with reserve area, although the addition of number of plant species in reserves explained significantly more variation. The equation is S = - 2 7 . 9 4 + 13.23 logA + 21.59 log P (R 2 = 82 ~o). We conclude that floristics within reserves are very important to bird assemblages largely confined to reserves.

136

D. J, KITCHENER, J. DELL, B. G. MUIR, M. PALMER

Species richness regressed on reserve area C o n n e r & McCoy (1979) have shown the need to establish the e q u a t i o n of best fit when e x a m i n i n g the relationship between a n i m a l species richness a n d area. The e q u a t i o n of best fit relating bird species richness to wheatbelt reserve area is generally S v log A, a l t h o u g h the correlations achieved with log S v log A are similar (Table 4). The correlation coefficients (r) a n d c o n s t a n t s C a n d z shown in Table 4 refer to the log S v l o g A t r a n s f o r m a t i o n s , because these are the c o n s t a n t s most frequently considered in the literature ( C o n n e r & McCoy, 1979).

TABLE 4 R E L A T I O N S H I P BETWEEN (a) logS v logA A N D (b) S v logA, ESTIMATES OF PARAMETERS 2 A N D C , A N D C O R R E L A T I O N COEFFICIENTS ( r ) FOR BIRD SPECIES IN W H E A T B E L T RESERVES A N D THEIR IMMEDIATE V I C I N I T Y . SPECIES ARE G R O U P E D BY H A B I T A T A N D RESIDENCY AS D E F I N E D 1N METHODS. T H E R E L A T I O N S H I P S F O R B R E E D I N G PASSERINE SPECIES FROM 1 4 S O U T H W E S T E R N A U S T R A L I A N I S L A N D S W I T H I N THE SIZE R A N G E OF THE ABOVE W H E A T B E L T RESERVES ARE ALSO PRESENTED FROM D A T A IN A B B O T T (1978).

Habitat and residency category

z

(a) Total birds in vicinity (P~ + NP 0 Total birds in reserves (P2 + NP2) Total passerines (P2) Resident passerines (P3) Resident passerines, natural vegetation (PJ Resident passerines, natural vegetation (Ps) Breeding passerines, SW islands Total non-passerines (NP2) Resident non-passerines (N P3)

0.182 0.183 0.155 0.160 0.235 0.346 0.482 0.247 0.200

(b) Total birds in vicinity (Pl + NP1) Total birds in reserves (P2 + NP2) Total passerines (P2) Resident passerines (P3) Resident passerines, natural vegetation ( P 4 ) "Resident passerines, natural vegetation (Ps) Breeding passerines, SW islands Total non-passerines (NPz) Resident non-passerines (NP3)

24310 18.870 10.782 7-372 6-429 4.666 3.831 8.088 3-046

c

r

N

1-319 1.213 1.125 0.927 0.508 -0-081 -0.680 0.524 0.323

0.853 0-859 0.799 0-841 0.726 0.731 0-709 0.845 0.767

22 22 22 22 22 21 14 22 22

1.610 1.745 6.895 3.677 -2.402 -4.385 -4.726 -5.150 -0.511

0.838 0-882 0.825 0.871 0.767 0.780 0.669 0.830 0.774

22 22 22 22 22 21 14 22 22

Yoting Town Reserve had no P5 species: to enable comparison with the same data set used in the log S v log A transformation, this reserve was also excluded from the S v log A transformation in this table (but is included in the multiple repression analysis). Passerine and non-pas,wrine species considered together. The total n u m b e r of passerine and n o n - p a s s e r i n e species in reserves ( P2 + N P2) increased m a r k e d l y from smaller reserves to those of a b o u t 1500 ha, after which there appeared to be little increase, with the bird assernbhlge at a b o u t 65 species (Fig. 2). The correlation coefficient of 0-86 between l o g ( P 2 + N P 2) a n d log area is higher than that achieved by any of the s u b g r o u p s of passerine a n d n o n - p a s s e r i n e species listed in Table 4. This correlation is not e n h a n c e d by considering area of uncleared land adjacent to, or within 5, 10, a n d 15 km of, each reserve. The _ value of 0.18 is that expected for a n o n - i n s u l a r situation ( M a c A r t h u r & Wilson, 1967).

137

BIRD C O N S E R V A T I O N IN A U S T R A L I A N W H E A T B E L T S

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Fig. 2. T h e r e l a t i o n s h i p b e t w e e n t h e a r e a o f reserves a n d (a) the total n u m b e r o f bird species in reserves (P2 + N P 2 ) a n d n u m b e r s o f the p a s s e r i n e species in the P2, P3, P4 a n d P5 s u b g r o u p i n g s ; a n d (b) the species in the N P 2 a n d N P 3 n o n - p a s s e r i n e g r o u p i n g s . See M e t h o d s for e x p l a n a t i o n o f bird species s u b g r o u p i n g s . Lines fitted f r o m e q u a t i o n s o f best fit ( T a b l e 4).

The correlation coefficient of 0.85 between log total species in and around reserves (P1 + NP1) and log reserve area is similar to the comparable value for P2 + NP2 and as above is not enhanced by consideration of the surrounding uncleared land. The z value (0.18) is similar to that for P2 + NP2. Passerine species." The species versus area relationships for all passerine birds in reserves (P2) were similar to those of the total bird species (Fig. 2). Most of the resident and/or 'non-resident' passerine bird assemblage in a given locality were

138

D. J. K I T C H E N E R , J. D E L L , B. G . M U I R , M. P A L M E R

found in'reserves larger than 1000-1400 ha; most of 20 species in the very habitatspecific group of resident passerines (Ps) were present in reserves larger than 600-800 ha. As with our other groupings of birds the highly significant correlations between numbers of passerine species (P2, P3, P4 and Ps) and reserve area (p < 0-001) are not enhanced by considering area of land adjacent to, or within 5, 10 and 15 km of, each reserve. The z value increases with increasing residency and habitat specificity in reserves such that the Pz and P5 groups have z values of 0.16 and 0-35 respectively. Both the habitat specific (P4 and Ps) passerine groups have z values expected from isolated or island faunas (MacArthur & Wilson, 1967). Non-passerine species: The species versus area regressions for non-passerines (Fig. 2b) were also similar to those of the total bird species; most of the local nonpasserine assemblage (NP 2) were present on reserves larger than about 1600ha compared with about 1000ha for resident non-passerines (NP3). It is apparent numerically that non-passerine species were not as important an element as the passerines in wheatbelt reserves; also there were fewer non-passerine species reliant on natural vegetation and resident in reserves (N P4) and none at all comparable with the P5 group, which in the wheatbelt was restricted to natural vegetation. The z values for both the N P 2 and N P 3 species of 0.25 and 0.20, respectively, is higher than all passerine categories except the P5 group. This is explained, however, by the fact that most of the N P 2 group are water birds, and require aquatic habitats, generally absent from small reserves. Relationship between passerines and the total bird assemblage (P2 + NP2): The proportion of passerine species to total bird assemblage in reserves was correlated with log reserve area in two cases: Pz ( r = -0-51, p < 0.05), and P5 (r = 0"61, p < 0.01). The proportion of passerine species to total bird assemblages in reserves tended to change with area of reserve (Fig. 3). On smaller reserves there was a larger proportion of total passerines (P2). This trend was reversed for the most habitatspecific group of resident passerines (Ps). There appeared to be no trend indicating change in proportion of the P3 or P4 resident passerine group with area of reserve. These observations suggest that below about 600-800 ha for the P5 species and above about 1000 ha for Pz species some factors operate selectively to disadvantage the P5 species relative to other species groupings. Possibly an important factor is their habitat specificity; they were only recorded in natural vegetation, so that it may be that the greater depletion of major vegetation elements on smaller reserves relative to larger ones may result in fewer Ps species surviving in smaller reserves.

Species richness and vegetation Jormations Total resident and non-resident species: Many more species of the total bird assemblage in reserves (P2 + NP2) were recorded in woodlands, including treemallees (100 species) than in other major formations (22.-76 species), with few

BIRD CONSERVATION

IN AUSTRALIAN

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species recorded in breakaway, salt complex and remaining formations (3-14 species) (Table 5). Woodlands also had a higher number of non-resident species (53), compared with shrub-malice (34), shrubland (37), heath (26), lithic complex (13), breakaway (1), salt complex (10) and remaining formations (8). Woodlands were the most important habitat for birds in the wheatbelt; they contained more absolute numbers of species, more numbers of species per hectare and had more species restricted to them (Table 5). Further they had more 'non-resident' species and as such are likely to be most important for the movement of birds throughout the TABLE 5 NUMBERS OF TOTAL BIRD SPECIES (P2 + NP2), RESIDENT BIRD SPECIES (P3 + N P 3 ) , AND HABITAT-SPECIFIC RESIDENT PASSERINE SPECIES (P5) IN EACH VEGETATION FORMATION 1N WHEATBELT RESERVES, NUMBER OF SPECIES PER 1000ha, AND NUMBER OF SPECIES RESTRICTED TO EACH FORMATION. OCCASIONS WHEN A SPECIES IS OBSERVED LESS THAN 5 ~ooOF ITS TOTAL SIGHTINGS IN A GIVEN FORMATION ARE NOT INCORPORATED INTO THIS TABLE. Formation type

Formation area

Number of species

P2 + NP2 P~ + NP3

Woodland

2381

100

Malice

5835 3519 2959 1960 107 33 3986

76 78 56 22 3 14 13

Shrubland Heath Lithic c o m p l e x Breakaway Salt c o m p l e x Others

47 42 41 30 9 2 4 5

Number of spp/lOOOha

Ps 15 15 15 14 3 1 1 1

P2 + NP2 P~ + NP~ 42"0 13"0 22.2 18.9 11-2 28"0 424.2 3.3

19.7 7.2 11.7 10.1 4.6 18.7 121.2 1.3

Ps 6-3 2.6 4.3 4.7 1-S 9.3 30.0 0.3

Number of restrictedspecies

P2 + NP2 P3 + NPa 12 0 0 2 0 1 12 2

3 0 0 0 0 1 0 0

Ps 3 0 0 0 0 0 0 0

140

D. J. KITCHENER, J. DELL, B. G. MUIR, M. PALMER

wheatbelt. These results concur with those of Willson (1974), who observed that addition of trees greatly increases numbers of bird species when compared with structurally less complex situations; she concludes that this increase 'may not be due to an increase in productivity of resources, but rather of environmental patchiness in three dimensions, leading to new possibilities of differential space exploitation'. A similar assemblage of P2 + NP2 species inhabited woodlands, shrub-mallee and shrubland with quotient of similarity between pairs of these formations ranging between 0.70-0.79 (Table 6). There was a significant correlation between numbers of P2 + NP2 species and area of woodland, shrub-mallee, shrubland and heath, but not for lithic complex (Table 7). The equation of best fit varies slightly for these formations between log S v tog A (shrubland, heath) and S v log A (woodland and shrub-mallee). Because heaths and shrublands were similar fioristically and may vary only in age (hence height) of plants, data from these two formations were grouped. When this is done a higher correlation was achieved than when these formations were treated separately, with log S v log A the equation of best fit. Whereas shrublands and heaths had a resident passerine P5 assemblage more similar to each other than to any other pairing of formations (Table 6). This was not the case with the total species group (P2 + NP2), although with this latter species group again the assemblage in heaths was more similar to that in shrublands than to other formations. We did not think it appropriate to group data from other vegetation formations in a similar way, first because they differed greatly in floristics and vegetational physiognomy, and secondly because they were utilised by bird species in different ways. The relationships for the P2 + NP2 group between log S v logA were significant for all formations except lithic complex. Using this relationship the z values for woodland, shrub-mallee, shrubland and heath are 0.22, 0.21, 0.26, 0-20 and 0.33, respectively. These are all values indicative of vegetation formations being used as 'islands' by the total P2 + NP2 group. Passerine resident habitat specific group (Ps): Approximately equal numbers of P5 species (14-15) occurred in the major formation types, with few species (1-3) recorded in lithic complex, breakaway, salt complex and other formation types (Table 5). Only woodland has P5 species apparently restricted to it. The three restricted species (Acanthiza inornata, Climacteris rufa and Falcunculus frontatus) were uncommon in the wheatbelt (each recorded from only two reserves) while the other 17 P5 species were recorded, on average, from 10 reserves (range 2-21). Woodlands contain more P5 species per hectare than the other major formations. A similar assemblage of P5 species inhabits shrub-mallee, shrubland and heaths with quotient of similarity between pairs of these formations ranging from 0"83-O'89 (Table 6). There were significant correlations between numbers of Ps species and area of

141

BIRD CONSERVATION IN AUSTRALIAN WHEATBELTS TABLE 6

SIMILARITY INDICES FOR ASSEMBLAGES OF ALL PASSERINE AND NON-PASSERINE SPECIES (P2 q" N P 2 ) AND HABITAT-SPECIFIC RESIDENT PASSERINE SPECIES ( P s ) IN DIFFERENT FORMATIONS IN WHEATBELT RESERVES. QUOTIENTS OF SIMILARITY CALCULATED ~A,'ITHSORENSEN'S (1948) FORMULA (Clifford & Stephenson, 1975). OCCASIONS WHEN A SPECIES IS OBSERVED LESS THAN 5 ~o OF ITS TOTAL SIGHTINGS IN A GIVEN FORMATION ARE NOT INCORPORATED INTO THIS TABLE. Ps VALUES ARE BRACKETED. Vegetation ]ormation

M

Woodland Mallee (M) Shrubland (S) Heath (H) Lithic complex (L) Breakaway (B) Salt complex (Sa)

S

0-77(0-67)

H

0-70(0.53) 0-79(0.87)

L

054(0.48) 0-62(0.83) 067 (0.90)

B

0.31(0.11) 0.37(0.33) 0.38 (0.33) 0.33(0.35)

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0-21(0) 0.24(0) 0-28 (0) 0.29(0) 0-22(0) 0-12 (0)

Others

0.14(0) 0.11 (0.13) 0.11 (0.13) 0.14(0.13) 0.06(0.50) 0 (0) 0 1510)

TABLE 7 RELATIONSHIP BETWEEN (a) S v A, (b) logS v logA, (c) S v logA AND (d) logS v A, ESTIMATESOF THE PARAMETERS (Z AND C) AND CORRELATION COEFFICIENTS (r) FOR THE TOTAL NUMBER OF BIRD SPECIES IN RESERVES (P2 + N P2) AND FOR THE GROUP OF RESIDENT PASSERINE SPECIES ( P s ) - - A N D AREA OF VEGETATION FORMATIONS IN THE WESTERN AUSTRALIAN WHEATBELT.

Vegetation formation

~ P2 + NP2

P5

C P2 + NP2

P~

P2 + NP2

i P5

N P2 + NP2

P~

(a) W M S H L S+ H

0.060 0.005 0.017 0-013 0.013 0.011

0.011 0.002 0-005 0.002 0.004 0.005

28.590 23-527 16.562 t 1-549 10.224 20-566

2.305 0.496 4.256 3.889 1.486 6.932

0748 0.501 0.571 0.492 0.614 0-516

0750 0.723 0.777 0.279 0-869 0-672

17 15 20 20 7 22

16 15 18 16 6 19

(b) W M S H L S+ H

0-218 0-211 0.263 0.198 0.205 0-331

0.296 0.304 0-206 0.194 0.180 0.323

0.799 0.660 0.756 0.578 0.381 0-820

0.674 0.7116 0.780 0-417 0.430 0.748

17 15 20 20 7 22

16 15 18 16 6 19

(c) W M S H L S+ H

15.715 10.703 10-012 4.847 6.929 12.699

2.266 0.807 2.393 1.101 1.605 5.484

8-766 4.361 1.959 5.105 0.493 -2.894

-0-234 -1.531 0-803 2.059 -0.368 -3.722

0.8011 0.703 0.738 0.544 0.538 0.795

0.651 0.807 0.788 0.311 0.582 0.795

17 15 20 20 7 22

16 15 18 16 6 19

(d) W M S H L S+ H

0.001 0-000 0.000 0.000 0.000 0.000

0.000 0.000 0-000 0-000 0.000 0.000

1.433 1.321 1.138 1.008 0.881 1.233

0.334 0.581 0.605 0-522 0.154 0.787

0.647 0.409 0.520 0-437 0.496 0.449

0.133 0.499 0.653 0.315 0.705 0.557

17 15 20 20 7 22

16 15 18 16 6 19

1-140 -0-040 0-936 0.035 0.741 I 0.289 0-730 0-188 0.608 -0-040 0.605 0-144

W, woodland; M, mallee; S, shrubland; H, heath; L, lithic complex. Correlation coefficients are in bold if significant at 5 %.

142

D. J. K I T C H E N E R , J. D E L L , B. G . M U I R , M. P A L M E R

woodland, mallee, shrubland and lithic complex, but not for heath (Table 7). The equation of best fit varied for these formations between S v A (woodland and lithic complex) and S v log A (shrub-mallee and shrublands). The absence of a correlation with heath is surprising because 14 of the 20 P5 species utilise heaths. Most of the P5 species which utilise heaths were also frequently recorded in shrublands. Grouping data for shrublands and heaths gave a significant correlation (r = 0.80) with S v log A as the equation of best fit. The relationships for the P5 group between logS v logA were significant for woodlands, shrub-mallee, shrubland, and shrubland +heath. Using this relationship the z values for these formations are 0.30, 0.30, 0.21 and 0.32, respectively. These formations act more as vegetation 'islands' for the P5 group than they do for the P2 + N P2 group with the exception of shrublands + heaths which have similar : values to the latter group.

Factors influencing the number oJ wheatbelt reserves occupied by bird species Trophic level, degree of habitat specialisation and body size greatly affect the probability of a species occurring on islands (Brown, 1971). Measures of these factors (feeding type, body weight, and number of vegetation LFDs utilised by a species) were compared with the number of reserves occupied by each species. Data for these comparisons are in Appendix I. Passerine species." There was a very high correlation (p <~0.001) between the number of reserves occupied by the passerine species groups (e.g., P2, P3 and Ps) and the number of LFDs in which they were recorded (r =0-91, 0.93 and 0.97, respectively). Figure 4, which graphs these relationships, also indicates the feeding category of passerine species. It shows that feeding-type of species did not greatly influence the number of reserves on which they occurred, except for nectarivores which tended to utilise relatively fewer habitat types and to occupy fewer reserves than other bird feeding-types. This suggests that the 10 nectarivorous passerine species (honeyeaters) were relatively selective about the plants they fed from (at least in a temporal sense). Halse (1977) found this to be the case with six species of honeyeaters studied in East Pingelly Nature Reserve in the southern wheatbelt. He considered that during spring 1976 one species of plant, Dryandra sessilis, was their major source of nectar. The brown honeyeater Lichmera indistincta appeared to be exceptional in that it occupied 29 LFDs and was found on 20 reserves. Four of the nine passerine species with a restricted distribution in the wheatbelt are the honeyeaters Meliphaga cratitia, Phylidonyris novaehollandiae, Acanthorhynchus superciliosus and Anthochaera chrysoptera. The others are Petroica multicolor, Myiagra inquieta, Acanthiza inornata, Malurus lamberti and Artamus minor. It may be that restricted climatic tolerances or inability to compete with birds with similar ecologies, rather than habitat, restricted some of these species within the wheatbelt and reduced the number of reserves on which they occurred. Competitive exclusion probably

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Fig. 4. R e l a t i o n s h i p between the n u m b e r o f Western A u s t r a l i a n w h e a t b e l t reserves occupied, and a m e a s u r e o f the h a b i t a t specificity ( L F D s : see M e t h o d s for e x p l a n a t i o n ) for (a) passerine and (b) nonpasserine species. Species resident in reserves are the s h a d e d s y m b o l s : the habitat-specific resident passerine Ps g r o u p of species is indicated by the n u m b e r '5'. The p r i m a r y feeding c a t e g o r y of each species is also s h o w n as follows: IS], i n v e r t e b r a t e feeder; ~3, o m n i v o r e ; A , nectarivore; ~7, g r a n i v o r e ; 0 , c a r n i v o r e ; O , herbivore.

144

D. J. KITCHENER, J. DELL, B. G. MUIR, M. PALMER

applies to several ecologically vicarious passerine species, namely Petroica multicolor/P, goodenovii, Acanthiza inornata/A, uropygialis and Malurus lamberti/ M. pulcherrimus. However, omitting these from the above analysis does not greatly alter the correlation between number of reserves occupied by a species and number of L F D s it used (P2: r =0.887; P3: r =0-911, and Ps: r =0.972). Body weight of the P2, P3 and P5 species was not significantly correlated with number of reserves they occupied; these correlations were not significantly enhanced by leaving out the species considered to have restricted distributions in the wheatbelt. Non-passerine species (excluding water birds): The non-passerine N P 2 and N P 3 species show a strong correlation (p < 0-001) between the number of reserves they occupied and the number of L F D s in which they were recorded (r = 0"89 and 0"83 respectively). Figure 4 indicates that, of the feeding types, only carnivores appeared to be limited in that they tended to utilise fewer habitat types and to occupy fewer reserves. Body weight of the N P 2 and N P 3 species were not significantly correlated with number of reserves they occupied.

Comparison between passerine faunas in wheatbelt reserves and southwestern Australian continental islands The distribution of habitats on continents forms patchworks; accessibility to fauna of each habitat patch or 'island' is usually obscure and depends on nature and extent of surrounding habitat and effects of climatic history and man on the patches (Cody, 1975). The southwest of Western Australia is covered with a complex of 'habitat islands' such that Main (1979) attributes the reduced faunal complexity of the region to adaptation of its fauna to these 'habitat islands'. Wilson & Willis (1975) state that nature reserves are 'destined to become islands in a sea of habitats modified by man'. The extent to which wheatbelt reserves have become 'habitat islands' for birds can best be evaluated through direct comparison between their avifauna and that of those Western Australian islands containing a comparable avifauna. The passerine fauna of the wheatbelt included most of those species on South West islands. Comparison was, then, made between the S v log A relation of resident passerines in wheatbelt reserves with the comparable group from these islands. Abbott (1978) compared passerine species assemblages for 32 islands around the South West coast with those from similar habitat in adjacent mainland plots. He observed that island habitats had fewer passerine bird species than similar mainland habitats and concluded that this was because most passerine species are poor colonisers and not that competitive exclusion was more pronounced on islands than the mainland. Further he established that these island passerine assemblages are relatively stable, probably because immigration of species of land birds occurs infrequently, natural extinction is rare, and the degree of saturation of the avifaunas

145

BIRD CONSERVATION IN AUSTRALIAN WHEATBELTS

is low. These observations on South West islands supported earlier work on other Australian islands (Abbott, 1973). The island data are taken from Abbott (1978, Table 2) for those 14 islands that fall within the size range of wheatbelt reserves (32-5119ha). For these islands (Table 4) the correlation of log S v log A was higher than S v logA. Further, a possible complication to such a comparison is our different assessment of the resident category of birds from that of Abbott (1978), who based residency on whether or not a species bred on an island. Breeding of a species in a wheatbelt reserve does not necessarily imply that it is resident there throughout the year. However, because of the low rate of turnover of passerine species that Abbott (1978) postulates for these islands, his resident category for islands is thought to be similar to ours for wheatbelt reserves.

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BIRD CONSERVATION IN AUSTRALIAN WHEATBELTS

147

and our vegetation variables have components in common with the other vegetation measures cited, comparisons can be made with other studies. Our data tend to support those authors (Willson, 1974; Roth, 1976; Terborgh, 1977) who are sceptical about the value of some of the coarse structural measures, such as foliage height diversity (that have been almost universally applied), for predicting bird diversity within subcommunities of birds and/or of vegetation. For example, depending on the passerine species group being considered, measures of vegetation floristics (plant number), floristics and structure (associations) and finer measures of plant structure (LFDs) became additional to wheatbelt reserve area in determining species richness. Further, it is possible that studies such as those of MacArthur & MacArthur (1961), MacArthur etal. (1966), Recher (1969) and Roth (1976) may have over-emphasised the importance of vegetation structure, relative to floristics, in determining bird species richness because they carried out their bird census during the bird breeding season. During such times the structure of vegetation frequently assumes great importance to birds and greatly influences their short-term distribution through their particular requirements of nesting holes and other sites to build nests. Abbott (1978) observed that numbers of breeding passerine species on southwestern Australian islands were, in addition to area, also correlated with number of plant species but not with his measures of vegetation structure (comparable with our formations). Other detailed measures of vegetation structure used by him were also important in some situations. For example, number of breeding passerines was correlated with horizontal foliage diversity on islands, but not with the adjacent mainland and with vertical foliage diversity on both islands and mainland. Conservation status." Post-European changes in wheatbelt avifauna have been the introduction of a few exotic species; a southward incursion of some arid species notably Ocyphaps Iophotes, Cacatua roseicapilla and C. tenuirostris; increase in populations of some species including Playcercus zonarius, A nthus novaeseelandiae, A rtamus cinereus, Cracticus nigrogularis, C. tibicen and Corvus coronoides; and reductions in populations of many species, especially insectivorous passerines which feed among natural vegetation. Comparison of the wheatbelt avifauna with a very similar one in a 1200-ha area, situated in an extensive tract of natural vegetation near Lake Cronin, 100 km east of the wheatbelt, showed that the distribution of species in the various feeding categories was similar (Table 8). Water birds were excluded from this comparison because of the presence of Lake Cronin, a body of fresh water more extensive than is found within wheatbelt reserves. The proportion, then, of wheatbelt species in each of the feeding categories probably also approximates the situation prior to extensive clearing in the wheatbelt, although not necessarily in their original numbers. Although we are unable to demonstrate any notable losses of species from the wheatbelt avifauna, it is possible that species have been lost from individual reserves.

148

D. J° KITCHENER, J. DELL, B. G. MUIR, M. PALMER TABLE 8

PROPORTION OF PASSERINES (P) AND NON-PASSERINE (NP) SPECIES IN EACH OF THE PRIMARY FEEDING CATEGORIES~ FROM LAKE CRONIN AREA, WESTERN GOLDFIELDS, WESTERN AUSTRALIAAND FIVE WHEATBELT RESERVES LARGER THAN 1500 ha (RANGE OF VALUESGIVEN). N, NUMBER OF SPECIES. NON-PASSERINESPECIES FEEDING IN AQUATICSITUATIONS(10 AT L A K E CRONIN, 1-2 IN FIVEWHEATBELTRESERVES) ARE NOT INCLUDED IN THIS TABLE.

Feeding categories

Lake Cronin area P~ NP% 43 20

N Carnivores Nectarivores Granivores Invertebrate feeders Omnivores Frugivores

2.3 14.0 0 76-7 7.0 0

Five wheatbelt reserves

30-0 5-0 30.0 35.0 0 0

P%

NP%

39-44

18-27

2.3-5.1 4.9-11.6 0-2-3 66.7-75.0 9.3-17-9 0-2.6

23.8-33.0 4.5~,.8 30.0-36-4 22-2-28.6 9.1-11.1 0

Comparison of the avifauna on reserves isolated for the greatest period of time, namely those in country cleared about 1905 rather than those cleared about 1920 and 1950 (Kitchener 1980a) does not suggest that the 'older' reserves have a relatively depauperate avifauna. Species versus log Area relationships of the total birds in reserves (P2 + NP2) show that reserves in country cleared about 1905, 1920 and 1950 have slopes and intercepts that were not significantly different (Fig. 6). Similar comparison for the resident birds (P3 + NP3) showed the same trends. Thus we are unable to indicate any loss of species from the wheatbelt reserves . S = 6.0 + 18.7 log A (r = 0.75)

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Fig. 6. Relationship between the species richness in Western Australian wheatbelt reserves of the total passerine and non-passerine species in wheatbelt reserves, and reserve area for those reserves cleared circa 1905 (A), 1920 (11) and 1950 (O). Area is log transformed.

BIRD CONSERVATION IN AUSTRALIAN WHEATBELTS

149

during the period of land clearing in the wheatbelt (about 70 years), implying that loss of species from reserves will be a slow process. The total resident passerine species richness in wheatbelt reserves is much higher per unit area than on South West islands. This is probably a reflection of the generalisation by Abbott (1973, 1978) that passerine faunas on Australian (and New Zealand) continental islands are impoverished (undersaturated) relative to their comparable mainland areas. Abbott (1978) concludes that this is so because most passerine species are poor colonisers. It is probable, however, that passerine species will also be poor colonisers ofwheatbelt reserves as these reserves become more isolated through further land clearing and degradation of existing patches and corridors o f ' n a t u r a l ' vegetation, including road verges, outside reserves. Some support for this belief is provided by the sedentary nature of some South West passerine species as indicated by their tendency to form geographic variants (see Mayr & Serventy, 1938; Ford, 1970 & 1971). Thus loss of bird species from wheatbelt reserves appears inevitable without management. Despite this prediction it is most unlikely that the wheatbelt resident passerine species (Ps) versus area relationship will approach that of the South West islands, even in 10,000years. This is because we have recorded most P5 species in road verges, and corridors of vegetation passing throughout the wheatbelt, ensuring better immigration routes into wheatbelt reserves than are available into continental islands. Further, even if all 16 resident passerine species of'vulnerable' or 'uncertain' conservation status (later, this section) were to be lost from those wheatbelt reserves in which they occur, the equation of S -- 7.7 + 4.1 log A (r = 0-75) which would then describe the resident passerine species reserve area relationship would have a slope very similar to the comparable South West island relationship, but wheatbelt reserves would still, on average, contain from 12 13 more resident passerine species than the islands. Smaller reserves frequently lack broad habitat elements, such as entire vegetation formations (Table 3). The loss of these can be expected to affect residents most, particularly the more habitat-specific species--a fact that probably explains the proportionately lower number of P5 species relative to all other groups of birds considered (except the water birds) in small ( < 600 ha) wheatbelt reserves. Hence P5 species will be amongst the birds most affected by land clearing in the wheatbelt. Other evidence which supports this contention is provided by the 'island' nature of the species versus area relationship of the P5 group, demonstrated by its relatively high z value and by direct comparison with South West islands. On average, Ps species were recorded on 44.4 occasions in 8.5 reserves compared with 100.5 occasions and 16.0 reserves for other passerine species (these are not absolute numbers of sightings but number of occasions a species was recorded in a different vegetation association or in the same association but at a different season); these averages are little altered if those species with suspected restricted distribution are not included. Resident passerine and non-passerine species were grouped by the Farthest

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N e i g h b o u r Cluster Analysis. A d e n d r o g r a m showing these g r o u p i n g s (Fig. 7) was c o n s t r u c t e d f r o m the following species d a t a listed in A p p e n d i x I: n u m b e r o f reserves o c c u p i e d ; n u m b e r o f occasions r e c o r d e d as present in different vegetation associations, o r the same a s s o c i a t i o n but in different seasons; a n d n u m b e r o f L F D s occupied. T h e latter two variables are a m e a s u r e o f frequency o f o c c u r r e n c e in reserves and o f h a b i t a t specificity, respectively.

10-

20-

30-

40-

8, Cr-~

50-

60-

i~

70-

CO

GROUPS

Fig. 7. Dendrogram, produced by Furthest Neighbour Cluster Analysis, grouping resident passerine and non-passerine species on the basis of characteristics of species thought to reflect their conservation status. These were (1) number of reserves they occupied: (2) a measure of their abundance in reserves: and (3) a measure of their habitat specificity in reserves. The d e n d r o g r a m shows four m a j o r g r o u p s (A, B, C and D ) - - e a c h with two s u b g r o u p s (1 a n d 2). Species within each g r o u p are i n d i c a t e d by n u m b e r s which are identified in A p p e n d i x I. W e c o n s i d e r that those species with the m o s t ' v u l n e r a b l e ' c o n s e r v a t i o n status will be f o u n d in the group(s) c h a r a c t e r i s e d by species t h a t were f o u n d in few reserves, infrequently r e c o r d e d , a n d o c c u r r e d in few h a b i t a t types. On this basis we have a c c o r d e d species within these g r o u p s a p r o b a b l e c o n s e r v a t i o n status as in T a b l e 9. F o l l o w i n g is a closer c o n s i d e r a t i o n o f the c o n s e r v a t i o n status o f species within these g r o u p s :

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G r o u p A c o n t a i n s species with a c o n s e r v a t i o n status o f ' v u l n e r a b l e ' in the wheatbelt. There are two s u b g r o u p s : Al~ontains species which were on average f o u n d in less reserves, m o r e infrequently r e c o r d e d a n d m o r e habitat-specific t h a n o t h e r groups. One species, Artamus minor+ is a n o r t h e r n species which i n t r u d e s only into the n o r t h e a s t c o r n e r o f the w h e a t b e l t ; a n o t h e r , Streptopelia senegalensis, is an exotic which flourishes in u r b a n situations t h r o u g h o u t the wheatbelt. This leaves the following species as having the m o s t ' v u l n e r a b l e ' status in the w h e a t b e l t : Calyptorhynchus magm)qcus, Dacelo gigas (also an exotic),

Petroica multicolor, Falcunculus frontatus, Cinclosoma castanotum, Acanthiza inornata, Stipiturus malachurus, a n d Climacteris ruja. It is A2

n o t a b l e t h a t all six passerines are P5 species. on average f o u n d on slightly m o r e reserves, m o r e frequently r e c o r d e d a n d less habitat-specific t h a n species in the A I group. It includes two species Cheromoeca leucosterna a n d Anthus novaeseelandiae which, while n o t c o m m o n l y r e c o r d e d in reserves, occurred extensively in p a d d o c k s , r o a d verges or o t h e r d i s t u r b e d areas and as such have been f a v o u r e d by clearing o f land in the wheatbelt. TABLE 9

C O N S E R V A T I O N S T A T U S ()F RESIDENT PASSERINE A N D N O N - P A S S E R I N E G R O U P S IN W H E A T B E L T RESERVES. SPECIES WERE G R O U P E D BY F U R T H E S T N E I G H B O U R C L U S T E R ANALYSIS O N THE BASIS OF THE N U M B E R OF RESERVES THEY O C C U P I E D ; N U M B E R OF O C C A S I O N S THEY WERE R E C O R D E D AS PRESENT IN D I F F E R E N T A S S O C I A T I O N S , O R THE SAME A S S O C I A T I O N B U T AT D I F F E R E N T SEASONS; A N D N U M B E R OF FINE VEGETATION TYPES THEY O C C U P I E D ( L F D s ) (see Methods). I N D I V I D U A L SPECIES W I T H I N THESE G R O U P S C A N BE O B T A I N E D FROM F I G U R E 7 A N D A P P E N D I X I.

A A B B C D

Species group

No. .speeies

No. reserve,s

(i) (ii) (i) (ii) (i)&(ii) (i)&(ii)

10 8 6 5 15 11

2"4(1 4) 5.6(3 8) 10.2(8 12) 13.4(11 15) 16-4(14 22) 20.5(18 22)

Mean and range No. sightings in associations

No. L FDs

4-6(2 7) 3.1(1 5) 16.6(8 24) 6.1(2 9) 27.7(21 41) 11.5(10 13) 43.4(33 58) 15.6(15 17) 79.2(29 141) 16.9(9 25) 167.5(118 272) 23.4(19 28)

Conservation status

vulnerable vulnerable uncertain uncertain secure secure

This leaves the following species with a 'vulnerable" status: Platvcercus icterotis, Eurostopodus guttatus, Microeca leucophaea. Mahlrus .wlendens, M. lamberti a n d M. leucopterus. All f o u r passerines are P5 species. The status o f Eurostopodus guttatus is difficult to assess because it is n o c t u r n a l a n d its h a b i t a t specificity difficult to determine. G r o u p B c o n t a i n s species o f an u n c e r t a i n c o n s e r v a t i o n status. BI On average these were in 10 reserves and were r e a s o n a b l y h a b i t a t specific. It included Cracticus nigrogularis which was f a v o u r e d by land clearing.

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This leaves Turnix varia, Sericornis Jrontalis, S. cautus, S. fuliginosus and Daphoenositta chrysoptera as being of uncertain status. B2--These were in about 13 reserves and were less habitat-specific than the B1 subgroup. It included Manorinaflavigula, which was favoured by land clearing. This leaves Leipoa ocellata, Platycercus varius, Eopsaltria australis and Malurus pulcherrimus as being of uncertain status. Groups, C and D contain species considered to be relatively secure in the wheatbelt (see Fig. 7 and Appendix I). Ten of the 12 species with a clear preference for woodland (Appendix I) have a 'vulnerable' or uncertain conservation status. The long-term persistence of these species would seem to be extremely doubtful because of the continuing reduction of woodland in the region (see also Saunders (1979)); the exceptions are Cracticus nigrogularis, which is increasing in the wheatbelt and is only found in reserves where the vegetation is very open, and the exotic, Streptopelia senegalensis, which is increasing in numbers in the region. Comparison between our observations on birds in the wheatbelt with those of earlier ornithologists (Leake, 1962; Masters & Milhinch, 1974; Serventy & Whittell, 1976; Davies, 1977; Dell, 1977, 1978; de Rebeira & de Rebeira, 1977; Serventy, 1977) show that a further four non-passerine and ten passerine species categorised by us as 'non-residents' (including those of unknown resident status) are threatened in the wheatbelt; this is judged on the basis that they have experienced a numerical decline and/or distributional contraction in the region. Four of these species

(Eupodotis australis, Psophodes nigrogularis, Pachycephala inornata, Amytornis textilis) were not recorded by us in our surveys on reserves or their surrounds and so must be considered threatened in the region; the others are Dromaius novaehollandiae, Polvtelis anthopeplus, Calyptorhynchus latirostris, Meliphaga ornata, M. cratitia, Myiagra inquieta, Coracina maxima, Petroica cucullata, A rtamus cyanopterus, and Cracticus torquatus. Having identified some 23 resident and 14 'non-resident' bird species of 'vulnerable' or uncertain conservation status in the wheatbelt, it is important to note that of the wheatbelt species probably only Psophodes nigrogularis is endangered as a species over its Western Australian range (Smith, 1977), Only three species (Calyptorhynchus latirostris, Malurus pulcherrimus and Sericornis cautus) have a large part of their distribution in the wheatbelt; however, the last two species are still abundant south and east of the wheatbelt, but C. latirostris is confined largely to the wheatbelt. Bird species (excepting water birds) that have increased in numbers in the wheatbelt, or expanded their distribution to encompass the region, are without exception drier-country species. Serventy (1977) attributed most changes in bird distributions during the past century or so to climatic fluctuations. We agree with Davies (1977) that land clearing, particularly when it involves woodland, is related to expansions into the wheatbelt of the seed-eating arid-zone birds and consider it

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the most important factor in these e x p a n s i o n s - - a n d also for those non-seed eating arid species (Cracticus nigrogularis and A rtamus cinereus) that have increased in numbers in the wheatbelt. Environmental fluctuations have played a minor role in affecting the reduced distribution of species that have declined in abundance in the wheatbelt. As we have shown, most species that have declined rely on natural habitat (particularly woodland) that has declined in extent and quality in the wheatbelt. Size of conservation reserves." Although most of the resident bird species in a given locality were probably present in wheatbelt reserves of 1500ha, no single reserve studied contained more than 39 resident species or 71 ~o of the known resident species in the region. The size of a single area required to contain all passerine and non-passerine resident species in the wheatbelt can be approximated by substituting S = 55 in the equation which best describes this species versus area relationship. This equation is S = 3 . 1 7 + 10.421ogA (r =0.89). By extrapolation, a single area of about 94,000 ha would be required to hold all 55 species. To retain 90 ~o of them an al ea of 31,000 ha would be required. The latter size is probably the more reasonable estimate (Simberloff & Abele, 1976), given that several resident species already discussed, now have restricted distributions in the region, and probably also did prior to European settlement of the South West; several other resident species are also thought to be ecologically vicarious. These estimates are in the same order of magnitude as our estimate of 43,000 ha for a reserve to contain all extant species of m a m m a l s in the wheatbelt (Kitchener, 1980b). It is vastly less than the estimate for lizards in the region of 1-1 x l0 Tha (see Kitchener etal., 1980a,b). It is emphasized that these extrapolated estimates should be used with considerable caution for reasons referred to in these earlier associated papers; it is noted, however, that the slopes for species versus area relationships for birds may decline with increasing area (Abbott, 1973; Schoener, 1976), so that our above estimates may well be conservative. Kitchener et al. (1980a) proposed that in a heterogeneous environment, such as the wheatbelt, the size of nature reserve required to maintain most of the extant lizard species would be too large to be politically acceptable. It was therefore suggested that the only practical policy in such a situation may be to establish nature reserves of an ' o p t i m u m a r e a ' - - a size above which local (or subregional) species richness increases but slowly. Nature reserves of such a size should be distributed to encompass habitat types perceived as important to the taxa in question. The single area required to hold most extant species of birds (and mammals) in the wheatbelt is considerably smaller than the area required for lizards, perhaps by as much as a factor of 120. Only six of the 23 resident species of 'vulnerable' or uncertain status in the wheatbelt are resident on 200 South West islands for which records are available (see Abbott, 1978 and listed references, and |. Al~bott, pers. comm.). These six species, followed in brackets by islands on which they are resident and size range of these islands, are as follows: Sericornisfrontalis (Dirk Hartog, Bernier, Dorre, East &

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West Wallabi, Rottnest, Bald, Mondrain, Middle, and Salisbury Is, 309-59,600 ha); S.Juliginosus (Dirk Hartog and Dorreils, 4300 59,600 ha); Malurus lamberti (Dirk Hartog, Bernier and Dorre Is, 4300 59,600ha); M. leucopterus (Dirk Hartog Is, 59,600ha); Stipiturus malachuru~s (Dirk Hartog ls, 59,600ha); and Turnix varia (East & West Wallabi Is, 309 610ha). Of these six species four (Malurus leucopterus, M. lamberti, Stipiturus malachurus, and SericornisJuliginosus) are not found on islands smaller than 4300 ha, and two are found only on Dirk Hartog Is of 59,600 ha. While it is not wise to make too much of the absence of species from islands (Kitchener et al., 1980a) it is noted that perhaps only two of the 23 resident species of 'vulnerable' or uncertain conserwltion status in the wheatbelt (SericornisJ?ontalis, Turnix varia) are known to be able to survive in the long term on South West islands smaller than our predicted ' o p t i m u m area' for subregional nature reserves of about 1500 ha. This further suggests that need for additional (regional) nature reserves which are larger in area than 40,000 ha to support the subregional reserves. Nonetheless small nature reserves in the wheatbelt are also of value in the conservation of birds. For example, East Yorkrakine Nature Reserve (81 ha), which has probably been isolated from other natural vegetation by farmland for a period of at least 50 years, still contains four species of 'vulnerable' or uncertain conservation status in addition to 24 other resident species of birds. Small reserves also provide breeding areas for the more mobile and migratory species and as such form valuable ~stepping stones' for seasonal invaders to move through the wheatbelt. We have observed almost all resident bird species in wheatbelt road verges and consider that the long-term viability of the wheatbelt nature reserve system would be considerably enhanced if natural vegetation on road and railway verges and other corridors of vegetation linking reserves throughout the region could be protected by careful management and in most instances by widening verges. This would allow immigration to counter effects of inbreeding in small populations (Hooper, 1971) and allow for reinvasion of more mobile species into reserves following catastrophes to the fauna, such as those caused by fire. Saunders (1977) provides evidence for the importance of road verges to the wheatbelt avifauna: the black cockatoo Calyptorhynchus baudini ( = latirostris) required road verges to lead them from one food source to another. Absence of road verges resulted in these cockatoos having to search more widely for food, thereby probably diminishing their chances of survival (see also MacArthur & MacArthur, 1961; Wegner & Merriam, 1979). While the wheatbelt has about 22 nature reserves (excluding aquatic reserves) larger than 1500 ha, and one reserve larger than 40,000 ha (Lake Magenta Nature Reserve: 94,170 ha), these reserves inadequately represent the central and northern wheatbelt. Most of them, including Lake Magenta, carry very poor representation of woodlands, a vegetation formation considered by us in this paper, and in the two earlier related papers, to carry the richest assemblage of birds (and mammals and reptiles). This absence of adequate representation of woodlands and poor

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representation of larger reserves in parts of the wheatbelt poses a major threat to the long-term adequacy of the wheatbelt nature reserve system for the conservation of birds and other vertebrate fauna. Unfortunately very little relatively natural vegetation remains in the wheatbelt for future reservation within nature reserves, so that much of the value of our observations lies in the future planning of nature reserves in areas peripheral to the wheatbelt such as the Goldfields immediately to the east of the wheatbelt. The southern part of the Goldfields is potentially suitable for wheat-growing and other farming practices, and in fact remains the largest tract of essentially untouched potential farming country in Western Australia. We would stress, however, that most land in the Goldfields receives less rainfall than the wheatbelt and as a result its carrying capacity for some fauna may be less; this appears to be the case with birds (Dell, unpublished data). Nature reserves in the Goldfields ought to be larger than in the wheatbelt. For conservation of birds in heterogeneous regions such as the Western Australian wheatbelt it is probably necessary to have subregional reserves consisting of an ~optimum area' of not less than 1500 ha and containing adequate representation of local vegetation structural and floristic elements. These subregional reserves should then be placed within the region as elaborated above. Such reserves should be able to retain the extant subregional assemblages of birds, lizards, and probably most extant mammal species (see also Kitchener et al., 1980a,b). In addition it is desirable to have an example of the regional ecosystem that retains representatives of most birds in the region. This requires a considerably larger reserve not less than 40,000 ha containing representatives of the major regional habitats (it is noted, however, that, although such a large reserve may hold most species of mammals, it will almost certainly not retain a regional representation of lizards). This larger reserve should be duplicated elsewhere in the region as protection against agencies of attrition, particularly fire, which in the longer term will cause changes in habitat and fauna within all reserves. ACKNOWLEDGEMENTS

The vegetation study by B. G. Muir was wholly supported by an Australian Biological Resources Study G r a n t to D . J . Kitchener. The Western Australian Department of Fisheries and Wildlife defrayed most of the other field expenses, with the exception of surveys conducted in 1975, which were largely met from a grant by the Regional Employment Development Scheme to D.J. Kitchener. The Western Australian Department of Environment and Conservation made available a salary to enable B.G. Muir to complete his last two months' data collation. We gratefully acknowledge the field assistance of Messrs K . D . Morris, M. Jackson, G. Barron, A. Chapman, G. Harold and R . E . Johnstone, Western Australian Museum.

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W e t h a n k I. A b b o t , W e s t e r n A u s t r a l i a n F o r e s t s D e p a r t m e n t , S. J. J. F. D a v i e s , C S I R O , D i v i s i o n o f W i l d l i f e R e s e a r c h , R. A . H o w a n d G . M . S t o r r , W e s t e r n Australian Museum, and A.R. Main, University of Western Australia, for their c o m m e n t s on the m a n u s c r i p t . M a u r e e n Wallis typed the m a n u s c r i p t .

REFERENCES ABBOTT, I. (1973). Birds of Bass Strait. Proc. R. Soc. Vie., 85, 197-223. ABBOTT, 1. (1978). Factors determining the number of land bird species on islands around south-western Australia. Oecologia (Berl.), 33, 221 33. BEADLE,N. C. W. & COSTIN, A. B. (1952). Ecological classification and nomenclature. Proc. Linn. Soc. N.S.W., 77, 61 82. BROWN, J. H. (1971). Mammals on mountain tops: non equilibrium insular biogeography. Am. Nat., 105, 467-78. CARTER, T. (1923). Birds of the Broome Hill District. Emu, 23, 125 42. CHAPMAN,A., DELL,J., JOHNSTONE,R. E. & KITCHENER,D. J. (1977). A biological survey of Cockleshell Gully Reserve, Western Australia. Rec. West. Aust. Mus. Suppl., no. 4, 87 pp. CHAPMAN, A., DELL, J., KITCHENER, D. J. & MUIR, B. G. (1978). Biological survey of the Western Australian wheatbelt, Part 5: Dongolocking Nature Reserve. Rec. West. Aust. Mus. Suppl., no. 6, 80 pp. CHAPMAN, A., DELL, J., KITCHENER, D. J. & MUIR, B. G. (1980). Biological survey of the Western Australian wheatbelt Part 11 : Yorkrakine, East Yorkrakine and North Bungulla Nature Reserves. Rec. West. Aust. Mus. Suppl., no. 12, 71 pp. CHAPMAN,A., DELL, J., KITCHENER, D. J. & MUIR, B. G. (1981). Biological survey of the Western Australian wheatbelt, Part 13. Billyacatting Hill Nature Reserve. Rec. West. Aust. Mus. Suppl., no. 13, 54pp. CLIFFORD, H. J. & STEPHENSON, W. (1975). An introduction to numerical classification techniques. New York, Academic Press. CODV, M. L. (1975). Towards a theory of continental species diversity: bird distributions over mediterranean habitat gradients. In Ecology and evolution ofcornmunities, ed. by M. L. Cody and J.M. Diamond, 214-57. Cambridge, 'Massachusetts, and London, England, Belknap Press. CONNOR, E. F. & McCoY, E. D. (1979). The statistics and biology of the species area relationship. Am. Nat., 113, 791-833. CROSSMAN, A. F. (1909). Birds seen at Cumminin Station, Western Australia. Emu, 9, 84-90. DAVIES, S. J. J. F. (1977). Man's activities and birds' distribution in the arid zone. Emu, 77, 169 72. DAVIES,S. J. J. F. (1979). The breeding seasons of birds in south-western Australia. J. Proc. R. Soc. West. Aust., 62, 53 64. DELL, J. (1976). Birds of Lake Magenta wildlife sanctuary, Western Australia. Rec. West. Aust. Mus., 4, 117 32. DELL, J. (1977). Birds of Bendering and West Bendering Nature Reserves. Rec. West. Aust. Mus. Suppl., no. 5, 31-46. DELL, J. (1978). Birds of Dongolocking Nature Reserve. Rec. West. Aust. Mus. Suppl., no. 5, 59-70. DELL, J., HAROLD,G., KITCHENER,D. J., MORRXS,K. D. & MUIR, B. G. (1979a). Biological survey of the Western Australian wheatbelt, Part 7. Yornaning Nature Reserve. Rec. West. Aust. Mus. Suppl., no. 8, 48 pp. DELL, J., CHAPMAN,A., KITCHENER, D. J. & Mum, B. G. (1979b). Biological survey of the Western Australian wheatbelt, Part 8. Wilroy Nature Reserve. Rec. West. Aust. Mus. Suppl., no. 8, 54pp. DELL, J., CHAPMAN,A., K1TCHENER, D. J. & MUIR, B. G. (1979c). Biological survey of the Western Australian wheatbelt, Part 9. Marchagee Nature Reserve. Rec. West. Aust. Mus. Suppl., no.8, 50 pp. DELL, J., CHAPMAN,A., KITCHENER, D. J. & MUIR, B. G. (1981). Biological survey of the Western Australian wheatbelt, Part 14, East Yuna and Bindoo Hill Nature Reserves. Rec. West. Aust. Mus. Suppl., no. 13, 100pp. DEREBEIRA,C. P. S. & DEREBEmA,A. M. ( 1977). Birds. In The natural history o f the Wongan Hills, 77-96. Perth, Western Australian Naturalists' Club.

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FORD, J. R. & STONE, P. S. (1957). Birds of the Kellerberrin/Kwolyin district, Western Australia. Emu, 57, 9-21. FORD, J. (1970). Distribution and variation of the southern emu-wren in Western Australia. West. Aust. Nat., 11, 116-20. FORD, J. (1971). Distribution, ecology and taxonomy of some Western Australian passerine birds. Emu, 71, 103-20. HALSE, S. A. (1977). Feeding habits of six species of honeyeater in south-western Australia. Emu, 78, 145~,8. HOOPER, M. D. (1971). The size and surroundings of nature reserves. In The scientific management o/ animal andplant communities for conservation, ed. by E. Duffey and A. S. Watt, 551-61. Oxford, Blackwell Scientific Publications. JOHNSON, M. P., MASON, L. G. & RAVEN, P. H. (1968). Ecological parameters and plant species diversity. Am. Nat., 102, 297-306. KARR, J. R. &ROTH, R. R. (1971). Vegetation structure and avian diversity in several new world areas. Am. Nat., 105, 423-35. KITCHENER, D. J., CHAPMAN,A. & DELL, J. (1975). A biological survey of Cape I 2 Grand National Park. Rec. West. Aust. Mus. Suppl., no. 1, 48 pp. KITCHENER, D. J. (1976). Preface to the biological survey of the Western Australian wheatbelt. Rec. West. Aust. Mus. Suppl., no. 2, 3 10. KITCHENER, D. J., CHAPMAN, A., DELL, J., JOHNSTONE, R. E., MUIR, B. G. & SMITH, L.A. (1976). Biological survey of the Western Australian wheatbelt, Part 1. Turin Rock and North Turin Rock Reserves. Rec. West. Aust. Mus. Suppl., no. 2, 11-87. KITCHENER, n . J., CHAPMAN, A., DELL, J. • MUIR, S. G. (1977). Biological survey of the Western Australian wheatbelt, Part 3. Vertebrate fauna of Bendering and West Bendering Nature Reserves. Rec. West. Aust. Mus. Suppl., no. 5, 58pp. KITCHENER, n . J., CHAPMAN, A., DELL, J. t~. MUIR, B. G. (1979). Biological survey of the Western Australian wheatbelt, Part 10. Buntine, Nugadong and East Nugadong Nature Reserves and Nugadong Forest Reserve. Rec. West. Aust. Mus. Suppl., no.9, 127 pp. KITCHENER, D. J., CHAPMAN, A., DELL, J., MUIR, B. G. & PALMER, M. (1980a). Lizard assemblage and reserve size and structure in the Western Australian wheatbelt--some implications for conservation. Biol. Conserv., 17, 25-62. KITCHENER, D. J., CHAPMAN,A., MUIR, B. G. & PALMER,M. (1980b). Conservation value for mammals of reserves in the Western Australian wheatbelt. Biol. Conserv., 18, 177 205. LEAKE, B. W. (1962). Eastern wheatbelt wildlife. Perth, B. W. Leake. MACARTHUR, R. H. & MACARTHUR, J. W. (1961). On bird species diversity. Ecology, 42, 594-8. MACARTHUR, R. H. (1964). Environmental factors affecting bird species diversity. Am. Nat., 98, 387 97. MACARTHUR, R., RECHER, H. & COPY, M. (1966). On the relation between habitat selection and species diversity. Am. Nat., 100, 319 32. MACARTHUR, R. H. & WILSON, E. O. (1967). The theory of island biogeography. Princeton, New Jersey, Princeton University Press. MAIN, A. R. (1979). Fauna. In Environment and Science (Sesquicentennial celebration series), ed. by Brian J. O'Brien, 77 100. Nedlands, Western Australia, University of Western Australia Press. MASTERS, J. R. t~ MILHINCH, A. L. (1974). Birds of the Shire of Northam, about 100 km east of Perth, Western Australia. Emu, 74, 228-44. MAYR, E. & SERVENTY, D. L. (1938). A review of the genus ,4canthica Vigors and Horsfield. Emu, 38, 245-92. MILLIGAN, A. (1904). Notes on a trip to the Wongan Hills, Western Australia. Emu, 3, 217 26. MUIR, B. G. (1977a). Biological survey of the Western Australian wheatbelt. Part 2: Vegetation and habitat of Bendering Reserve. Rec. West. Aust. Mus. Suppl., no. 5, 142pp. MUIR, B. G. (1977b). Biological survey of the Western Australian wheatbelt. Part 4: Vegetation of West Bendering Nature Reserve. Rec. West. Aust. Mus. Suppl., no. 5, 31 pp. MUIR, B. G., CHAPMAN, A., DELL, J. & KITCHENER, D. J. (1978). Biological survey of the Western Australian wheatbelt, Part 6. Durokoppin and Kodj Kodjin Nature Reserves. Rec. West. Aust. Mus. Supp., no. 7, 77 pp. MUIR, B. G., CHAPMAN, A., DELL, J. & KITCHENER, D. J. (1980). Biological survey of the Western Australian wheatbelt, Part 12. Badjaling and South Badjaling Nature Reserves, Yoting Town and Yoting Water Reserve. Rec. West. Aust. Mus. Suppl., no, 12, 66pp. ORTON, C. L. E. & SANDLAND, P. T. (1913). Birds of Moora (WA) and District. Emu, 13, 75 80. POLUNIN, N. (1960). Introduction to plant geography. London, Longman.

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RECHEg, H. (1969). Bird species diversity and habitat diversity in Australia and North America. Am. Nat., 103, 75-80. ROTH, R. R. (1976). Spatial heterogeneity and bird species diversity. Ecology, 57, 773 82. SANDLANO, P. & ORION, C. L. E. (1923). List of birds found breeding in and around the swamps near Moora, WA, during 1921. Emu, 22, 134-7. SAUNDERS, D. A. (1977). The effect of agricultural clearing on the breeding success of the white-tailed black cockatoo. Emu, 77, 180--4. SAUNDERS, D. A. (1979). The availability of tree hollows for use as nest sites by white-tailed black cockatoos. Aust. J. WiM. Res., 6, 205 16. SCHOENER,T. W. (1976). The species-area relation,within the archipelago: models and evidence from island land birds. In Proc. int. Ornith. Congr., 16th, ed. by H.J. Frith & J. H. Calaby, 629 41. Canberra, Australian Academy of Science. SEDGWICK,E. H. (1949). Bird movements in the wheatbelt of Western Australia. West. Aust. Nat., 2, 25-33. SERVENTY, D. L. (1977). The use of data on the distribution of birds to monitor climatic changes. Emu, 77, 162-6.

SERVENTY,D. L. & MARSHALL, A. J. (1957). Breeding periodicity in Western Australian birds: with an account of unseasonal nestings in 1953 and 1955. Emu, 57, 99 126. SERVENTY, D. U & WmTTELL, H. M. (1976). Birds" of Western Australia, 5th edn. Perth, University of Western Australia Press. SERVFNTY, V. (1958). Bird notes from the Dumbleyung camp-out, 1956. Emu, 58, 5-20. S1MBERLOFF,D. S. 8~,ABELE, L. G. (1976). Island biogeography theory and conservation practice. Science, N.Y., 191,285-6. STORR, G. M. & JOHNSTONE, R. E. (1979). Field guide to the birds of Western Australia. Perth, Western Australian Museum. SMITH, G. T. (1977). The effect of environmental change on six rare birds. Emu, 77, 173 9. TERBORGH, J. (1977). Bird species diversity on an Andean elevational gradient. Ecology, 58, 1007- 19. TOMOFF, C. S. (1974). Avian species diversity in desert scrub. Ecology, 55, 39(~403. TRAMER, E. J. (1969). Bird species diversity: components of Shannon's formula. Ecology, 50, 927 9. WEGNER,J. F. & MERRIAM, G. (1979). Movements by birds and small m a m m a l s between a wood and adjoining farmland habitats. J. app/. Ecol., 16, 349 57. WILLSON, M. E. (1974). Avian c o m m u n i t y organisation and habitat structure. Ecology, 55, 1017 29. WtLSON, E. O. & WILL1S, E. O. (1975). Applied biogeography. In Ecology and evolution of communities, ed. by M. U Cody and J. M. Diamond, 522 34. Cambridge, Massachusetts, and London, England, Belknap Press. YEATON, R. I. (1974). An ecological analysis of chaparral and pine forest bird communities on Santa Cruz island and mainland California. Ecology, 55, 959 73.

17 18 19 20 21 22 23 24 25 26

15 16

12 13 14

11

10

1 2 3 4 5 6 7 8 9

No.

Dromaius noraehollandiae Podiceps polioceThalus A rdea pac!lqca Ardea noraehollandiae Tadorna tadornoidc.s Anas superciliosa Anas gibberij)'ons Chenonetta jubata Elanus caeruleus AccipiterJasciatus Accipiter cirrocephalus Aquila morphnoides Aquila audax Circus assimilis Fa/co peregrinus Falco Iongipennis Falco berigora Falco cenchroides Leipoa oce/lata Turnix raria Turnix t'elox Porzana pusilla Gallinula rentralis Vanellus tricolor Charadrius ru/icapillus Tringa stagnatilis

NON-PASSERINES

Species

A I A A

O

A C

0 0

0 0 0

A A A A

O O O O

C C C C C C C C C G Om G A

A

0

O O O O O O O O O R R O O

Om A

~,

~

O O

~

-~

1

1 1 1

7 3 3 13 2 2 4 10 7 11 12 1 1

1 2

2 7 2 2

1

9 1

~

~

1

1 1 3

14 3 9 30 2 4 7 35 13 33 21 1 1

2 2

1 17 2 8

2

31 2

~

~

1O0

72 67 67 60 100 50 72 40 23 37 14

1O0

71

7

"14/

25 14 3 23 30 24

11 17

14

32

M

28 15 12 38

3

7 33

32

S

25 14 23 23 12 14 100

22 10

7

1O0

26

U

9 10

3

10

L

8

B

SC

100

1O0

1O0

100

3 8

100 29 50 100

1O0

3 100

"o ~1 records in jormation tlpes

50

£"

1

? 1 1

8 3 3 11 1 4 4 11 7 17 12 1 1

2 3

1 5 ? 1

9

15 1

LFDs

150.0 97.7

WGT

APPENDIX I LIST OF NON-PASSERINE AND PASSERINE SPECIES IN WHEATBELT RESERVES, SHOWING THEIR: RESIDENCY STATUS (R, RESIDENT; O, 'NON-RESIDENTS); FEEDING TYPE ( O l n , OMNIVORE; m, AQUATIC SITUATIONS; C, CARNIVORE~ 1, INSECTIVORE; N, NECTARIVORE~ G , GRANIVORE; H , HERBIVORE), NUMBER OF WHEATBELT RESERVES OCCUPIED, NUMBER OF DIFFERENT ASSOCIATIONS OCCUPIED OR THE SAME ASSOCIATION BUT AT DIFFERENT SEASONS, PROPORTION OF THESE ASSOCIATION RECORDS IN DIFFERENT FORMATIONS.

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° o

.~-~

-

.~

E

000

~

0

0

~

0

0

~

0

r--

~

~

0

~

0

~

0

~

111

88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110

No.

Acanthiza chrvsorrhoa Pyrrholaemus brunneus Sericornis j)'ontalis* Sericornis cautus* Sericornis Juliginosus* Malurus splendens* Malurus lamberti* Malurus pulcherrimus* Malurus leucopterus* Stipiturus rnalachurus* Cinclorarnphus mathewsi Cincloramphus cruralis Daphoenositta chrysoptera Climacteris rujct* Dicaeum hirundinaceum Pardalotus punctatus Pardalotus striatus Zosterops lateralis Lichmera indistincta Meliphaga virescens Meliphaga ornata Meliphaga cratitia Meliphaga leucotis* Melithreptus brevirostris

Species R R R R R R R R R R O O R R O O O O O R O O R O Om I l H I I Om N I N N I I

20 15 9 8 11 3 4 12 3 4 1 2 9 2 3 6 21 9 20 22 3 4 15 21

118 141 41 22 23 19 22 43 24 4 2 2 29 7 5 19 93 31 214 272 11 9 132 75 66 100 80 79 78 26 25 24 82 33 43 53

100

5 5 2

45 14 7

A P P E N D I X I--contd.

27 12

20 II 3 16 39 43 18 5 18 10 14 10 67 27 31

50 3

19 62 56 14 9 68 72 47 21 50

S

50 24

25

26 6 12 63 4 11 5 12

M

1 3

39 12 15

7

2 11 15 23 83 11 18 33 21 25

H

1 1

5 1 3 5 4

6

3 3 7

L

1

3 1 1

5

1 1 3

B

3 4 2

54

4

3 3

SC

% oJ records injormation t37~es

1

4

1

X

22 25 13 10 13 8 9 15 6 4 2 2 10 3 4 9 11 15 29 28 5 5 18 18

8'6 11.7 10-7 12.3 13.0 9.7 8.0 6.8 7.1 5-3 26.4 39.3 13.1 32.8 7.5 6.9 10.6 10.6 11.3 24.0 17.6 19-8 20.7 12.0

L FDs ~'GT

~_

~"

m ~r-

.'-

m 7'

t~

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t2

Phylidonyris novaehollandiae Phylidonyris nigra Phylidonyris albifrons Phylidonyris melanops Acanthorhynchus superciliosus Manorinaflavigula Acanthagenys ruJbgularis Anthochaera chrysoptera Anthochaera carunculata Epthianuraalbifrons Poephilaguttata Grallinacyanoleuca Artamus cinereus Artamus cyanopterus Artamus minor Cracticustorquatus Cracticusnigrogularis Cracticustibicen Strepera versicolor Corvusbennetti Corvuscoronoides O O O O O R O O O O O O R O R R R R R O R

N N N N N Om Om N N I G I I I I C C Om Om Om Om

2 4 8 8 1 14 12 2 12 16 8 11 17 2 1 17 12 17 14 6 22

3 10 18 46 3 44 42 6 76 55 12 21 48 3 2 91 30 47 83 17 76 38 25 5

24 10 19 21 29 16

42 60 19 67 54 70 47 52 71 70

13 5

57 26 48

20

17 2

33

2 2 4

5

1

29

4 45 8

5

33 50 17 37 33

11 14 24 19

33 40 61 30 67 30 40 83 9 33 25 15 35

1

1 3 2 6

5 2

1 2

7

10 5

100 1

4

8 3 2

5 13

18

17 17

11

4

10 2 33

2

5 8 11 15 2 15 16 3 17 14 10 8 19 2 1 16 11 18 18 6 15

17-2 15.0 18.3 17.0 10.0 65-0 45.8 62.9 116.0 10.5 12-0 81"8 38.6 33.0 16.9 89-5 129.5 308-7 330.3 374.3 563.3

W, woodland + tree mallee; M, mallee; S, shrubland; H, heath; L, lithic complex: B, breakaway; Sc, salt complex: X, others; number of'fine" vegetation types occupied (LFDs) (see Methods) and body weight (g). Those species with an asterisk (*) are P5 species.

120 121 122 123 124 125 126 127 128 129 130 131 132

119

112 113 114 115 116 117 118

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