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The otter Lutra lutra in Albania
Biological Conservation 36 (1986) 375-383
The Otter Lufra lutra in Albania
Claudio Prigioni, Giuseppe Bogliani & FrancescoBarbieri Dipartimento di Biologia Animale, Universita di Pavia, Piazza Botta 9, 27100 Pavia, Italy
ABSTRACT During a survey in Albania we found signs of otters at 17 (54.8%) of the 31 stations investigated. Otters were widespread in much of the country, and healthy populations were localised in rivers and marshes in the north-west and in the south. Average sprainting activity was I.7 positive sites per 200 m and 3.6 spraints per 200 m. Frogs, probably Rana ridibunda, as well as fish, appeared to be important prey for otters. In the coastal plains, several rivers were grossly polluted and the growing agricultural and industrial development may endanger the survival of otters.
INTRODUCTION The otter Lutra Zutru has declined substantially in many European countries (Reuther & Festetics, 1980). Recent field surveys, however, have recorded that the species is still widespread in the south of its range, and particularly in Portugal and Greece (Macdonald & Mason, 1982a,b), in Tunisia (Macdonald & kason, 1983a), in Spain (Elliot, 1983),and in Yugoslavia (Liles & Jenkins, 1984).No data are available about the status of the otter in Albania. This paper reports the results of a survey in Albania with the intention of increasing knowledge on the distribution of otters within countries in the Mediterranean basin. 375 Biol. Conseru. 0006-3207/86/$03.50 0 ElsevierApplied SciencePublishers Ltd, England, 1986. Printed in Great Britain
376
Claudia
Prigioni.
Giuseppe Bogliani,
Francesco Barbieri
STUDY AREA Albania covers an area of 28 784km2 and has an average population density of 97 kmm2 (range 28-256 people kmm2). Some 76.6% of the territory is mountainous with an average altitude of 708m above sealevel: the highest in Europe. The main plains (200m asl) run along the coasts of the country where large reclaimed areashave been cultivated. Other inland plains also resulted from reclamation (for instance, the Korce’s plain at an altitude of SOOm).The predominant crops in the plains are wheat, maize, vegetables,oats, sunflowers, cotton, tobacco, rice and forage, while olives, vineyards, citrus fruit and orchards are widespread in the lowest hills, which have been terraced for cultivation. Forty per cent of the land is forested, predominantly in the mountainous regions. While traditional agricultural methods are still widely practised, mechanisation is advancing rapidly. Since 1960 organochlorine pesticides, especially Lindane, have been used extensively. Sheepand cattle grazing is widespread. Industry in Albania has developed rapidly over the last twenty years. With the mining of iron, chrome and nickel distributed over most of the country, iron and steel industries have developed especially near Kruje, Elbasan, Shkoder and Kukes. Oil is extracted and refined near Fier. The main rivers of Albania in order of decreasing volumetric flow m3 ( s-l) are the Drin (5800) Vjose (4240) Seman (1800), Shkumbin (1430),Erzen (980) and Mat (740). These rivers, becauseof the irregular precipitation, have a torrential and erosive character and generally have wide, meandering river-beds, but about 400km of rivers have been embanked. In the lowlands, riparian vegetation is very scarceand several river beds are used for gravel extraction. Some rivers (Drin and Mat) have been harnessedfor hydroelectric power. Fifty-five per cent of the arable land is irrigated with waters drawn from the rivers and from hundreds of reservoirs. In the coastal plains the more important rivers were visibly polluted by industrial wastes (e.g. R. Seman by oil). METHODS The survey was carried out between 18 and 27 May 1985 and was concentrated on the Shkumbin catchment and on the rivers, lagoons and marshes in the plain along the coasts of the country. Sites were
The otter in Albania
Fig. 1. Distribution of stations surveyed for signs of otters in Albania.
377
378
Claudio Prigioni. Giuseppe Bogliani, Francesco Barbieri
chosen for easeof access,e.g. at bridges, or where a river runs close to a road, and at each site a minimum distance of 200m was searchedfor signs of otters, namely faeces (spraints) and footprints. Otters were presumed absent from a site when, after a search of 600m or 1 km of bank, no signs had been found. A description of the habitat was made at each site. A sample of spraints was collected from sites distributed throughout the study area, and the spraints were washed through a fine sieve and air-dried for examination. Reliable information on otters killed or sighted in the winter of 1984-85was also collected by interviews with anglers, fisherman and hunters during the survey (Fig. 1, see asterisks). RESULTS A total of 31 sites was surveyed (Fig. 1) and 17 (54.8%) showed signs of otters. Also, three sites on as many small rivers that became dry during summer are considered here since one of them was positive for otters. The greatest percentage of positive sites was recorded within the Shkumbin catchment (83.3%) but the Bistrice catchment also produced good results (75.0% positive). For the other river catchments this calculation is impossible because of an insufficient number of sites surveyed. Signs of the otter were recorded on one stream of only 2m width. The habitat of each site surveyed was classified into three categories (1 = good; 2 = medium; 3 = poor) in relation to its potential for holts or lying-up places. Grade 1 habitat comprised sites with good lying-up zones in the form of dense reed beds, densethickets of plane and oak, caves or rocks; grade 2 habitat contained some scrub or reed offering limited shelter, while grade 3 has no suitable lying-up places. In relation to these categories the percentagesof positive sites were: 100.0% in grade 1 habitat, 62.5% in grade 2, and 15.4% in grade 3. Sixty per cent of the number of positive sites with good habitat was recorded in upland rivers or streams, while all the sites with medium habitat were found in lowland rivers. Of 14 stations where no sign of otters was found, 6 were on major rivers, viz. Vjose, Shkumbin, Seman, Devoll, which showed evident industrial pollution. The densities of the sprainting sites and of the number of spraints recorded at positive sites were standard&d as numbers per 200m (Macdonald & Mason, 1982~).For the calculations
The otter in Albania
379
of the number of otter signs we included spraints and anal secretions only. Over the study area an average of 1.7 marked sites and an average of 3.6 signs were found per 200m. The greatest levels of sprainting activity were recorded on the Mat river with 3.6 sites and 5.8 signs, and on the Bistrice river with 3.3 sites and 7.3 signs, while averageson the Drin and Shkumbin rivers were of O-8sites and O-8signs, and O-7sites and 2.6 signs, respectively. A significant difference (t = 3.7 and t = 3.4; p < 0.05) was recorded only when comparing the number of sprainting sites per 200m between Mat river and Drin river and between Bistrice river and Shkumbin river. The percentage of positive sites and the sprainting activity found in two altitudinal ranges(O-300m and > 300m) were compared, but no significant difference was recorded between them. Spraints were found on different substrata. Of the total of 3 1 spraints, 41.9% were found on large stones or boulders and 28.8% on small stones. Other sprainting sites comprised grass (g-7%), trunks or stumps of trees (g-7%), mud (6.4%) and a drain pipe (3.2%). At a further 3.2% of sites, spraints were found associatedwith scratching in sand. Thus, 67.8% of all spraints were located on stones and boulders. Otters do not seem to favour sprainting sites under bridges, although ledges, boulders or washing stones were available. In upland rivers the visible potential holt sites and lying-up sites were offered by old trees (Hutanus orientalis and Quercus sp.) with well-developed root systems and by fissures in rocks, while in the plains, potential sites were provided by bankside scrub of brambles Rubus agg., Mix spp., Typha sp., Phragmites sp. and Scirpus maritimus. TABLE 1 The Frequency of Occurrence and the Relative Frequency of Prey Items in Thirty-three Otter Spraints from Albania Taxon Salmonid Cyprinid Percid Rana sp. Natrix sp. Crustacea Aauatic insect
Frequency (%)
Relative frequency (%)
12.1 66.6 9-o 39.4 12.1 18.2 18.2
6.9 37.9 5-2 22.4 6.9 10.3 10.3
380
Claudia
Prigioni,
Giuseppe Rogliani,
Francesco Barbieri
Thirty-three spraints collected throughout the study area were analysed for their contents. The results are presentedin Table 1 as frequency of occurrence (percentageof spraints containing a specific taxon) and as relative frequency (percentageof each prey item on the total number of items). Although the sample examined is too small to obtain adequate information on feeding patterns, fish made up 50.0% of the diet with a prevalence of cyprinids, while frogs, probably Rana ridibunda only, are a second prey category, in order of importance. DISCUSSION During the field survey of otters in Albania, we also gatheredinformation on animals killed or sighted during the winter 1984-85. Most of these data were collected from areas that we ourselves were unable to visit becauseof travel restrictions. From this information, together with our own observations, it seems that the speciesis widespread in much of Albania and that healthy populations were localised in the Mat and Bistrice rivers and in the coastal marshes of Shengjin and Lezhe. From our field investigations we found 54.8% of sites to be positive. These results are lower only than those recorded for Ireland, 91.7% (Chapman & Chapman, 1982),Scotland, 73.0% (Green & Green, 1980),Portugal, 70.0% (Macdonald & Mason, 1982a)and Greece, 62.0% (Macdonald & Mason, 1982b).We suggestthat this result depicts the present status of otters in Albania, although it could be influenced by the low sample of sites examined. However, we concentrated our searchin coastal plains where the otter is scarceor absent in large zones and we did not include areas such as the Albanian Alps or the Drin catchment, which are potentially suitable for the otter. In fact, we were told of severalanimals that had been killed on the lower reachesof the Drin and its tributaries. Also, we did not investigate the Prespa lakes, where the otter was recorded on the Greek sides by Macdonald & Mason (19823). We did not find any signs of otters on rivers with evident pollution or with very scarce bankside vegetation, but of five sites where heavy gravel extraction occurred, two were positive. In the coastal plains between Tirane and Vlore, all the main rivers, viz. Erzen, Seman, Shkumbin, Vjose, contained some long reacheswhich were grossly polluted mostly by mine drainage, by iron and steel industries and by oil refineries. In addition, this area is intensively
381
The otter in Albania
cultivated and pesticidesseemto be used widely. Inland serious pollution due to mining and to sugar factories was found on the Devoll river in the Korce plain. Generally the high water pollution was associatedwith a high presenceof Rattus noruegicus.On the lake of Shkrodes, where we classified the habitat as medium, there were no signs of otters, but the specieswas recorded in some little tributaries of the lake and in the neighbouring fisheries. It seemsthat the otter is not present even on the Yugoslav sides of this lake (Liles & Jenkins, 1984). By contrast otters were found, although with a low sprainting activity, in the lake of Ohrid where the habitat was poor. The otter is well known to Albanian anglers, fishermen and hunters and, at those sites we visited, we were able to confirm their reports of otter presence. In Albania the otter is still considered as a fur bearer and it is legally hunted in winter with many individuals being killed each year. Even during the closed season animals are destroyed, especially around commercial fisheries. In the lowest reach of the Mat river, 20 km long, five otters were killed in the winter 1984-85. Some individuals are also caught by fishermen in fyke nets. In order to obtain some indication of the health of otter populations in Albania, we recorded the sprainting activity, calculated as number of sprainting sites per 200m and as numbers of spraints per 200m. Macdonald & Mason (1983c) indicate that this parameter cannot be considered as a measure of population size, because several factors influence recorded levels of marking. It is, however, generally suggested that a high intensity of marking may indicate a high population density (Green & Green, 1981). We found that the level of marking showed intermediate values when compared with those recorded for central Portugal and Spain (Table 2). Bearing in mind that these comparisons can be misleading because of the different modes of sampling, the TABLE
2
Sprainting Activity Recorded in Central Portugal (Macdonald h Mason, 1982a), Spain (Elliot, 1983) and Albania Central Portugal
Average no. of sprainting sites per 200m Average no. of spraints per 200m
34 6.9
Spain
Albania
l-3 2.1
1.7 3.6
382
Claudia Prigioni. GiuseppeBogliani, Francesco Barbieri
TABLE 3 Relative Frequency of Prey Items Found in Spraints Collected in Albania and in Greece (Macdonald & Mason, 19823)
Albania Greece
Fish (%)
Amphibian (%)
Natrix (%)
Cfwtacea (%)
SO.0 56.2
22.4 23.7
6.9 3-7
10-3 11.2
population of otters in Albania seemsto be in a healthy state but not so good as in central Portugal, where one of the best European populations occurs. During the survey we found an abundance of potential prey items for otters at most stations sampled. Besides fish-especially cyprinidsfrogs Rana ridibunda and snakesNatrix tessellatawere widespread and very common. Spraint analysis showed that cyprinids and frogs were the two most important categoriesof food. This information on the diet of otters in Albania agreesvery well with that found in Greece (Table 3) and shows that frogs and snakes are usual prey items of the otter in the south of its range. We did not find any mammal or bird, as recorded in the diet of otters in Greece. In the last 30 years, Albania has undergone a rapid agricultural and industrial development that has involved marked lossesin otter habitat. Major environmental modifications have mostly occurred in the lowlands where the otter has substantially declined. We suggest that the main cause of this decline has been the organic and industrial pollution, much probably due to the increasing use of organochlorine pesticides introduced since 1960.In addition, the destruction of bankside vegetation has been another negative factor, but in rivers with wide beds, otters can find suitable shelter on small islands covered by dense shrubs. Fishing, sheep herding and cattle-grazing do not seem to influence the presenceof otters. However, hunting, although practised by few hunters (some thousands), is an important limiting factor. Nevertheless, the Albanian Government, showing sensitivity to our requests, intends to protect the otter from 1986 onwards, allowing only the control of animals damaging fisheries. Albania holds a fair population of otters and this agreessubstantially with the results obtained in previous surveys in the southern range of the species, except for southern Italy (Macdonald & Mason, 19836). For the conservation of this important population, practical measures
The otter in Albania
983
are needed as soon as possible to avoid the isolation of southern and northern populations. For Greece, Macdonald & Mason (1985) suggestedthe establishment of ‘river parks’ in riparian habitats, these being owned by the State. This solution would be highly suitable for Albania, where private property is absent. ACKNOWLEDGEMENTS We are very grateful to the Albanian Government for the opportunity to carry out this work, to the Faculty of Natural Science of the University of Tirane for the assistanceoffered, to Prof. F. Lamani for the help in fieldwork and to Dr S. M. Macdonald and Dr C. F. Mason for the revision of the manuscript. REFERENCES Chapman, F. J. & Chapman,L. L. (1982).Otter survey of Ireland 1980-81. London, Vincent Wildlife Trust. Elliot, K. M. (1983). The otter (Lutra lutra L.) in Spain. Mammal Rev., 13, 25-34.
Green, J. & Green, R. (1980). Otter survey of Scotland 1977-79. London, Vincent Wildlife Trust. Green, J. & Green, R. (1981).The otter (Lutra lutra L.) in western France. Mammal Rev., 11, 181-7. Liles, G. & Jenkins, L. (1984). A field survey for otters (Lutra lutra) in Yugoslavia. J. Zool. Lond., 202, 282-4. Macdonald, S. M. & Mason, C. F. (1982a). The otter (Lutra lutra) in Central Portugal. Biol. Conserv., 22, 207-15. Macdonald, S. M. dz Mason, C. F. (1982b). Otters in Greece. Oryx, 16, 240-4.
Macdonald, S. M. & Mason, C. F. (1983a). The otter (Lutra lutra) in Tunisia. Mammal Rev., 13, 35-7. Macdonald, S. M. & Mason, C. F. (1983b). The otter (Lutra lutra) in Southern Italy. Biol. Conserv., 25, 95-101. Macdonald, S. M. & Mason, C. F. (1983~). Some factors influencing the distribution of otters (Lutra lutra). Mammal Rev., 13, l-10. Macdonald, S. M. & Mason, C. F. (1985). Otters, their habitat and conservation in Northern Greece. Biol. Conseru., 31, 191-210. Reuther, C. & Festetics, A. (eds) (1980). Der Fischotter in Europa. Verbreitung, Bedrohung, Erhaltung. Oderhaus-Gottingen, Selbstverlag.
The Otter Lufra lutra in Albania
Claudio Prigioni, Giuseppe Bogliani & FrancescoBarbieri Dipartimento di Biologia Animale, Universita di Pavia, Piazza Botta 9, 27100 Pavia, Italy
ABSTRACT During a survey in Albania we found signs of otters at 17 (54.8%) of the 31 stations investigated. Otters were widespread in much of the country, and healthy populations were localised in rivers and marshes in the north-west and in the south. Average sprainting activity was I.7 positive sites per 200 m and 3.6 spraints per 200 m. Frogs, probably Rana ridibunda, as well as fish, appeared to be important prey for otters. In the coastal plains, several rivers were grossly polluted and the growing agricultural and industrial development may endanger the survival of otters.
INTRODUCTION The otter Lutra Zutru has declined substantially in many European countries (Reuther & Festetics, 1980). Recent field surveys, however, have recorded that the species is still widespread in the south of its range, and particularly in Portugal and Greece (Macdonald & Mason, 1982a,b), in Tunisia (Macdonald & kason, 1983a), in Spain (Elliot, 1983),and in Yugoslavia (Liles & Jenkins, 1984).No data are available about the status of the otter in Albania. This paper reports the results of a survey in Albania with the intention of increasing knowledge on the distribution of otters within countries in the Mediterranean basin. 375 Biol. Conseru. 0006-3207/86/$03.50 0 ElsevierApplied SciencePublishers Ltd, England, 1986. Printed in Great Britain
376
Claudia
Prigioni.
Giuseppe Bogliani,
Francesco Barbieri
STUDY AREA Albania covers an area of 28 784km2 and has an average population density of 97 kmm2 (range 28-256 people kmm2). Some 76.6% of the territory is mountainous with an average altitude of 708m above sealevel: the highest in Europe. The main plains (200m asl) run along the coasts of the country where large reclaimed areashave been cultivated. Other inland plains also resulted from reclamation (for instance, the Korce’s plain at an altitude of SOOm).The predominant crops in the plains are wheat, maize, vegetables,oats, sunflowers, cotton, tobacco, rice and forage, while olives, vineyards, citrus fruit and orchards are widespread in the lowest hills, which have been terraced for cultivation. Forty per cent of the land is forested, predominantly in the mountainous regions. While traditional agricultural methods are still widely practised, mechanisation is advancing rapidly. Since 1960 organochlorine pesticides, especially Lindane, have been used extensively. Sheepand cattle grazing is widespread. Industry in Albania has developed rapidly over the last twenty years. With the mining of iron, chrome and nickel distributed over most of the country, iron and steel industries have developed especially near Kruje, Elbasan, Shkoder and Kukes. Oil is extracted and refined near Fier. The main rivers of Albania in order of decreasing volumetric flow m3 ( s-l) are the Drin (5800) Vjose (4240) Seman (1800), Shkumbin (1430),Erzen (980) and Mat (740). These rivers, becauseof the irregular precipitation, have a torrential and erosive character and generally have wide, meandering river-beds, but about 400km of rivers have been embanked. In the lowlands, riparian vegetation is very scarceand several river beds are used for gravel extraction. Some rivers (Drin and Mat) have been harnessedfor hydroelectric power. Fifty-five per cent of the arable land is irrigated with waters drawn from the rivers and from hundreds of reservoirs. In the coastal plains the more important rivers were visibly polluted by industrial wastes (e.g. R. Seman by oil). METHODS The survey was carried out between 18 and 27 May 1985 and was concentrated on the Shkumbin catchment and on the rivers, lagoons and marshes in the plain along the coasts of the country. Sites were
The otter in Albania
Fig. 1. Distribution of stations surveyed for signs of otters in Albania.
377
378
Claudio Prigioni. Giuseppe Bogliani, Francesco Barbieri
chosen for easeof access,e.g. at bridges, or where a river runs close to a road, and at each site a minimum distance of 200m was searchedfor signs of otters, namely faeces (spraints) and footprints. Otters were presumed absent from a site when, after a search of 600m or 1 km of bank, no signs had been found. A description of the habitat was made at each site. A sample of spraints was collected from sites distributed throughout the study area, and the spraints were washed through a fine sieve and air-dried for examination. Reliable information on otters killed or sighted in the winter of 1984-85was also collected by interviews with anglers, fisherman and hunters during the survey (Fig. 1, see asterisks). RESULTS A total of 31 sites was surveyed (Fig. 1) and 17 (54.8%) showed signs of otters. Also, three sites on as many small rivers that became dry during summer are considered here since one of them was positive for otters. The greatest percentage of positive sites was recorded within the Shkumbin catchment (83.3%) but the Bistrice catchment also produced good results (75.0% positive). For the other river catchments this calculation is impossible because of an insufficient number of sites surveyed. Signs of the otter were recorded on one stream of only 2m width. The habitat of each site surveyed was classified into three categories (1 = good; 2 = medium; 3 = poor) in relation to its potential for holts or lying-up places. Grade 1 habitat comprised sites with good lying-up zones in the form of dense reed beds, densethickets of plane and oak, caves or rocks; grade 2 habitat contained some scrub or reed offering limited shelter, while grade 3 has no suitable lying-up places. In relation to these categories the percentagesof positive sites were: 100.0% in grade 1 habitat, 62.5% in grade 2, and 15.4% in grade 3. Sixty per cent of the number of positive sites with good habitat was recorded in upland rivers or streams, while all the sites with medium habitat were found in lowland rivers. Of 14 stations where no sign of otters was found, 6 were on major rivers, viz. Vjose, Shkumbin, Seman, Devoll, which showed evident industrial pollution. The densities of the sprainting sites and of the number of spraints recorded at positive sites were standard&d as numbers per 200m (Macdonald & Mason, 1982~).For the calculations
The otter in Albania
379
of the number of otter signs we included spraints and anal secretions only. Over the study area an average of 1.7 marked sites and an average of 3.6 signs were found per 200m. The greatest levels of sprainting activity were recorded on the Mat river with 3.6 sites and 5.8 signs, and on the Bistrice river with 3.3 sites and 7.3 signs, while averageson the Drin and Shkumbin rivers were of O-8sites and O-8signs, and O-7sites and 2.6 signs, respectively. A significant difference (t = 3.7 and t = 3.4; p < 0.05) was recorded only when comparing the number of sprainting sites per 200m between Mat river and Drin river and between Bistrice river and Shkumbin river. The percentage of positive sites and the sprainting activity found in two altitudinal ranges(O-300m and > 300m) were compared, but no significant difference was recorded between them. Spraints were found on different substrata. Of the total of 3 1 spraints, 41.9% were found on large stones or boulders and 28.8% on small stones. Other sprainting sites comprised grass (g-7%), trunks or stumps of trees (g-7%), mud (6.4%) and a drain pipe (3.2%). At a further 3.2% of sites, spraints were found associatedwith scratching in sand. Thus, 67.8% of all spraints were located on stones and boulders. Otters do not seem to favour sprainting sites under bridges, although ledges, boulders or washing stones were available. In upland rivers the visible potential holt sites and lying-up sites were offered by old trees (Hutanus orientalis and Quercus sp.) with well-developed root systems and by fissures in rocks, while in the plains, potential sites were provided by bankside scrub of brambles Rubus agg., Mix spp., Typha sp., Phragmites sp. and Scirpus maritimus. TABLE 1 The Frequency of Occurrence and the Relative Frequency of Prey Items in Thirty-three Otter Spraints from Albania Taxon Salmonid Cyprinid Percid Rana sp. Natrix sp. Crustacea Aauatic insect
Frequency (%)
Relative frequency (%)
12.1 66.6 9-o 39.4 12.1 18.2 18.2
6.9 37.9 5-2 22.4 6.9 10.3 10.3
380
Claudia
Prigioni,
Giuseppe Rogliani,
Francesco Barbieri
Thirty-three spraints collected throughout the study area were analysed for their contents. The results are presentedin Table 1 as frequency of occurrence (percentageof spraints containing a specific taxon) and as relative frequency (percentageof each prey item on the total number of items). Although the sample examined is too small to obtain adequate information on feeding patterns, fish made up 50.0% of the diet with a prevalence of cyprinids, while frogs, probably Rana ridibunda only, are a second prey category, in order of importance. DISCUSSION During the field survey of otters in Albania, we also gatheredinformation on animals killed or sighted during the winter 1984-85. Most of these data were collected from areas that we ourselves were unable to visit becauseof travel restrictions. From this information, together with our own observations, it seems that the speciesis widespread in much of Albania and that healthy populations were localised in the Mat and Bistrice rivers and in the coastal marshes of Shengjin and Lezhe. From our field investigations we found 54.8% of sites to be positive. These results are lower only than those recorded for Ireland, 91.7% (Chapman & Chapman, 1982),Scotland, 73.0% (Green & Green, 1980),Portugal, 70.0% (Macdonald & Mason, 1982a)and Greece, 62.0% (Macdonald & Mason, 1982b).We suggestthat this result depicts the present status of otters in Albania, although it could be influenced by the low sample of sites examined. However, we concentrated our searchin coastal plains where the otter is scarceor absent in large zones and we did not include areas such as the Albanian Alps or the Drin catchment, which are potentially suitable for the otter. In fact, we were told of severalanimals that had been killed on the lower reachesof the Drin and its tributaries. Also, we did not investigate the Prespa lakes, where the otter was recorded on the Greek sides by Macdonald & Mason (19823). We did not find any signs of otters on rivers with evident pollution or with very scarce bankside vegetation, but of five sites where heavy gravel extraction occurred, two were positive. In the coastal plains between Tirane and Vlore, all the main rivers, viz. Erzen, Seman, Shkumbin, Vjose, contained some long reacheswhich were grossly polluted mostly by mine drainage, by iron and steel industries and by oil refineries. In addition, this area is intensively
381
The otter in Albania
cultivated and pesticidesseemto be used widely. Inland serious pollution due to mining and to sugar factories was found on the Devoll river in the Korce plain. Generally the high water pollution was associatedwith a high presenceof Rattus noruegicus.On the lake of Shkrodes, where we classified the habitat as medium, there were no signs of otters, but the specieswas recorded in some little tributaries of the lake and in the neighbouring fisheries. It seemsthat the otter is not present even on the Yugoslav sides of this lake (Liles & Jenkins, 1984). By contrast otters were found, although with a low sprainting activity, in the lake of Ohrid where the habitat was poor. The otter is well known to Albanian anglers, fishermen and hunters and, at those sites we visited, we were able to confirm their reports of otter presence. In Albania the otter is still considered as a fur bearer and it is legally hunted in winter with many individuals being killed each year. Even during the closed season animals are destroyed, especially around commercial fisheries. In the lowest reach of the Mat river, 20 km long, five otters were killed in the winter 1984-85. Some individuals are also caught by fishermen in fyke nets. In order to obtain some indication of the health of otter populations in Albania, we recorded the sprainting activity, calculated as number of sprainting sites per 200m and as numbers of spraints per 200m. Macdonald & Mason (1983c) indicate that this parameter cannot be considered as a measure of population size, because several factors influence recorded levels of marking. It is, however, generally suggested that a high intensity of marking may indicate a high population density (Green & Green, 1981). We found that the level of marking showed intermediate values when compared with those recorded for central Portugal and Spain (Table 2). Bearing in mind that these comparisons can be misleading because of the different modes of sampling, the TABLE
2
Sprainting Activity Recorded in Central Portugal (Macdonald h Mason, 1982a), Spain (Elliot, 1983) and Albania Central Portugal
Average no. of sprainting sites per 200m Average no. of spraints per 200m
34 6.9
Spain
Albania
l-3 2.1
1.7 3.6
382
Claudia Prigioni. GiuseppeBogliani, Francesco Barbieri
TABLE 3 Relative Frequency of Prey Items Found in Spraints Collected in Albania and in Greece (Macdonald & Mason, 19823)
Albania Greece
Fish (%)
Amphibian (%)
Natrix (%)
Cfwtacea (%)
SO.0 56.2
22.4 23.7
6.9 3-7
10-3 11.2
population of otters in Albania seemsto be in a healthy state but not so good as in central Portugal, where one of the best European populations occurs. During the survey we found an abundance of potential prey items for otters at most stations sampled. Besides fish-especially cyprinidsfrogs Rana ridibunda and snakesNatrix tessellatawere widespread and very common. Spraint analysis showed that cyprinids and frogs were the two most important categoriesof food. This information on the diet of otters in Albania agreesvery well with that found in Greece (Table 3) and shows that frogs and snakes are usual prey items of the otter in the south of its range. We did not find any mammal or bird, as recorded in the diet of otters in Greece. In the last 30 years, Albania has undergone a rapid agricultural and industrial development that has involved marked lossesin otter habitat. Major environmental modifications have mostly occurred in the lowlands where the otter has substantially declined. We suggest that the main cause of this decline has been the organic and industrial pollution, much probably due to the increasing use of organochlorine pesticides introduced since 1960.In addition, the destruction of bankside vegetation has been another negative factor, but in rivers with wide beds, otters can find suitable shelter on small islands covered by dense shrubs. Fishing, sheep herding and cattle-grazing do not seem to influence the presenceof otters. However, hunting, although practised by few hunters (some thousands), is an important limiting factor. Nevertheless, the Albanian Government, showing sensitivity to our requests, intends to protect the otter from 1986 onwards, allowing only the control of animals damaging fisheries. Albania holds a fair population of otters and this agreessubstantially with the results obtained in previous surveys in the southern range of the species, except for southern Italy (Macdonald & Mason, 19836). For the conservation of this important population, practical measures
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are needed as soon as possible to avoid the isolation of southern and northern populations. For Greece, Macdonald & Mason (1985) suggestedthe establishment of ‘river parks’ in riparian habitats, these being owned by the State. This solution would be highly suitable for Albania, where private property is absent. ACKNOWLEDGEMENTS We are very grateful to the Albanian Government for the opportunity to carry out this work, to the Faculty of Natural Science of the University of Tirane for the assistanceoffered, to Prof. F. Lamani for the help in fieldwork and to Dr S. M. Macdonald and Dr C. F. Mason for the revision of the manuscript. REFERENCES Chapman, F. J. & Chapman,L. L. (1982).Otter survey of Ireland 1980-81. London, Vincent Wildlife Trust. Elliot, K. M. (1983). The otter (Lutra lutra L.) in Spain. Mammal Rev., 13, 25-34.
Green, J. & Green, R. (1980). Otter survey of Scotland 1977-79. London, Vincent Wildlife Trust. Green, J. & Green, R. (1981).The otter (Lutra lutra L.) in western France. Mammal Rev., 11, 181-7. Liles, G. & Jenkins, L. (1984). A field survey for otters (Lutra lutra) in Yugoslavia. J. Zool. Lond., 202, 282-4. Macdonald, S. M. & Mason, C. F. (1982a). The otter (Lutra lutra) in Central Portugal. Biol. Conserv., 22, 207-15. Macdonald, S. M. dz Mason, C. F. (1982b). Otters in Greece. Oryx, 16, 240-4.
Macdonald, S. M. & Mason, C. F. (1983a). The otter (Lutra lutra) in Tunisia. Mammal Rev., 13, 35-7. Macdonald, S. M. & Mason, C. F. (1983b). The otter (Lutra lutra) in Southern Italy. Biol. Conserv., 25, 95-101. Macdonald, S. M. & Mason, C. F. (1983~). Some factors influencing the distribution of otters (Lutra lutra). Mammal Rev., 13, l-10. Macdonald, S. M. & Mason, C. F. (1985). Otters, their habitat and conservation in Northern Greece. Biol. Conseru., 31, 191-210. Reuther, C. & Festetics, A. (eds) (1980). Der Fischotter in Europa. Verbreitung, Bedrohung, Erhaltung. Oderhaus-Gottingen, Selbstverlag.