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Taphonomy of bats (Chiroptera)
TAPHONOMY OF BATS (CHIROPTERA)
KAZIMIERZ KOWALSKI KOWALSKI K_ 1995. Taphonomy of bats (Chiroptera). [Taphonomie de chauves-souris (Chiroptera)]. GEOBIOS, M.S. 18 : 251-256.
ABSTRACT Fossil localities containing remains of bats represent usually either fluvio-limnic or karstic sediments. The factors responsible for the accumulation of bones in these two types of localities may be different. Data on ecology and mortality of these animals accumulated by zoologists are necessary to understand the taphonomy of fossil bat localities. A review of such data, espcially those concerning the role of predators is given. KEY-WORDS : CHIROPTERA,TAPHONOMY,PREDATION,PALEOECOLOGY,
RI~SUMI~ Les faunes fossiles de chauves-souris se trouvent g4n6ralement dans les s6diments soit fluvio-lacustres, soit karstiques. Les facteurs responsables de l'accumulation des ossements dans ces deux types de sites peuvent ~tre diff6rents. Pour l'analyse de la taphonomie de localit4s de chauves-souris fossiles, les donn6es sur l'6cologie et surtout la mortalit6 de ces animaux accumul4es par les zoologistes sont indispensables. La revue de ces donn4es, surtout celles qui concernent le rSle de pr6dateurs, est pr6sent4e. MOTS-CL]~S : CHIROPTERA, TAPHONOMIE,PRI~DATION,PALI~OI~COLOGIE.
The number of studies concerning fossil bats has grown rapidly in the last few years. Nearly all are devoted to systematics and evolution, only a few refer to palaeoecology (e. g. Richter & Storch 1980, Sevilla 1988, 1989) and even less attention has been paid to the taphonomy of these animals. A paper by Sig4 & Legendre (1982) is an exception and it stresses the differences between the localities of fossil bats in fluvio-limnic sediments and those in sediments of karstic hollows. They concluded t h a t the taxonomic composition of the taphocoenoses of bats in these two types of sediments is different. Moreover, the remains in water deposits are scarce and usually of very fragm e n t a r y n a t u r e (although exceptionally represented by entire skeletons), whereas materials originating from k a r s t localities are as a rule numerous, well preserved and contain both skulls and postcranial bones in proportions similar to n a t u r a l ones.
Recent bat species m a y be divided into those which shelter in caves and rock fissures and those hiding mainly in tree hollows. This division is, however, not absolute. Members of some species use caves as hibernacula and tree hollows as roosts in the day time. Typical "forest" species m a y sporadically visit caves (Gaisler 1966). Finally, it must be noted t h a t even typical "cave" species h u n t insects in various habitats, including forests and, quite often, over bodies of water. Therefore, though some differences in composition and preservation of bats between karst and fluvio-limnic sediments ,are to be expected, numerous species m a y be common to both of fossil localities.
Zoological investigations, usually u n k n o w n to paleontologists, yielded m a n y interesting data
Knowledge of the factors influencing the mortality of bats would be useful for understanding
which can be used for a better u n d e r s t a n d i n g of the type of preservation of bats in their fossil assemblages, as well as of the qualitative and quantitative compositions of such assemblages.
252 of the composition of the bat fauna in different types of sites (Gilette and Kimbrough 1970). Our information in this respect is still very limited. It is well known that the life-span of bats is generally longer t h a n it is in other small m~mmals of similar size. The turnover of a population of bats is therefore several times slower than that of rodents and the n u m b e r of carcasses available for fossilisation smaller. This is one of the reasons w h y bats are usually rare as fossils. There are no quantitative studies on the share of different factors in b a t mortality. These factors are as follows : climatic phenomena, diseases, predators and accidents in flight. In temperate regions cold w e a t h e r is probably the most important factor controlling population size. Young a~imals are particularly endangered by unusually long winters and winter colonies in arboreal hibernacula sometimes freeze to death. Also accidents in flight, some connected with weather conditions (storms, heavy rainfall, etc.), m a y be responsible for the death of bats ; mass mortality in colonies m a y be the result of epidemics (Gilette & Kimbrough 1970). A particular type of preservation of bat remains in limnic sediments is represented by nearly complete skeletons found in anatomic order. The most famous locality with such specimens is Messel in Germany. There the sediments of an Eocene lake contain a rich vertebrate fauna, with Chiroptera as the dominant group (Richter & Storch 1980, Habersetzer & Storch 1989). The bats, belonging to 7 species, were in good condition before death, fragments of insects being sometimes recognizable in their stomachs. The preserved individuals are mainly adult, very few are young. No traces of predators have been discovered. Probably the bats were flying over a volcano lake and perished during periodic eruptions of carbon dioxide. Anoxic conditions at the bottom of the lake favoured the preservation of entire specimens. Other, more typical remains of bats preserved in fluvio-limnic sediments are isolated teeth or fragments of bones, among similar specimens belonging to other m~mma]Jan groups. Before deposition they were usually transported by water. In the Oligocene locality Carrascosa del Campo in Spain, Sevilla (1990) discovered remains of the genera Hipposideros, Rhinolophus and Megaderma in fluviatile sediments. These taxa are usually connected with caves and their fossils have hitherto been found together in karst localities. Sevilla is of the opinion that these remains, composed of numerous isolated teeth and fragments of mandibles, accumulated in karstic sediments and were later transported and redeposited by water.
Other of bat remains in the water-deposited sediments m a y be bones of these animals originating from the scat of predators. In karst localities (sediments of caves and fissures) massive accumulations of b a t remains are quite common. As a rule they are very well preserved and contain entire skulls and postcranial bones, although rarely in anatomic order. This type of preservation is exemplified by the Early Pliocene locality Podlesice in Poland where thousands of entire skulls with undamaged brain cases have been found (Kowalski 1956, Woloszyn 1987). Long postcranial bones are sometimes accumulated with their long axes extending in the same direction, this material being sorted by slowly flowing or dripping water, resulting in minimum d~mage to the bones. Today such accumulations of skeletons can be seen under winter colonies of cave bats. Dead and more or less disintegrated bats are common on the walls or floors of caves which are used as hibernacula. They derive from adult or subadult individuals. It is less likely that skeletons from s u m m e r bat colonies in caves should be preserved. The floor under such colonies is usually covered by guano, in which the remains of vertebrates (including bats) become totally dissolved. In karst sediments, particularly those deposited near the entrances of caves or in vertical wells and fissures, the remains of small vertebrates, especially of m~mmals, are very common. There is no doubt as to their taking rise from the food of avian and m~mmalian predators, of owls in particular. The localities of fossil bats in caves, in which these animals are preserved among other small vertebrates, m a y originate from the scat of predators. Many carnivores include bats in their diet when these are available. Known cases of such predation are generally restricted to the birth and nursery season and concern mainly young bats which have fallen to the floor from their colonies. There seem to be no predators as a group that consistently make bats their habitual prey, but there are individual predators whose diet consists regularly of bats (Gilette & Kimbrough 1970). The enemies of bats include snakes and sometimes other reptiles and amphibians, mainly in equatorial regions. Reptiles and amphibians dissolve bones of their prey during digestion and cannot contribute to the accumulations of bat remains. Mammalian carnivores sporadically h u n t bats, especially those living in large colonies in caves. The opportunistic killing of bats by opossums and
253 Australian carnivorous marsupials, shrews, p r i m a t e s , other bats and rodents can only exceptionally contribute to the accumulation of bat bones. In Povolshie in Russia, Iljin (1989) noted the regular presence of bat bones in the droppings of foxes (Vulpes vulpes), the latter hunting bats hibernating in man-made underground tunnels. In Nietoperek in Poland, Lesinski & Romanowski (1988) discovered excrements of the marten (Martes foina) in which the remains of bats constituted 81% of the total mass of remains.
best known owl species in Europe, Tyro alba and Strix aluco, bats constitute less t h a n 1% of all vertebrate individuals eaten (Tables 1-2). In many collections of owl pellets studied, no b a t remains have been noted : such data have not; been included in the tables. The actual percentage of bats in the food of these owls is therefore probably lower. The percentage of b a t remains depends in the first place on the presence of individual owls specializing in bat hunting.
The most important predators of bats are birds. Diurnal birds of prey, mainly falcons and hawks, have been observed hunting bats, usually at dawn or dusk. The objects of these attacks were mainly colonial species during their emergence and morning return (James & Hayne 1963). There are no published data on the effectiveness of such attacks, b u t these birds are not likely accumulators of b a t bones because they become more or less digested in their stomachs.
The data on the share of bats in the diet of particular owl species are not directly comparable b u t the genera] impression is that is is different. This share seems to be the highest in Strix aluco where it is 0.22 - 21.88% (m = 2.66) of the minimum number of individual (MNI) of vertebrates identified in pellets and 0.55 - 23.91% (m = 5.58) of the MNI of m~mmals. In Tyto alba it amounts to 0.12 - 54.74% (m = 0.35%) of vertebrates and 0.14 55.32% (m = 0.60) of mammals.
More attention has been devoted to the hunting of bats by owls. No owl species takes bats as a regular diet component b u t within species are individuals which specialize in attacking Chiroptera (Scbmidt & Topal 1971 ; Ruprecht 1979a, b, 1990 ; Nowosad & Salata-Pilacinska 1987 ; Lesinski 1989 ; Obuch 1992). The proportion of bats in the food of owls is u s u a l y negligible. In the two
In the food remains of Bubo bubo in Europe, the number of bats is insignificant (Jgnossy and Schmidt 1970). In Morocco, however, according to Lesne & Thevenot (1981) bats constituted 1.04% of the MNI of vertebrates eaten by Bubo b. ascalophus. The majority of the collections of pellets deposited by this species in other regions did not contain any bat remains.
-
MNI of bats
Vertebrata % of MNI bats
Mammalia % of i MNI bats
4
480
0.34
278
1.45
4 localities, forest area
13
_
_
1,711
0.76
numerous localities, forest area
_
_
21.88
389
23.91
at the cave entrance
1,344
0.22
547
0.55
1 suburban locality
10
267
3.75
223
4.48
numerous localities, submontain area
7
2,668
0.26
_
_
LOCALITY
AUTHOR
Bialowieza, N. Poland
Ruprecht & Szwagrzak1987
Nadnotecka Puszcza, N. Poland
Ruprecht 1990
Central Poland
Nowosad & Salata-Pilacid'ska 1987
87
Szachownica, Poland
Kowalski & Lesir~ski 1990
93
425
Krak6w, S. Poland
Bocheriski 1990
3
Beskid Niski, S. Poland
Kulczycki 1964
Sachsen, Germany
M&rz 1954
SIovakia
Obuch 1992
14,269 0.61
847 20,088 4.22 15,782 5.37
REMARKS
38 localities, different environments
31 localities 5 localities at cave entrances
Table 1 - The p r o p o r t i o n of b a t s a m o n g food r e m a i n s of S t r i x a l u e o in Europe. MNI = M i n i m u m n u m b e r of individuals. Porportion de chauves-souris p a r m i les restes de nourriture S t r i x a l u v o en Europe. M N I =nombre minimal d'individus.
254
MNI LOCALITY
AUTHOR
REMARKS
MNI
MNI
%of bats
52
95
54.74
94
55.32
1 locality
Cajs 1963
10
4,795
0.21 4?662
0.21
collection from 19 localities
Beskid Niski, Poland
Kulczycki 1964
15
3,326
0.45 3?2999 0.45
Poznan, N. Poland
Czarnecki et aL 1955
28
13,628 0.21 13,014 0.22i
Lublin, SE Poland
Nikodem 1982
137 64,375 0.21
_
_
several localities, in buildings
Nadnotecka Primeval Forest, NW Poland
Ruprecht 1990
26
21,036 0.12
_
_
forest
Central Poland
Nowosad, Salata-Pilacir{ska 1987
87
14,265 0.61
_
_
38 localities, in church towers
Balowieza
Ruprecht, Szwagrzak 1987
3
2,156
2,100
0.14
9localities
Kujawy, C. Poland
Ruprecht 1979
46
16,944] 0.27 13,394 0.34
9localities
Cabra, SW Spain
Herrera 1973
133
9,329
1.43
8,449
1 locality
SW Spain
Herrera 1973
8
4,827
0.17
4,441 0.18
Przemy~l, Poland
Bauer 1956
Mammalia
%of bats
G0ssig, Austria
of bats
Vertebrata
0.14
1.57
several localities 14localities
23 localities in SW Spain (exc. Cabra)
Table 2 - The proportion of bats among the food remains of Tyto alba in Europe. MNI = Minimum number of individuals. Porportion de chauves-souris parmi les restes de nourriture Tyro alba en Europe. MNI =nombre minimal d~ndividus. The differences in the role of bats as food for particular individuals of owls have already been mentioned. In Gtissig in Austria Bauer (1956) found an accumulation of pellets deposited by Tyro alba in a loft inhabited also by a big colony of bats (mainly Myotis myotis and Miniopterus schreibersi). 54.74% of the MNI of vertebrates in these pellets were bats belonging to the species present in the neighbouring colony. Kowalski & Lesinski (1990) studied the pellets of Strix aluco found in the entrance hall of Szachownica Cave in Poland and under the trees outside the entrance : bats constituted 21.88% of al] individuals of vertebrates. In Slovakia bats were found to make up 4.22% of the MNI of vertebrates in the pellets collected at 5 roosts of owls of the same species, situated at the entrances of caves (Obuch 1922). All the indi-
viduals of Strix aluco studied by Obuch regularly h u n t e d bats. In the majority of cases the remains of bats in the food of owls are so scarce t h a t it is evident t h a t the consumption of these animals was accidental and did not result from the definite food preferences of a particular individual. Some species of bats are more numerous in the food remains of owls t h a n others. For example in Poland (Nowosad & Sata-Pilacinska 1987, Ruprecht 1990) the most frequently t a k e n bats are : Eptesicus serotinus, Nyctalus noctula and Plecotus (P. auritus and P. austriacus). Scbmidt & Topal (1971) in H u n g a r y also noted t h a t Eptesicus serotinus and Nyctalus noctula top on the list of bats hunted by owls. Knowledge of the population density of bats is unfortunately so limited t h a t it is impossible to decide wheter this is due to the
255 h i g h e r n u m b e r s of i n d i v i d u a l s of t h e s e p a r t i c u l a r p r e y species or to t h e selectivity of p r e d a t o r s . K r z a n o w s k i (1973) a n a l y z e d t h e s h a r e of diff e r e n t f~milies of bats in t h e food of owls a n d c a m e to t h e conclusion t h a t t h e Rb2nolophidae are u n d e r - r e p r e s e n t e d , c o m p a r e d w i t h t h e Vesp e r t i l i o n i d a e . H e explains it b y a q u i c k e r escape r e a c t i o n ability of h o r s e - s h o e bats. A u l a g n i e r (1989) holds a s i m i l a r opinion. T h e r e are no published d a t a on t h e existence of p r e f e r e n c e for part i c u l a r species of c h i o p t e r a n p r e y in p a r t i c u l a r species of owls : a n o p p o r t u n i s t i c a p p r o a c h seems to be domirlant. O n t h e o t h e r h a n d t h e r e are significant geographical differences in p e r c e n t a g e s of b a t s in t h e owls' food (see tables 1-2) a n d in t h e specific composition of b a t species eaten. T h e y are e v e n evid e n t in s u c h a r e l a t i v e l y u n i f o r m t e r r a i n as t h a t of P o l a n d ( R u p r e c h t 1990). T h e selectivity of owls would be b e t t e r und e r s t o o d ff t h e i r m e t h o d s of h u n t i n g bats w e r e b e t t e r k n o w n . H a r d l y a n y observations are available ; some a u t h o r s suppose t h a t owls c a p t u r e b a t s in flight, p e r h a p s m a i n l y d u r i n g seasonal migrations. D e t e r m i n a t i o n of t h e age of c a p t u r e d bats w o u l d be of some i m p o r t a n c e . Y o u n g b a t s are b o r n w i t h m o r e or less developped deciduous t e e t h w h i c h are g e n e r a l l y r e p l a c e d b y p e r m a n e n t t e e t h b y t h e t i m e t h e y can fly a n d feed i n d e p e n d e n t l y (Anthon y 1990). S u c h studies h a v e not b e e n conducted in t h e case of bats, t h e r e f o r e we are u n a b l e to decide w h e t e r t h e fossil bones o r i g i n a t e d from t h e scat of p r e d a t o r s or not. B y a n a l o g y w i t h o t h e r small m a m m a l s , we can o n l y suppose t h a t t h e p r e s e n c e of u n d a m a g e d b r a i n cases excludes t h e scatological origin of t h e skulls. T h e s e p a r t s of skulls are u s u a l l y t h e first to be d e s t r o y e d b y c h e w i n g a n d digestion. P r o b a b l y p r e d a t o r s do not p l a y such a d o m i n a n t role in t h e a c c u m u l a t i o n of b a t r e m a i n s as in t h e case of o t h e r orders of small m a m m a l s . T h e y m a y n e v e r t h e l e s s be significant in t h e a c c u m u l a t i o n of c h i r o p t e r a n r e m a i n s in fluvio-lacustrine sedim e n t s a n d in k a r s t i c s e d i m e n t s in which b a t bones are m i x e d w i t h t h o s e of r o d e n t s a n d insectivores. F u r t h e r zoological s t u d i e s ( p a r t i c u l a r l y t h o s e concerning t h e m o r t a l i t y of bats) are n e e d e d to increase o u r k n o w l e d g e of t h e t a p h o n o m y of fossil bat f a u n a s . In i n v e s t i g a t i o n s of fossil b a t localities it s h o u l d be obligatory to r e g i s t e r t h e n u m -
be÷ of individuals of p a r t i c u l a r species, t h e age of individual specimens, t h e m l m b e r of d i f f e r e n t elem e n t s of t h e skeleton a n d t h e k i n d od d a m a g e to t h e bones. S u c h studies will also s h e d m o r e light on t h e problems of b a t palaeoecology a n d t h e evolution of t h e i r a d a p t a t i o n s .
REFERENCES ANTHONY E.L.P. 1990 - Age determination in bats. In Ku~z T. E. (ed.) : Ecological and behavorial methods for the study of bads. Smithsonian Institution Press, Washington : 47-58. ANDREWS P. 1990 - Owls, caves and fossils. Natural History Museum Publications, London : VIII + 231 p. AULAGNIER S. 1989 - Les chauves-souris (Chiroptera) dans le r~gime alimentaire des rapaces nocturnes (Strigiformes) au Maroc. In HANAK V., HORACEKJ., GAISLER J. (eds.) : European bat research 1987. Charles University Press, Praha : 457-463. BAUER tC 1956 - Schleiereule (Tyto alba Scop.) als Fledermausj~iger. Journal ffir Ornithologie, 97 : 335340. BOCHENSKI Z. Jun. 1990 - The food of suburban Tawny Owls on the background of birds and mammals occuring in the hunting territory. Acta zoologica cracoviensia, 33 : 149-171. CAJS L. 1963 - Investigations on the composition of food of several species of owls [Polish]. Zeszyty nauk. Uniw. A. Mickiewicza, Biol., 4 : 1-20. CZARNECKI Z., GRUSZCZYNSKIJ. & SMOLENSKAE. 1955 Investigations on the composition of the food consumed by the Barn Owl (Tyto alba guttata). [Polish, English summary]. Prace Kom. Biol. Pozn. Tow. Przyj. Nauk, 16 : 150-189. GAISLER J. 1966 - A tentative ecological classification of colonies of the European bats. Lynx, s. n., 6 : 35-39. GILLETTE D.S. & KIMBROUGHJ.D. 1970 - Chiropteran mortality. In SLAUGHTER B.H. & WALTON D.W. (eds.) : About bats. Southern Methodist University Press, Dallas : 262-283. HABERSETZER J. & STORCH G. 1989 - Ecology and echolocation of the Eocene Messsel bats. In HANAK V., HORACEKJ. & GAISLER J. (eds.) : European bat research 1987. Charles University Press, Praha : 213-233. HERRERA C. 1973 - Regimen alimentacio de Tylo alba en Espafia Sud occidental. Ardeola, 19 : 359-394. ILJIN V.J. 1989 - Hibernation of bats in the foreststeppe region of the right-bank Povolzhie and their native enemies. In HANAK V., HORACEKJ. & GAISLER J. (eds.) : European bat research 1987. Charles University Press, Praha : 495-497. JAMES P. & HAYNE A. 1963 - Sparrow hawk preys on Mexican free-tailed bat at Falcon Reservoir. Journal of Mammalogy, 44 : 574. JhNOSSY D. & SCHMIDT E. 1970 - Die Nahrtmg des Uhus (Bubo bubo) : Regionale und erdzeitliche ~mderungen. Bonner zoologie Be#rage, 21 : 25-51. KOVES E.O. & SCHMIDT E. 1964 - Angaben zur Kenntniss der Kleins~iugerfauna in der Umgebung -
256 von T o r n y o s n e m e t i (nach GewSlluntersuchungen). Vertebrata hungarica, 6 : 97-108. KOWALSKI IC 1956 - Insectivores, b a t s a n d rodents from t h e E a r l y Pleistocene bone breccia of Podlesice n e a r Kroczyce (Poland). Acta palaeontologica polonica, 1 : 331-394. KOWALSKI M. & LESINSKI G. 1990 - The food of Towny Owl (Strix aluco L.) from n e a r a b a t cave in Poland. Bonner zoologie Beitrage., 41 : 23-26. KRZANOWSKI A. 1973 - N u m e r i c a l comparison of Vesp e r t i l i o n i d a e a n d Rhinolophidae ( C h i r o p t e r a : Maremafia) in t h e owl pellets. Acta zoologica cracoviensia, 18 : 133-140. KULCZYCKI A. 1964 - S t u d y on t h e m a k e up of the diet of owls from t h e N i s k i Beskid Mts. [Polish, English sllmmary]. Acta zoologica cracoviensia, 9 : 529-559. LESINSKI G. 1989 - B a t s (Chiroptera) in t h e food of t h e B a r n owl, Tyto alba (Scop.) on t h e W i e l u n U p l a n d . [Polish, E n g l i s h s u m m a r y ] . Przeglad zoologiczny, 33: 129-135. LESmSKI G. & ROMANOWSKI J. 1988 - M a r t e n s h u n t bats. [Polish]. W s z e c h w i a t , 89 : 210. LESNE L. & THEVENOT M. 1981 - C o n t r i b u t i o n ~ l'~tude du r6gime a l i m e n t a i r e du hibou g r a n d duc Bubo bubo ascalophus d u Maroc. Bulletin de l'Institut des Sciences de Rabat, 5 : 167-177. MARZ R. 1954 - "Samler" W a l d k a u z . Beitrage zur Vogelkunde, 4 : 7-34. NIKODEM Z. 1982 - M a t e r i a l s to t h e b a t f a u n a (Chiroptera) of L u b l i n region ( s o u t h - e a s t e r n Poland) [Polish, E n g l i s h s u m m a r y ] . Przeglad zoologiczny, 26: 197-205. NOWOSAD A. & SALATA-PILACINSKAB. 1987 - B a t s (Chiroptera) in t h e food of the B a r n Owl, Tyto alba guttata (C. L. Brehm, 1831) [Polish, E n g l i s h summary]. Przeglad zoologiczny, 31 : 221-230. OBUCH J. 1992 - T a w n y owl (Strix aluco) p r e y i n g on bats. In HORACEK J. & VOHRALIK V. (eds.) : P r a g u e studies in m a m m a i o g y . Charles University Press, Praha : 119-121.
RICHTER G. & STORCH G. 1980 - Beitr~ige zur Ernahrungsbiologie eoz~,ner Flederm~iuse aus d e r "Grube Messel". Natur und Museum, 110 : 353-367. RUPRECHT A.L. 1979 - Food of t h e B a r n Owl, Tyto alba guttata C. L. Br. from Kujawy. Acta ornithologica, 1 6 : 493-511. RUPRECHT A.L. 1990 - B a t s (Chiroptera) in the food of owls in t h e N a d n o t e c k a Forest. [Polish, E n g l i s h s u m m a r y ] . Przeglad zoologiczny, 34 : 349-358. RUPRECHT A.L. & SZWAGRZAKA. 1987 - .Z.ur Ern~_hrung d e r E u l e n des Bialowieza-Urwaldes. Okol. V6gel. 9 : 89-96. SCHMIDT E. • TOPAL G. 1971 - Flederm~iuse in Eulengewbllen aus U n g a r n . [Hungarian, G e r m a n s u m m a ry]. Vertebrata hungarica, 12 : 93-102. SEVILLA P. 1988 - Estudio paleontol6gico de los QuirSpteros del C u a t e r n a r i o espafiol. Paleontologia i evolucio, 22 : 113-233. SEVILLA P. 1989 - Q u a t e r n a r y f a u n a of b a t s in S p a i n : palaeoecologic a n d biogeographic interest. In HANAK V., HORACEK J. & GAISLER J. (eds.) : E u r o p e a n b a t r e s e a r c h 1987. Charles University Press, Praha : 349-355. SEVILLA P. 1990 - Rhinolophoidea (Chiroptera, M a m malia) from t h e u p p e r Oligocene of C a r r a s c o s a del C a m p o (Central Spain). Geobios, 23 : 173-188. SIGI~ B. & LEGENDRE S. 1982 - L'histoire des peuplem e n t s de chiropt~res d u b a s s i n m 4 d i t e r r a n 6 e n : app o r t compar~ des r e m p l i s s a g e s k a r s t i q u e s et des d4p6ts fiuviolacustres. Mdmoire Biosp~ldologie, 10 : 209-255. WOLOSZYN B. W. 1987 - Pliocene a n d Pleistocene b a t s of Poland. Acta palaeontologica polonica, 32 : 207325.
K. K O W A L S K I
Institute of Systematics and Evolution of Animals Polish Academy of Sciences Slawkowska 17 31-016 Krakow, Poland
KAZIMIERZ KOWALSKI KOWALSKI K_ 1995. Taphonomy of bats (Chiroptera). [Taphonomie de chauves-souris (Chiroptera)]. GEOBIOS, M.S. 18 : 251-256.
ABSTRACT Fossil localities containing remains of bats represent usually either fluvio-limnic or karstic sediments. The factors responsible for the accumulation of bones in these two types of localities may be different. Data on ecology and mortality of these animals accumulated by zoologists are necessary to understand the taphonomy of fossil bat localities. A review of such data, espcially those concerning the role of predators is given. KEY-WORDS : CHIROPTERA,TAPHONOMY,PREDATION,PALEOECOLOGY,
RI~SUMI~ Les faunes fossiles de chauves-souris se trouvent g4n6ralement dans les s6diments soit fluvio-lacustres, soit karstiques. Les facteurs responsables de l'accumulation des ossements dans ces deux types de sites peuvent ~tre diff6rents. Pour l'analyse de la taphonomie de localit4s de chauves-souris fossiles, les donn6es sur l'6cologie et surtout la mortalit6 de ces animaux accumul4es par les zoologistes sont indispensables. La revue de ces donn4es, surtout celles qui concernent le rSle de pr6dateurs, est pr6sent4e. MOTS-CL]~S : CHIROPTERA, TAPHONOMIE,PRI~DATION,PALI~OI~COLOGIE.
The number of studies concerning fossil bats has grown rapidly in the last few years. Nearly all are devoted to systematics and evolution, only a few refer to palaeoecology (e. g. Richter & Storch 1980, Sevilla 1988, 1989) and even less attention has been paid to the taphonomy of these animals. A paper by Sig4 & Legendre (1982) is an exception and it stresses the differences between the localities of fossil bats in fluvio-limnic sediments and those in sediments of karstic hollows. They concluded t h a t the taxonomic composition of the taphocoenoses of bats in these two types of sediments is different. Moreover, the remains in water deposits are scarce and usually of very fragm e n t a r y n a t u r e (although exceptionally represented by entire skeletons), whereas materials originating from k a r s t localities are as a rule numerous, well preserved and contain both skulls and postcranial bones in proportions similar to n a t u r a l ones.
Recent bat species m a y be divided into those which shelter in caves and rock fissures and those hiding mainly in tree hollows. This division is, however, not absolute. Members of some species use caves as hibernacula and tree hollows as roosts in the day time. Typical "forest" species m a y sporadically visit caves (Gaisler 1966). Finally, it must be noted t h a t even typical "cave" species h u n t insects in various habitats, including forests and, quite often, over bodies of water. Therefore, though some differences in composition and preservation of bats between karst and fluvio-limnic sediments ,are to be expected, numerous species m a y be common to both of fossil localities.
Zoological investigations, usually u n k n o w n to paleontologists, yielded m a n y interesting data
Knowledge of the factors influencing the mortality of bats would be useful for understanding
which can be used for a better u n d e r s t a n d i n g of the type of preservation of bats in their fossil assemblages, as well as of the qualitative and quantitative compositions of such assemblages.
252 of the composition of the bat fauna in different types of sites (Gilette and Kimbrough 1970). Our information in this respect is still very limited. It is well known that the life-span of bats is generally longer t h a n it is in other small m~mmals of similar size. The turnover of a population of bats is therefore several times slower than that of rodents and the n u m b e r of carcasses available for fossilisation smaller. This is one of the reasons w h y bats are usually rare as fossils. There are no quantitative studies on the share of different factors in b a t mortality. These factors are as follows : climatic phenomena, diseases, predators and accidents in flight. In temperate regions cold w e a t h e r is probably the most important factor controlling population size. Young a~imals are particularly endangered by unusually long winters and winter colonies in arboreal hibernacula sometimes freeze to death. Also accidents in flight, some connected with weather conditions (storms, heavy rainfall, etc.), m a y be responsible for the death of bats ; mass mortality in colonies m a y be the result of epidemics (Gilette & Kimbrough 1970). A particular type of preservation of bat remains in limnic sediments is represented by nearly complete skeletons found in anatomic order. The most famous locality with such specimens is Messel in Germany. There the sediments of an Eocene lake contain a rich vertebrate fauna, with Chiroptera as the dominant group (Richter & Storch 1980, Habersetzer & Storch 1989). The bats, belonging to 7 species, were in good condition before death, fragments of insects being sometimes recognizable in their stomachs. The preserved individuals are mainly adult, very few are young. No traces of predators have been discovered. Probably the bats were flying over a volcano lake and perished during periodic eruptions of carbon dioxide. Anoxic conditions at the bottom of the lake favoured the preservation of entire specimens. Other, more typical remains of bats preserved in fluvio-limnic sediments are isolated teeth or fragments of bones, among similar specimens belonging to other m~mma]Jan groups. Before deposition they were usually transported by water. In the Oligocene locality Carrascosa del Campo in Spain, Sevilla (1990) discovered remains of the genera Hipposideros, Rhinolophus and Megaderma in fluviatile sediments. These taxa are usually connected with caves and their fossils have hitherto been found together in karst localities. Sevilla is of the opinion that these remains, composed of numerous isolated teeth and fragments of mandibles, accumulated in karstic sediments and were later transported and redeposited by water.
Other of bat remains in the water-deposited sediments m a y be bones of these animals originating from the scat of predators. In karst localities (sediments of caves and fissures) massive accumulations of b a t remains are quite common. As a rule they are very well preserved and contain entire skulls and postcranial bones, although rarely in anatomic order. This type of preservation is exemplified by the Early Pliocene locality Podlesice in Poland where thousands of entire skulls with undamaged brain cases have been found (Kowalski 1956, Woloszyn 1987). Long postcranial bones are sometimes accumulated with their long axes extending in the same direction, this material being sorted by slowly flowing or dripping water, resulting in minimum d~mage to the bones. Today such accumulations of skeletons can be seen under winter colonies of cave bats. Dead and more or less disintegrated bats are common on the walls or floors of caves which are used as hibernacula. They derive from adult or subadult individuals. It is less likely that skeletons from s u m m e r bat colonies in caves should be preserved. The floor under such colonies is usually covered by guano, in which the remains of vertebrates (including bats) become totally dissolved. In karst sediments, particularly those deposited near the entrances of caves or in vertical wells and fissures, the remains of small vertebrates, especially of m~mmals, are very common. There is no doubt as to their taking rise from the food of avian and m~mmalian predators, of owls in particular. The localities of fossil bats in caves, in which these animals are preserved among other small vertebrates, m a y originate from the scat of predators. Many carnivores include bats in their diet when these are available. Known cases of such predation are generally restricted to the birth and nursery season and concern mainly young bats which have fallen to the floor from their colonies. There seem to be no predators as a group that consistently make bats their habitual prey, but there are individual predators whose diet consists regularly of bats (Gilette & Kimbrough 1970). The enemies of bats include snakes and sometimes other reptiles and amphibians, mainly in equatorial regions. Reptiles and amphibians dissolve bones of their prey during digestion and cannot contribute to the accumulations of bat remains. Mammalian carnivores sporadically h u n t bats, especially those living in large colonies in caves. The opportunistic killing of bats by opossums and
253 Australian carnivorous marsupials, shrews, p r i m a t e s , other bats and rodents can only exceptionally contribute to the accumulation of bat bones. In Povolshie in Russia, Iljin (1989) noted the regular presence of bat bones in the droppings of foxes (Vulpes vulpes), the latter hunting bats hibernating in man-made underground tunnels. In Nietoperek in Poland, Lesinski & Romanowski (1988) discovered excrements of the marten (Martes foina) in which the remains of bats constituted 81% of the total mass of remains.
best known owl species in Europe, Tyro alba and Strix aluco, bats constitute less t h a n 1% of all vertebrate individuals eaten (Tables 1-2). In many collections of owl pellets studied, no b a t remains have been noted : such data have not; been included in the tables. The actual percentage of bats in the food of these owls is therefore probably lower. The percentage of b a t remains depends in the first place on the presence of individual owls specializing in bat hunting.
The most important predators of bats are birds. Diurnal birds of prey, mainly falcons and hawks, have been observed hunting bats, usually at dawn or dusk. The objects of these attacks were mainly colonial species during their emergence and morning return (James & Hayne 1963). There are no published data on the effectiveness of such attacks, b u t these birds are not likely accumulators of b a t bones because they become more or less digested in their stomachs.
The data on the share of bats in the diet of particular owl species are not directly comparable b u t the genera] impression is that is is different. This share seems to be the highest in Strix aluco where it is 0.22 - 21.88% (m = 2.66) of the minimum number of individual (MNI) of vertebrates identified in pellets and 0.55 - 23.91% (m = 5.58) of the MNI of m~mmals. In Tyto alba it amounts to 0.12 - 54.74% (m = 0.35%) of vertebrates and 0.14 55.32% (m = 0.60) of mammals.
More attention has been devoted to the hunting of bats by owls. No owl species takes bats as a regular diet component b u t within species are individuals which specialize in attacking Chiroptera (Scbmidt & Topal 1971 ; Ruprecht 1979a, b, 1990 ; Nowosad & Salata-Pilacinska 1987 ; Lesinski 1989 ; Obuch 1992). The proportion of bats in the food of owls is u s u a l y negligible. In the two
In the food remains of Bubo bubo in Europe, the number of bats is insignificant (Jgnossy and Schmidt 1970). In Morocco, however, according to Lesne & Thevenot (1981) bats constituted 1.04% of the MNI of vertebrates eaten by Bubo b. ascalophus. The majority of the collections of pellets deposited by this species in other regions did not contain any bat remains.
-
MNI of bats
Vertebrata % of MNI bats
Mammalia % of i MNI bats
4
480
0.34
278
1.45
4 localities, forest area
13
_
_
1,711
0.76
numerous localities, forest area
_
_
21.88
389
23.91
at the cave entrance
1,344
0.22
547
0.55
1 suburban locality
10
267
3.75
223
4.48
numerous localities, submontain area
7
2,668
0.26
_
_
LOCALITY
AUTHOR
Bialowieza, N. Poland
Ruprecht & Szwagrzak1987
Nadnotecka Puszcza, N. Poland
Ruprecht 1990
Central Poland
Nowosad & Salata-Pilacid'ska 1987
87
Szachownica, Poland
Kowalski & Lesir~ski 1990
93
425
Krak6w, S. Poland
Bocheriski 1990
3
Beskid Niski, S. Poland
Kulczycki 1964
Sachsen, Germany
M&rz 1954
SIovakia
Obuch 1992
14,269 0.61
847 20,088 4.22 15,782 5.37
REMARKS
38 localities, different environments
31 localities 5 localities at cave entrances
Table 1 - The p r o p o r t i o n of b a t s a m o n g food r e m a i n s of S t r i x a l u e o in Europe. MNI = M i n i m u m n u m b e r of individuals. Porportion de chauves-souris p a r m i les restes de nourriture S t r i x a l u v o en Europe. M N I =nombre minimal d'individus.
254
MNI LOCALITY
AUTHOR
REMARKS
MNI
MNI
%of bats
52
95
54.74
94
55.32
1 locality
Cajs 1963
10
4,795
0.21 4?662
0.21
collection from 19 localities
Beskid Niski, Poland
Kulczycki 1964
15
3,326
0.45 3?2999 0.45
Poznan, N. Poland
Czarnecki et aL 1955
28
13,628 0.21 13,014 0.22i
Lublin, SE Poland
Nikodem 1982
137 64,375 0.21
_
_
several localities, in buildings
Nadnotecka Primeval Forest, NW Poland
Ruprecht 1990
26
21,036 0.12
_
_
forest
Central Poland
Nowosad, Salata-Pilacir{ska 1987
87
14,265 0.61
_
_
38 localities, in church towers
Balowieza
Ruprecht, Szwagrzak 1987
3
2,156
2,100
0.14
9localities
Kujawy, C. Poland
Ruprecht 1979
46
16,944] 0.27 13,394 0.34
9localities
Cabra, SW Spain
Herrera 1973
133
9,329
1.43
8,449
1 locality
SW Spain
Herrera 1973
8
4,827
0.17
4,441 0.18
Przemy~l, Poland
Bauer 1956
Mammalia
%of bats
G0ssig, Austria
of bats
Vertebrata
0.14
1.57
several localities 14localities
23 localities in SW Spain (exc. Cabra)
Table 2 - The proportion of bats among the food remains of Tyto alba in Europe. MNI = Minimum number of individuals. Porportion de chauves-souris parmi les restes de nourriture Tyro alba en Europe. MNI =nombre minimal d~ndividus. The differences in the role of bats as food for particular individuals of owls have already been mentioned. In Gtissig in Austria Bauer (1956) found an accumulation of pellets deposited by Tyro alba in a loft inhabited also by a big colony of bats (mainly Myotis myotis and Miniopterus schreibersi). 54.74% of the MNI of vertebrates in these pellets were bats belonging to the species present in the neighbouring colony. Kowalski & Lesinski (1990) studied the pellets of Strix aluco found in the entrance hall of Szachownica Cave in Poland and under the trees outside the entrance : bats constituted 21.88% of al] individuals of vertebrates. In Slovakia bats were found to make up 4.22% of the MNI of vertebrates in the pellets collected at 5 roosts of owls of the same species, situated at the entrances of caves (Obuch 1922). All the indi-
viduals of Strix aluco studied by Obuch regularly h u n t e d bats. In the majority of cases the remains of bats in the food of owls are so scarce t h a t it is evident t h a t the consumption of these animals was accidental and did not result from the definite food preferences of a particular individual. Some species of bats are more numerous in the food remains of owls t h a n others. For example in Poland (Nowosad & Sata-Pilacinska 1987, Ruprecht 1990) the most frequently t a k e n bats are : Eptesicus serotinus, Nyctalus noctula and Plecotus (P. auritus and P. austriacus). Scbmidt & Topal (1971) in H u n g a r y also noted t h a t Eptesicus serotinus and Nyctalus noctula top on the list of bats hunted by owls. Knowledge of the population density of bats is unfortunately so limited t h a t it is impossible to decide wheter this is due to the
255 h i g h e r n u m b e r s of i n d i v i d u a l s of t h e s e p a r t i c u l a r p r e y species or to t h e selectivity of p r e d a t o r s . K r z a n o w s k i (1973) a n a l y z e d t h e s h a r e of diff e r e n t f~milies of bats in t h e food of owls a n d c a m e to t h e conclusion t h a t t h e Rb2nolophidae are u n d e r - r e p r e s e n t e d , c o m p a r e d w i t h t h e Vesp e r t i l i o n i d a e . H e explains it b y a q u i c k e r escape r e a c t i o n ability of h o r s e - s h o e bats. A u l a g n i e r (1989) holds a s i m i l a r opinion. T h e r e are no published d a t a on t h e existence of p r e f e r e n c e for part i c u l a r species of c h i o p t e r a n p r e y in p a r t i c u l a r species of owls : a n o p p o r t u n i s t i c a p p r o a c h seems to be domirlant. O n t h e o t h e r h a n d t h e r e are significant geographical differences in p e r c e n t a g e s of b a t s in t h e owls' food (see tables 1-2) a n d in t h e specific composition of b a t species eaten. T h e y are e v e n evid e n t in s u c h a r e l a t i v e l y u n i f o r m t e r r a i n as t h a t of P o l a n d ( R u p r e c h t 1990). T h e selectivity of owls would be b e t t e r und e r s t o o d ff t h e i r m e t h o d s of h u n t i n g bats w e r e b e t t e r k n o w n . H a r d l y a n y observations are available ; some a u t h o r s suppose t h a t owls c a p t u r e b a t s in flight, p e r h a p s m a i n l y d u r i n g seasonal migrations. D e t e r m i n a t i o n of t h e age of c a p t u r e d bats w o u l d be of some i m p o r t a n c e . Y o u n g b a t s are b o r n w i t h m o r e or less developped deciduous t e e t h w h i c h are g e n e r a l l y r e p l a c e d b y p e r m a n e n t t e e t h b y t h e t i m e t h e y can fly a n d feed i n d e p e n d e n t l y (Anthon y 1990). S u c h studies h a v e not b e e n conducted in t h e case of bats, t h e r e f o r e we are u n a b l e to decide w h e t e r t h e fossil bones o r i g i n a t e d from t h e scat of p r e d a t o r s or not. B y a n a l o g y w i t h o t h e r small m a m m a l s , we can o n l y suppose t h a t t h e p r e s e n c e of u n d a m a g e d b r a i n cases excludes t h e scatological origin of t h e skulls. T h e s e p a r t s of skulls are u s u a l l y t h e first to be d e s t r o y e d b y c h e w i n g a n d digestion. P r o b a b l y p r e d a t o r s do not p l a y such a d o m i n a n t role in t h e a c c u m u l a t i o n of b a t r e m a i n s as in t h e case of o t h e r orders of small m a m m a l s . T h e y m a y n e v e r t h e l e s s be significant in t h e a c c u m u l a t i o n of c h i r o p t e r a n r e m a i n s in fluvio-lacustrine sedim e n t s a n d in k a r s t i c s e d i m e n t s in which b a t bones are m i x e d w i t h t h o s e of r o d e n t s a n d insectivores. F u r t h e r zoological s t u d i e s ( p a r t i c u l a r l y t h o s e concerning t h e m o r t a l i t y of bats) are n e e d e d to increase o u r k n o w l e d g e of t h e t a p h o n o m y of fossil bat f a u n a s . In i n v e s t i g a t i o n s of fossil b a t localities it s h o u l d be obligatory to r e g i s t e r t h e n u m -
be÷ of individuals of p a r t i c u l a r species, t h e age of individual specimens, t h e m l m b e r of d i f f e r e n t elem e n t s of t h e skeleton a n d t h e k i n d od d a m a g e to t h e bones. S u c h studies will also s h e d m o r e light on t h e problems of b a t palaeoecology a n d t h e evolution of t h e i r a d a p t a t i o n s .
REFERENCES ANTHONY E.L.P. 1990 - Age determination in bats. In Ku~z T. E. (ed.) : Ecological and behavorial methods for the study of bads. Smithsonian Institution Press, Washington : 47-58. ANDREWS P. 1990 - Owls, caves and fossils. Natural History Museum Publications, London : VIII + 231 p. AULAGNIER S. 1989 - Les chauves-souris (Chiroptera) dans le r~gime alimentaire des rapaces nocturnes (Strigiformes) au Maroc. In HANAK V., HORACEKJ., GAISLER J. (eds.) : European bat research 1987. Charles University Press, Praha : 457-463. BAUER tC 1956 - Schleiereule (Tyto alba Scop.) als Fledermausj~iger. Journal ffir Ornithologie, 97 : 335340. BOCHENSKI Z. Jun. 1990 - The food of suburban Tawny Owls on the background of birds and mammals occuring in the hunting territory. Acta zoologica cracoviensia, 33 : 149-171. CAJS L. 1963 - Investigations on the composition of food of several species of owls [Polish]. Zeszyty nauk. Uniw. A. Mickiewicza, Biol., 4 : 1-20. CZARNECKI Z., GRUSZCZYNSKIJ. & SMOLENSKAE. 1955 Investigations on the composition of the food consumed by the Barn Owl (Tyto alba guttata). [Polish, English summary]. Prace Kom. Biol. Pozn. Tow. Przyj. Nauk, 16 : 150-189. GAISLER J. 1966 - A tentative ecological classification of colonies of the European bats. Lynx, s. n., 6 : 35-39. GILLETTE D.S. & KIMBROUGHJ.D. 1970 - Chiropteran mortality. In SLAUGHTER B.H. & WALTON D.W. (eds.) : About bats. Southern Methodist University Press, Dallas : 262-283. HABERSETZER J. & STORCH G. 1989 - Ecology and echolocation of the Eocene Messsel bats. In HANAK V., HORACEKJ. & GAISLER J. (eds.) : European bat research 1987. Charles University Press, Praha : 213-233. HERRERA C. 1973 - Regimen alimentacio de Tylo alba en Espafia Sud occidental. Ardeola, 19 : 359-394. ILJIN V.J. 1989 - Hibernation of bats in the foreststeppe region of the right-bank Povolzhie and their native enemies. In HANAK V., HORACEKJ. & GAISLER J. (eds.) : European bat research 1987. Charles University Press, Praha : 495-497. JAMES P. & HAYNE A. 1963 - Sparrow hawk preys on Mexican free-tailed bat at Falcon Reservoir. Journal of Mammalogy, 44 : 574. JhNOSSY D. & SCHMIDT E. 1970 - Die Nahrtmg des Uhus (Bubo bubo) : Regionale und erdzeitliche ~mderungen. Bonner zoologie Be#rage, 21 : 25-51. KOVES E.O. & SCHMIDT E. 1964 - Angaben zur Kenntniss der Kleins~iugerfauna in der Umgebung -
256 von T o r n y o s n e m e t i (nach GewSlluntersuchungen). Vertebrata hungarica, 6 : 97-108. KOWALSKI IC 1956 - Insectivores, b a t s a n d rodents from t h e E a r l y Pleistocene bone breccia of Podlesice n e a r Kroczyce (Poland). Acta palaeontologica polonica, 1 : 331-394. KOWALSKI M. & LESINSKI G. 1990 - The food of Towny Owl (Strix aluco L.) from n e a r a b a t cave in Poland. Bonner zoologie Beitrage., 41 : 23-26. KRZANOWSKI A. 1973 - N u m e r i c a l comparison of Vesp e r t i l i o n i d a e a n d Rhinolophidae ( C h i r o p t e r a : Maremafia) in t h e owl pellets. Acta zoologica cracoviensia, 18 : 133-140. KULCZYCKI A. 1964 - S t u d y on t h e m a k e up of the diet of owls from t h e N i s k i Beskid Mts. [Polish, English sllmmary]. Acta zoologica cracoviensia, 9 : 529-559. LESINSKI G. 1989 - B a t s (Chiroptera) in t h e food of t h e B a r n owl, Tyto alba (Scop.) on t h e W i e l u n U p l a n d . [Polish, E n g l i s h s u m m a r y ] . Przeglad zoologiczny, 33: 129-135. LESmSKI G. & ROMANOWSKI J. 1988 - M a r t e n s h u n t bats. [Polish]. W s z e c h w i a t , 89 : 210. LESNE L. & THEVENOT M. 1981 - C o n t r i b u t i o n ~ l'~tude du r6gime a l i m e n t a i r e du hibou g r a n d duc Bubo bubo ascalophus d u Maroc. Bulletin de l'Institut des Sciences de Rabat, 5 : 167-177. MARZ R. 1954 - "Samler" W a l d k a u z . Beitrage zur Vogelkunde, 4 : 7-34. NIKODEM Z. 1982 - M a t e r i a l s to t h e b a t f a u n a (Chiroptera) of L u b l i n region ( s o u t h - e a s t e r n Poland) [Polish, E n g l i s h s u m m a r y ] . Przeglad zoologiczny, 26: 197-205. NOWOSAD A. & SALATA-PILACINSKAB. 1987 - B a t s (Chiroptera) in t h e food of the B a r n Owl, Tyto alba guttata (C. L. Brehm, 1831) [Polish, E n g l i s h summary]. Przeglad zoologiczny, 31 : 221-230. OBUCH J. 1992 - T a w n y owl (Strix aluco) p r e y i n g on bats. In HORACEK J. & VOHRALIK V. (eds.) : P r a g u e studies in m a m m a i o g y . Charles University Press, Praha : 119-121.
RICHTER G. & STORCH G. 1980 - Beitr~ige zur Ernahrungsbiologie eoz~,ner Flederm~iuse aus d e r "Grube Messel". Natur und Museum, 110 : 353-367. RUPRECHT A.L. 1979 - Food of t h e B a r n Owl, Tyto alba guttata C. L. Br. from Kujawy. Acta ornithologica, 1 6 : 493-511. RUPRECHT A.L. 1990 - B a t s (Chiroptera) in the food of owls in t h e N a d n o t e c k a Forest. [Polish, E n g l i s h s u m m a r y ] . Przeglad zoologiczny, 34 : 349-358. RUPRECHT A.L. & SZWAGRZAKA. 1987 - .Z.ur Ern~_hrung d e r E u l e n des Bialowieza-Urwaldes. Okol. V6gel. 9 : 89-96. SCHMIDT E. • TOPAL G. 1971 - Flederm~iuse in Eulengewbllen aus U n g a r n . [Hungarian, G e r m a n s u m m a ry]. Vertebrata hungarica, 12 : 93-102. SEVILLA P. 1988 - Estudio paleontol6gico de los QuirSpteros del C u a t e r n a r i o espafiol. Paleontologia i evolucio, 22 : 113-233. SEVILLA P. 1989 - Q u a t e r n a r y f a u n a of b a t s in S p a i n : palaeoecologic a n d biogeographic interest. In HANAK V., HORACEK J. & GAISLER J. (eds.) : E u r o p e a n b a t r e s e a r c h 1987. Charles University Press, Praha : 349-355. SEVILLA P. 1990 - Rhinolophoidea (Chiroptera, M a m malia) from t h e u p p e r Oligocene of C a r r a s c o s a del C a m p o (Central Spain). Geobios, 23 : 173-188. SIGI~ B. & LEGENDRE S. 1982 - L'histoire des peuplem e n t s de chiropt~res d u b a s s i n m 4 d i t e r r a n 6 e n : app o r t compar~ des r e m p l i s s a g e s k a r s t i q u e s et des d4p6ts fiuviolacustres. Mdmoire Biosp~ldologie, 10 : 209-255. WOLOSZYN B. W. 1987 - Pliocene a n d Pleistocene b a t s of Poland. Acta palaeontologica polonica, 32 : 207325.
K. K O W A L S K I
Institute of Systematics and Evolution of Animals Polish Academy of Sciences Slawkowska 17 31-016 Krakow, Poland