Large Mammals (Macromammalia) of Bulgaria
Geko Spiridonov and Nikolai Spassov
Summary
The earliest scientific studies on the living and fossil large mammals inhabiting Bulgaria date from the end of the 1800s. Research has become much more intensive over the last two decades, developing along three main lines - game biology, species morphology and taxonomy, and species ecology and status. There is still considerable ambiguity regarding the ecology and intraspecific taxonomy of a number of species. For this reason, research to clarify the status of the large mammals and to determine conservation measures is of paramount importance.
Bulgaria's specific zoogeographic location and the nearly intact state of its natural areas are the main factors behind the occurrence in the country of a rich and characteristic mammalian fauna. The number of large mammal species is 23. They are distributed in the different orders as follows:
Carnivora 14 species Pinnipedia 1 species Cetacea 3 species Artiodactyla 5 species These figures do not include exotic species, or those that have been introduced but have not successfully adapted.
The largest group is the carnivores. They are the most greatly influenced by anthropologic factors (two species have gone extinct in Bulgaria in the present century). Two species and one subspecies - the wolf (Canis lupus), otter (Lutra lutra), and European marbled polecat (Vormela peregusna peregusna) - are listed in the IUCN Red List of Threatened Animals. The long-term preservation of the marbled polecat in Bulgaria would be one of the required actions for its conservation on the European scale.
Also heavily impacted are the marine mammals. One of the dolphins - the bottle-nosed porpoise (Phocaena phocaena) appears on the IUCN Red List of Threatened Animals. Two of the three dolphin species (represented by endemic subspecies) are endangered. The monk seal (Monachus monachus), a species included in the World Red Data Book, is virtually extinct in Bulgaria. Due to the work of the state game husbandries, populations of the artiodactyls have been maintained at stable levels up until now. The only exception is the endemic Balkan chamois (Rupicapra rupicapra balcanica).
Active anthropologic influence on the large animals began a long ago - in the Neolithic, which developed and flourished in the Balkans one to two thousand earlier than in other parts of Europe. The diversity of natural conditions and the lay of the land in Bulgaria have contributed to the preservation of rare species and subspecies that have long been extinct in other parts of Europe.
The direct deterioration of natural habitats is the main factor behind the recent disappearance of species. Right after this in importance is the direct extermination of species. Last, though not least as a threatening factor, is the disturbance of both species and their habitats.
To ensure long-term preservation of the large mammal fauna, further studies of the status and in some cases the ecology of the species is urgently needed. Among the other important prerequisites for the preservation of the large mammalian fauna are: improvements in degraded habitats; effective protection of the natural habitats that still exist; reintroduction of some species, and captive breeding of others; increased international cooperation in the area of nature conservation; and the development and adoption of additional legislative measures.
History of the Studeis of Macromammalia in Bulgaria.
Macromammalia, or the large mammals, do not represent a group in the taxonomic sense of the term. The term is largely accepted and regularly used to unify a group of species belonging to different taxa that are characterized by their large size and that occupy a specific place within their ecosystems. The term Macromammalia also covers a range of species that, due to the characteristics noted above, are of high ethnological significance. Because of their relationships to the life styles, economic activities, and folklore of people, their aesthetic appeal, and their scientific importance, they are of special and definite interest to mankind.
Specialized data on the large mammals was first compiled after the national liberation of Bulgaria at the end of the last century (e.g., the studies of Khristovich and Irecek). The first systematic information in this field was published in The Mammal Fauna of Bulgaria by Kovatchev (1925). Susbsequently, trends in research in the field of mammalogy placed considerable emphasis on surveys of the micromammalia rather than the macromammalia. This trend continued up until the end of the 1980s.
By contrast, the study of paleomammalogy in Bulgaria (as elsewhere) began with surveys of the macromammalia. The first studies of fossil remains date from the end of the last century (Fush, 1879) and the beginning of our century (Bontchev, 1900). The development of our knowledge of the Quaternary large mammals is associated with the name of Rafail Popov, whose work was undertaken mainly between 1910 and 1940. The most important studies of the Neogene large mammalian fauna were carried out mainly by P. Bakalov, as summarized in the volume Tertiary Mammals (Bakalov and Nikolov, 1962) in the series The Bulgarian Fossils. Between 1960 and 1970, paleontological surveys were carried out by I. Nikolov. The names of D. Halvadjiev, G. Markov (senior), and D. Kovatchev should also be noted. Since the early 1980s, these studies have been conducted mainly through the National Museum of Natural History in Sofia (see N. Spassov's works). A new stage in terms of a systematic approach to the study of the Quaternary fauna was marked by the Paleolithic excavations of the Bulgarian-Polish team in the Batcho Kiro Cave (Kozlovski, 1982). In terms of the Neogene fauna, a similar stage has now been reached in the work of the Bulgarian-French excavations near the village of Dorkovo (Thomas et al., 1986).
The sub-fossil Holocene fauna, although discussed in a number of works - the more substantial of which are those of Ivanov and Vassilev (1975) and Vassilev (1985) - has been looked upon in a traditional manner; that is, predominantly from the point of view of archeology and the "Ancient Man" mode of life. Only during the last ten years have more systematic investigations of the formation and evolution of the Holocene large mammals begun (N. Spassov, 1990 a, 1992; I. Spassov, in press).
The monographs of Atanassov (1953, 1958) should also be pointed out as important pioneering works. Basic data on species distribution were included in some zoogeographic and general faunistic works published between the 1930s and the end of the 1960s (e.g., Beotiher, 1933; Atanassov and Peshev, 1962; Zimina, 1962; Peshev and Boev, 1962; Marches, 1970). Publications focusing on particular species are scarce until the late 1970s. They are concerned mainly with data about the discovery of the species and its distribution in the country. Such are the works of Ruskov (1961), Buresh and Boev (1951), and Atanassov (1966, 1968). In these works, there is much discussion of the "damage" caused by predatory species considered "harmful" at that time.
Research on the contemporary large mammal fauna of Bulgaria became more intensive in the 1970s and 1980s, with the establishment of 3 main research trends:
1. Game biology (e.g., Petrov et al., 1968; Dragoev, 1978; Grigorov, 1979, 1982; Grigorov and Djam-bazova, 1985; Genov, 1985, 1987a, 1987 b; Genov and Kotsakov 1986.
2. Morphology and taxonomy (among the most important papers are: Ruskov and Markov, 1974; Gerasimov, 1983, 1985; Markov et al., 1985; Markov et al., 1989; Spassov, 1989, 1990b; Ganchev, 1990; Petrov et al., 1990; Petrov et al., 1992; Genov et al. 1991; Massei et al., in press; Spassov and Spiridonov, in press). In this field the karyosystematic-biochemical approach has also been introduced (see Peshev et al., 1985; Markov and Dobrianov, 1985: Markov et al., 1984).
3. Research on the status and ecology of species. This work has also involved ethological studies. In some cases, attention has focused on species important for hunting and in forestry. However, a trend toward comprehensive studies of threatened species has also been established. In addition to the chapters on large mammals in the Bulgarian Red Data Book (1985), prepared mainly by Spassov and Spiridonov, a number of other important papers should also be pointed out: Tjufekchiev, 1978; Ganchev, 1979, 1982a, 1982b, 1986; Raichev, 1988; Genov and Ganchev, 1987; Genov, 1989; Genov and Vassilev, 1989; Ivanov, 1988; Spiridonov and Spassov, 1989, 1990; Spassov, 1993. (Note: the publications of Ganchev and Raitchev are actually by the same author, R. Gantchev Raitchev). Works on parasitology and paleozoology are not included here.
Main Gaps in Knowledge
Game species and species important in terms of forestry and agriculture have been the subjects of many studies. Special attention has recently been given to issues involving the morphology of the carnivores, using new qualitative and statistical methods. These studies are relevant to questions related to the intraspecific systematics and ecological adaptations of the species. This trend emerged mainly during the 1980s. Many of those studies have not yet been published. Studies of this sort deserve special attention, and are important on more than a theoretical level. The clarification of a population's taxonomic status - that is, whether a given population is unique or not in terms of the species gene pool - is of a primary importance in evaluating its conservation status. This can be seen, for example, in the discussions below of the marbled polecat, Balkan chamois, and bear.
The most poorly studied aspect of the large mamas is their ecology. This is particularly a concern with species that are difficult to observe, such as the carnivores. Such research is of paramount necessity. It is in fact the carnivores that are the most endangered group of large mammals, and because of the lack of information about them, the status of many species is not clear. Detailed studies on the biology of these species and their habitats will be extremely beneficial in determining and eliminating the factors that threaten their survival.
Analysis shows that, despite a rapid increase in the number of studies on the conservation status of the fauna in the last 10-15 years, data on habitat quality, conservation status, and protection measures for most large mammal species (especially the carnivores) remains scarce (see Table 1).
Current Assessment
The specific zoogeographic location, variety of natural conditions, and preservation of almost intact natural areas (see the next item) in Bulgaria are the main factors accounting for the existence here of a relatively rich and, in some aspects, unique large mammal fauna as compared with that of other European regions.
The following analysis of the fauna is presented in systematic order, with the threatened species discussed in much greater detail at the end of each family section. Of the various orders of mammals found in Bulgaria, the following are included in the group of large mammals (Macrommalia): Carnivora, Pinnipedia, and Artiodactyla. The category of threat is determined according to the criteria given in the IUCN Red Data List.
1. Carnivores (Carnivora)
1.1. Dogs (Canidae)
1.1.1. Golden jackal (Canis Aureus)
In Europe, this seems to be a single species, despite the presence of certain distinct populations. It is the same species that inhabits the Caucasus and Asia Minor (Spassov, 1989; Demeter and Spassov, 1993). The jackal reached Europe after initially occupying the Balkans, where it seems to have arrived during the Holocene by swimming across the Bosphorus (Spassov, 1989). Its population and range began to expand rapidly in the early 1970s and reached a maximum in the middle 1980s. This trend has not yet diminished even today. This is probably the greatest expansion of the jackal in Europe since concrete information about its distribution became available (that is, since the beginning of the century) (Spassov, 1993).
Most recently, migrants from the east have reached northern Italy. It is interesting to note that the general expansion of the species to southeastern Europe has not influenced the status of the jackal in Greece, where an isolated population occurs (Ioannidis and Giannatos, 1991; Adamakopulos et al., 1991).
Investigations in Bulgaria, which is a center of its distribution in Europe, show the speed, direction, and density of its distribution. At the beginning of the century, the jackal was distributed throughout the southeast part of the country. The destruction of its habitat pushed it toward the extreme southeastern portion of its range. In the 1950s its main stronghold was along the Black Sea Coast south of Bourgas and Strandzha Mountain. It was designated a rare species in 1962, after which time its numbers became more stable. By the mid-1980s, it had reestablished itself over almost the whole country. Since then, the population has been relatively stable. Its numbers have been controlled since the late 1970s, and in 1984 its protected status was abolished.
The population boom is due to a number of factors (Spassov, 1989). According to some calculations, its number at the end of the 1980s comprised about 7,500 animals (Rosler, 1989). This figure seems exaggerated. We estimate its population (in early spring) to be at under 5,000 animals.
1.1.2. Red fox (Vulpes vulpes)
Widespread. The population in 1983 was estimated at more than 53,000 animals. Populations are most dense in typical field habitats, primarily in northern Bulgaria (Grigorov, 1987).
1.1.3. Racoon dog (Nyctereutes procyonoides)
This species was introduced into Europe earlier this century, and consequently is of little interest from the standpoint of the protection of natural ecosystems and species. The species migrated on its own into Bulgaria from the northeast, expanding out from an artificially introduced population in Eastern Europe. It was first recorded in the northeast part of Bulgaria, near Shabla, in 1968 (Dragoev, 1978). It inhabits primarily marshes and lakeshores. In 1971 the species was found in the Pleven area, as well as the Silistra area (Srebarna Lake). By the mid-1970s it seems to have expanded beyond the Stara Planina range and since then has been observed in the lower parts of the Teteven range (St. Chovkanski, pers. comm.). By the late 1970s it was recorded at different sites in the Sofia area. At present the species seems to have reached southern Bulgaria. It has been observed at Atanassov Lake (Bourgas). Everywhere the species is rare.
1.1.4. Wolf (Canis lupus)
This species reached its critical minimum (about 100 individuals) in the late 1960s and early 1970s. In the 1970s its numbers increased slightly, but remained low. By the beginning of the 1980s, the population comprised about 200 individuals. In 1985 the species was listed in Bulgarian Red Data Book (Spiridonov and Spassov, 1985a). In the 1970s and 1980s, as the wolf population remained low, the number of feral dogs, and hence of dog-wolf hybrids increased, as for example in the western Stara Planina (Djuninski, pers. comm.). This phenomenon has been observed in similar situations in other parts of Europe, and constitutes an additional danger for the wild species.
After 1980, the population began to increase rapidly. It is interesting to note that the drastically depleted population of wolves in Romania has also begun to increase (see Rosler in Zeitschrift fuer Siebenburgisshe Landeskande, 15 (1) 1992). The mass movement of wolves to from Romania across the Danube to Bulgari has not been recorded since the 1950s. The highest density in the Balkan Peninsula - at about 300-500 individuals in 1991, it is a bit lower than Bulgaria's - is found in the border region of Greece (see Hatzirvassanis in Biol. Gallo-Hellen.18 (1):13-20). The increase in the number is due most probably to several factors, including an increase in game animal populations in Bulgaria, extensive cattle breeding (as in the eastern Rhodopes), and small human populations in areas with suitable habitats (i.e., regions with good breeding conditions, deserted areas, etc).
According to an inquiry made among the State Forestry Departments in 1989-90 (Spiridonov, and Mileva, unpub.), the wolf population has increased almost four times and its species range between - 2.5 and 3 times from 1978 to 1988. Thus, its population now covers more than 2/3 of the forest area of the country. The inquiry also showed that 1/2 of the territory of the country is populated by feral dogs, and only half of this area is occupied by wolves.
The wolf is now reclaiming areas, such as Sredna Gora and Central Stara Planina Mountains, from which it disappeared 20-30 years ago. The largest population remains in southwest Bulgaria and in the eastern Rhodopes Mountain. The especially high number of wolves shot since 1987 indicate an annual increase of 200 wolves (Velitchkov, pers. comm.) This data allows us to estimate the number of wolves at between 600-700 in the spring, before the young are born.
Classified as an endangered species in the Prognosis of the Condition of the Endangered Mammal Species in Bulgaria (Spiridonov, 1989), the wolf can now be transferred to the "vulnerable" category - a lower level of endangerment - where it is also classified on the IUCN World Red List (1992).
1.2. Bears (Ursidae)
1.2.1. Brown Bear (Ursus arctos)
This is a rare species in Bulgaria, potentially threatened with extinction due to its limited number and territory and the pressures of anthropogenic impacts. Since the liberation of Bulgaria - i.e., in less than 100 years - the bear has disappeared from 2/3 of its previous range. In the 1930s it reached the low point in its numbers - about 300 individuals. After the hunting of bears was banned in 1941 the population gradually increased. Today the population has grown 200-250% above its low point, although with few exceptions it has not recolonized its previously inhabited territories.
Presently the species survives as four local populations in the mountains above 700-800 m in elevation: the central Stara Planina, the Rila, the Pirin, and the western Rhodopes. The latter three populations are more or less connected through the mountains south of Sofia. The Stara Planina population, however, is isolated (Spiridonov and Spassov, 1990). During the 1980s, some researchers estimated the total number of bears at over 800; a more realistic figure would be 750 bears at the end of the 1980s (Spiridonov and Spassov, 1990). The previously mentioned inquiry among the State Forestry Departments (Spiridonov and Mileva, unpub.) found 210 individuals in the Rila-Rhodope population in 1989-90.
The recent creation of two bear-hunting husbandries - in the Rhodopes (Kormisosh) and in the Central Stara Planina Mountains - and the introduction there of captive-bred bears from the Carpathians and elsewhere has had negative impacts on the bear population. It has resulted in a sharpening of the conflicts between bears and people and has damaged the genetic purity of the population. At present, greater scientific attention is being focused on the unclear taxonomic status of the Balkan bear, and on the species' genetic characteristics and diversity, based on morphological and zoogeographic considerations. (Spassov, 1990).
The Balkan bear differs in its morphology and behavior from the more northern Russian-Carpathian population. The present population of the Balkan brown bear probably resulted from crossbreeding between the Pleistocene-era local Mediterranean population (closest to which is the Syrian type) and an U. a. arctos population migrating from the north in the late Pleistocene and early Holocene. Some Russian scientists (Tihonov in The Ecology of Bears, 1987) suggest that crossbreeding occurred between the Syrian and Caucasus subspecies. Genetic investigations (Taberlet and Bouvet in C.R. Acad. Sci., Vol. 134, Ser. III, pp. 15-21, 1992; Taberlet, pers. comm.) show a significant difference between the Iberian bear (which is close mor-phologically to the Balkan bear) and the bear of Central and Northern Europe.
The resumption of legal bear hunting in Bulgaria in 1984 (after 43 years of protection) and the increase in poaching in the last 3-4 years (as a result of destabilization in the forest and hunting administrative structure) are potential threats to this species. These trends made it necessary to proclaim the bear an endangered species in January 1993. There are also some 30-40 dancing bears in Bulgaria. These domesticated bears should be registered and immediate steps taken to prevent their increase and reproduction.
1.3. Weasels (Mustelidae)
1.3.1. Weasel (Mustela nivalis)
The weasel is widely distributed in Bulgaria. Because it is a useful natural predator of rodents, it has been protected by law since 1962. The Bulgarian population belongs to the group of large Mediterranean and Asia Minor weasels. The Balkan weasel may be a separate subspecies, but its taxonomic status needs further clarification (Peshev et al., 1985; Douma-Petridou and Ondrias, 1986).
Note: it has been reported that remains of the stoat (i.e., the ermine Mustela erminea) were found in pellets of the eagle owl in northeastern Bulgaria. Despite additional reports of this species in Romanian Dobrudzha and some dubious data from northeastern Bulgaria (N. Spassov, unpub.), there is no positive proof that this species occurs here (see Spassov, 1980).
1.3.2. European mink (Mustela lutreola)
The species was last described in the early 1950s, when it was reported along the eastern Danube. It is listed in the Bulgarian Red Data Book (Spassov, 1985) as an extinct species.
Note: The American Mink (Mustela vison) has not reached Bulgaria and has not been intentionally introduced in the country. In the 1960s individual animals were observed in southern Bulgaria after they had escaped from mink farms. No subsequent observations exist. The species has definitely not acclimatized.
1.3.3. European polecat (Mustela putorius)
A widely distributed species. In the 1970s and early 1980s the market in game furs in Bulgaria was annually supplied with about 6000 furs from this species. A slight downward trend in the population exists. Changes in the distribution of the species in Europe (including Bulgaria) are currently being investigated (De Marinis, under preparation).
1.3.4. Stone marten (Martes foina)
Widely distributed species. It occurs in all forest types as well as open biotopes with bushes and rocks. It occurs in coniferous forests up to 1,800 m, but is more typically found in broad-leaved forests up to 1,000 m coniferous forests up to 1,500 m (Grigorov, 1986). A strong tendency to associate with human settlements can be observed; the species has been seen several times within Sofia, even in the center of the city (N. Spassov, pers. obs. The species seems to prefer drier terrains, broad-leaved forests, and open rocky habitats. The stone marten (moreso than the pine marten) can readily exist in populated areas where large forests have been cut in recent decades. It easily inhabits even houses and other buildings (particularly deserted buildings). As a result, this species exists in high numbers, and inhabits almost all types of suitable habitat. Grigorov (1986) estimated its population at around 35,000.
1.3.5. Badger (Meles meles)
Widely distributed, the badger inhabits hilly-plain regions in the oak forest zone. In 1986 its population numbered about 30,000 (Grigorov, 1986).
Threatened Species of Carnivora
1.3.6. Steppe polecat (Mustela eversmanni)
Definitive identification of this species' conservation status is difficult, since scientific data is not sufficient to specify its degree of endangerment. It is obvious that the species is in danger. It inhabits limited territories, and in these is rarely met. It is known to occur in northeastern Bulgaria. It range seems also to extend west within the Danube valley (Spassov and Spiridonov, 1985). The borders of its area of distribution are not quite clear. It is quite probable that the mass poisoning of rodents that occurred in open areas in the late 1980s proved fatal for the Steppe Polecat.
Observations were made in the early 1980s, but un-fortunately no special studies have since been undertaken. The species was first formally reported in the country in 1951 (Buresh and Boev, 1951), although a representative specimen has existed in the collections of the National Natural Scientific Museum show since 1931. These and other facts contradict the hypothesis that the species moved east in the 1940s and 1950s in response to deforestation. It is probably a Lower Pleistocene relict (for details, see Spassov, 1982). This hypothesis finds support in the re-cent discovery of a skull of this species from the Neolithic in the Durankulak excavations (determined by N. Spassov).
1.3.7. Marbled polecat (Vormela peregusna)
Information on the European Marble polecat (Vormela peregusna peregusna) is available only for Bulgaria, which is the center of the subspecies' range. In response to a proposal by Bulgarian experts in 1985 (Spassov and Spiridonov, 1985), it was recently placed on the IUCN Red Data List of Threatened Animals. In Bulgaria, the species is probably relatively abundant, as it distributed in a mosaic-like pattern over a considerable territory. However, it is subject to strong human impacts. We consider the species to be vulnerable.
The Marbled Polecat occurs predominantly in the Danubin plain, the Thracian plain, in the Sofia area, and in the lower karst regions of the country. It inhabits open terrains. Consequently, its main territories are very vulnerable and have already been partially destroyed by the conversion of the steppe regions to cultivated land. During the last 200 years the species has disappeared from Pannonia and other areas of Eastern Europe.
The biology of this carnivore is poorly understood. Like the Steppe Polecat, its distribution is related to that of the large colonies of rodents (hamsters, dormice, etc). The relationship between the two polecat species seems to be strongly competitive (Spassov and Spiridonov, in press). Additional research is needed. A comprehensive program for the study and conservation of the Marbled Polecat within the different steppe communities of Bulgaria should be undertaken. This would be an important step in ensuring protection of the subspecies generally.
1.3.8. Pine marten (Martes martes)
At present this species is regarded as vulnerable. It inhabits forest habitats over 1000 m a.s.l., its typical habitat being areas over 1500 m (i.e., higher than the habitat of the Stone Marten) (Grigorov, 1986). In 1986, the population numbered about 3000. The species occurs in the low mountainous regions, such as Strandzha Mountain and the Stara Planina Mountains, as well as in the Loudogorie region (Spiridonov, unpub.).
Between the 1940s and 1960s the Pine Marten was in danger of extinction and ceased to exist in the valleys and the foothills of the mountains. Over the next 10-15 years, after measures were taken to control the hunting of fur-bearing animals, the number of both the Stone and Pine Marten increased. While the number and distribution of the Stone Marten continued to expand in the 1970s, a new period of crisis began for the Pine Marten, most probably in connection with the massive cutting of old forests. In young forests the Stone Marten replaces the Pine Marten (Spassov and Spiridonov, 1985; Spiridonov, 1989). At this time the number of pine marten furs in the Central Game Fur Store decreased from 5% to some 1% of those of the stone marten.
The main threats to the species are the changes in, and loss in area of, its typical habitats. This is aggravated by other anthropogenic pressures and competition with the Stone Marten. Direct exploitation is a third important threat, although the species is protected in the higher parts of the mountains and within the borders of vast mountainous national parks and reserves.
Delibes (1983) and Fennika (1974) offer the hypothesis that the competitive relationship between the Stone and Pine Marten has altered the partitioning of habitats between the species. According to this hypothesis, the Pine Marten is in direct competition with the Stone Marten and pushes it out of its inhabited forests, forcing it to occupy more open rocky and bushy terrains as well as settled areas. On the basis of paleontological, paleozoographic, and ecological data, we (Spassov) suggest another model of competitive relations: that the origins of the Stone Marten as a species lie in the Pleistocene and was connected with the expansion of the forest-steppe and open, dry, rocky, bushy regions in Central Asia. The Pine Marten survived as a more specialized predator in the mountainous relict forests in the montane regions of Asia Minor, the Caucasus and Urals, and perhaps southeastern Europe. Changes in the forests during the Holocene were beneficial for the Stone Marten. The last glaciation allowed the species to migrate to the western parts of the continent. After that it was aided by the constant human activity in the region, especially the gradual deforestation. In one and the same biotope, the species occupied different ecological niches. Urbanization, land abandonment, and the recent massive deforestation have created habitats that imitate those typical for the Stone Marten, and at the same time are unsuitable for the Pine Marten.
1.3.9. Otter (Lutra lutra)
The otter is a vulnerable species. The most critical period for the otter in Bulgaria occurred prior to the mid-1960s, when it was declared a protected species. Its food base, which had been lost due to industrial pollution of rivers, was reestablished with the construction of a large number of fish breeding ponds and dams. As a result, the number of otter has increased. The otter's natural living conditions, however, have continued to deteriorate throughout the species' entire range. Consequently, the species was entered in the Bulgarian Red Data Book. It should be mentioned, however, that the status of the otter in Bulgaria is markedly better than in other European countries. Three-fourths of its natural habitat occurs in areas under 1000 m in elevation (Spiridonov and Mileva, unpub.). The high density of the otter population in southeast Bulgaria and the total number of the species - some 1000-1400 individuals (Spiridonov and Spassov, 1989) - are proof that the species, though vulnerable, is not highly endangered within Bulgaria.
1.4. Cats (Felidae)
Both representatives of the Felidae family in Bulgaria are classified as endangered. One is considered extinct (see below).
1.4.1. Wild Cat (Felis silvestris)
This species is considered rare in Europe, although it would probably be better characterized as vulnerable in view of the continual decline in its population. The decline is due to continuous persecution and crossbreeding with feral domestic cats. Some years ago, Suminski identified this latter factor as the reason for the lack of purebred wild cats in Central and Western Europe. This conclusion borders on the extreme, but also extreme is the conclusion of Ragni and Randi (1986), who practically deny the role of hybridization. It must be pointed out that their conclusions are based on specimens from Italy, where hybridization occurred as far back as Roman times. As a result, the distinction between actual "wild" cats and domestic cats "gone wild" is vague (Spassov, unpub.).
Not counting the Caucasus population of Felis silvestris, the Balkan population of this species outnumbers all others in density and is of utmost importance for the preservation of the species in Europe. The biotopes are extremely suitable in the Balkan peninsula and especially in Bulgaria. According to Petrov (1991), the average annual population of the species in Bulgaria between 1969 and 1989 was about 5340 individuals. The population was most dense in the lower mountains and hilly forest regions - up to 0.84 individuals per 1,000 ha (petrov, 1991). He estimates the numbers of wild cats as 3,700 individuals in the spring. According to our estimations the numbers are firmly over 4,000. In his calculations, Petrov has overlooked natural mortality as well as incidental death caused by night traffic on the highways (which according to Stahl and Aritos is rather high in other European countries). If these facotrs are taken into account, a lower population number results.
Although the status of the species is satisfactory - irrespective of the immense persecution it experiences (see Petrov, 1991) - we consider the wild cat a potentially endangered species. Until their status is clarified, we have placed it in the category "status unknown." The main threat is hybridization with feral cats. Research carried out on 350 wild cat furs in 1986 proved that at least 5% of the furs entering Bulgaria's central fur storage unit were from hybrids. A much higher percentage showed signs of more distant crossbred. Furthermore, the Bulgarian population is one of the purest. The status of the wild cat in the country, especially the main centers of hybridization, is under investigation at the moment.
1.4.2. Lynx (Lynx lynx)
Here, and in the Bulgarian Red Data Book, we list the lynx as an extinct species (Spiridonov and Spassov, 1985). The last lynx in the Rila Mountains (and in Bulgaria) was recorded in 1941 (Spiridonov and Spassov, 1985) and was killed in Parangalitsa. The last occurrence in the central Stara Planina Mountains was recorded near Karlovo in 1940. We have compiled more than 20 published accounts of lynxes observed or killed from the 1950s to the present. According to these accounts, lynxes have been present in the regions of Ihtiman and Sustinska in the Sredna Gora mountains, in the central Stara Planina Mountains, the Rila and Strandzha Mountains, and even in northeastern Bulgaria. Many "observations" were based on rumors in the press of the lynx's return. Other rumors are probably based on the vivid imaginations of wild animal lovers and their desire to encounter this "enigmatic" creature. There is evidence, however, of individuals surviving into the 1950s (for example, at Strandzha Mountain in 1952) and, until the late 1960s, of individuals drifting into Bulgaria from Macedonia (where its population has increased greatly). The same sort of evidence (i.e., unconfirmed observations and reports of tracks) indicates the possible existence (through migration?) of the lynx in northern Greece (see T. Komninos and M. Panagiotopoulou in Biol. Gallo-Hellenica 18:75-80). At present, however, it would be presumptuous to assume that the lynx has spontaneously reestablished itself in Bulgaria.
With the support of the European Council, preliminary research has begun on a joint project of the Ministry of Environment and the Wilderness Fund (an NGO) to re-introduce the species in Bulgaria. The species has been successfully reintroduced in five European countries, and has recently migrated into another - Italy - on its own. In seven other countries its numbers have recovered after the species was on the verge of extinction. In Bulgaria conditions to support a vital wild population are best in some of the montane forest regions, where the lynx is the most promising predator for the hoofed animals and for the improved functioning of the forest and mountain ecosystems.
2. Seals (Pinnipedia)
2.1. Black Sea monk seal (Monachus monachus).
An endangered species. Even though a very rare encounter of monk seals is theoretically possible along the Bulgarian Black Sea coast, in reality the species should be considered extinct. The statement that it inhabits the Bulgarian coastline around Capes Kaliakra and Maslen Nos (Izraels, 1992) is based on old data. Its population within the country is "skeletal" and its self-restoration is already impossible. It is difficult to know whether it would be possible to support a viable population of the monk seal. Lone individuals have made their way north from the Turkish coast, where some 40 are said to survive. Another ten may inhabit the Marble Sea (Gurpinar, pers. obs.). Bearing these number in mind, it is highly likely that the species will be extinct in the next few decades if its population is not genetically enhanced.
The largest habitat along the northern coast of Bulgaria had been at Cape Kaliakra, but the species has neither bred nor been observed there since 1979 (Michev, 1985). There is one observation dating back to 1981 (St. Andreev, pers. comm.) and an unconfirmed report from 1987 (St. Vamporov, pers. comm.). The most reliable recent observation in the northern Bulgarian Black Sea coast region occurred in the vicinity of the Shabla lighthouse in 1982 (Spassov, unpub.).
Data from the same survey supported several occurrences along the southern Bulgarian Black Sea coast. A monk seal was observed in the vicinity of Cape Maslen in the early 1980s (Spiridonov, unpub.). A few years later the species was photographed near the Michurin coast by a German vacationer (Boev, pers. comm.). In 1987 a seal pair was observed on a number of occasions north of Tsarevo. A year later the sea cast up the dead body of a young seal in the same region (St. Vamporov and Kumanski, pers. comm.).
During the 1970s local fishermen observed at least one seal couple in the caves along a stretch of coast 1-3 km north of the village of Rezovo. In 1987 a diver spotted a large adult specimen in the cave nearest to the village (Biolchev, pers. comm.). The latest report dates from 1991, when an individual seal was spotted on the beach near Tsarevo by Ivan Kubat of the Prague Zoo (Kubat, pers. comm.). It is most likely that the southern Bulgarian Black Sea coast is inhabited by 2 or 3 adult individuals (and a maximum of 1-2 mature females), while single (young?) individuals sporadically reach the northern coast.
3. Whales (Cetacea)
3.1. Dolphins (Delphinidae)
Three species of dolphin occur in the Black Sea: the common dolphin (Dolphinus delphis), the harbor porpoise (Phocaena phocaena) and the bottle-nosed porpoise (Tursiops truncatus). The bottle-nosed porpoise and harbor porpoise are endangered species. These species are represented in the Black Sea by endemic subspecies (T. trancatus ponticus and Ph. phocaena relicta). They are endangered despite a 1966 agreement involving Bulgaria, Rumania, and the former Soviet Union that terminated the catching of dolphins.
The status of dolphins in the Black Sea has not been studied thoroughly and further investigations are urgent needed. It has been estimated that the ratio of the common dolphin to harbour porpoise to bottle-nosed porpoise is 200:10:1 (Peshev, 1985). The reproductive potential of the bottle-nosed porpoise is very low, and its average density in the Black Sea is 1 per 1000 km2. Its population along the Bulgarian shoreline barely exceeds some few dozen. It is likely that the species is drifting further out into the Black Sea due to pollution of the coastal waters (see the Red Data Book of Russian Republic of the USSR, published in 1983). According the same Red Data Book, the species numbered some 36,000 in 1977. The harbour porpoise is vulnerable all along the European coasts, but the Black Sea subspecies is especially endangered. Over the last few years the population has experienced high mortality rates as a result of unknown, and practically unstudied, reasons.
4. Artiodactyls (Artiodactyla)
(Figures involving game species are provided by V. Velichkov of the Ministry of Environment).
4.1. Boars (Suidae)
4.1.1. Wild Boar (Sus scrofa)
After a significant decline in the population of the wild boar in the 1950s, measures were taken to encourage its reproduction. Now it is widely distributed throughout Bulgaria. In some places, the species is so abundant that it causes damage to agricultural fields, forests, and game breeding areas. Numbers: 1147 in 1951; 48,880 in 1992 (spring count).
4.2. Deer (Cervidae)
4.2.1. Fallow deer (Dama dama)
The chronological record of bone remnants from this species in the Balkans is almost continuous, and may provide a clear answer in the controversial issue of its existence as a native Holocene population in Europe. The population has survived for a long time in southeastern Europe. Its presence in these regions can be followed through bone remnants from the former Yugoslav Republic (at the end of the Pleistocene), to Bulgaria and Romania (through the Neolithic and the Eneolithic times), and in Bulgaria through the Thracian and Roman eras up to the late Middle Ages (N. Spassov et al., in press). The present European population seems to have been reintroduced on the continent since Roman times. At the end of the 1940s it was introduced and released in Bulgaria (Dragoev, 1978). It has practically reestablished itself in portions of the Danubian plain, the northern slopes of the Stara Planina Mountains, the Sredna Gora, and the Strandzha-Sakar Mountain region (according to data of the former Ministry of Forests in the early 1980s).
4.2.2. Red deer (Cervus elaphus)
This species was close to extinction in Bulgaria during the 1930s and 1940s. It is now widely distributed. Favorable natural conditions, especially in northern Bulgaria, have a positive influence on the species, which is high valued for hunting trophies. Archeozoological remains indicate that populations during the neolithic and eneolithic epochs were even larger than at present (N. Spassov and Iliev, unpub.). The question of whether the Balkan population is taxonomically distinct, raised by Katsarov during the 1930s, remains unresolved. Numbers: 600-700 in 1932-33; 15,890 in 1982; 28,370 in 1992 (spring count).
4.2.3. Roe deer (Capreolus capreolus)
In the recent past this species occurred mainly in large expanses of forest and montane regions. Recently it has adapted to flat, slightly forested regions in northern Bulgaria as well. At present the roe deer is distributed almost everywhere in Bulgaria. Numbers: 9500 in 1952; 134,069 in 1982; 121,160 in 1992. The recent decrease is related to the weakening of forest and hunting administrative structures and the increased incidence of poaching that has resulted from the social changes of the last three years.
4.3. Cattle (Bovidae)
4.3.1. European bison (Bison bonasus)
The European bison was first bred at the Voden game farm and later at the Preslav farm. The bison live within fenced pastures, and are fed by people. They are not considered a truly native Bulgarian species.
Note: A few years ago a small group of yaks (Poephagus mutus) was released on an experimental basis. There are still several yaks in the central part of the Stara Planina Mountains. It cannot, however, be confirmed that this species has been totally naturalized. At the same time, we cannot support similar experiments with other game species, as they do not belong to Bulgaria's indigenous fauna.
4.3.2. Alpine ibex (Capra ibex)
This species was released in the wild for hunting purposes in 1978 in the northern Pirin Mountains and in the Rila Mountains in the region of the Beli Iskar dam. Although they have survived in these places for the last 15 years, we have no reason to believe that these small populations have been fully naturalized.
The question of whether the ibex (and which particular species) survived until the Holocene in Bulgaria is still controversial (see Spassov, 1982). The discovery of ritual astragaluses in an ancient Greek sanctuary (see Poplin in L'Antre corycien, II, Bull. de correspondence Hellenique, Supl. IX, Ecole Francaise d'Athenes) give some reason to believe that ibexes (either Capra ibex or Capra aegagrus) survived in the region until historic times. It is not known whether the remnants came from islands or from the continent, but most probably they are of a local (i.e. continental) species.
Note: A proposal has recently been made to introduce the bezoar ibex (Capra aegagrus) in the Rhodope Mountains. This is presently being discussed by experts in the Ministry of Environment.
The mouflon is barely able to survive in nature without artificial maintenance. There are some who believe that the Corsican mouflon is a primitive semi-domestic, rather than a wildlife, species (see Poplin). We do not accept the mouflon as a representative of the native Bulgarian fauna, although its population is increasing and in 1992 it has reached 3,870 individuals.
Threatened Species of Artiodactyls
4.3.4. Chamois (Rupicapra rupicapra balcanica)
The species is considered threatened due to its limited numbers and habitats and the existing and potential threats to its survival. The Balkan subspecies is included in the IUCN Red Data List of Threatened Animals. Its populations in Bulgaria are absolutely isolated. Only the Rila Mountain population, consisting of some 570-650 individuals, is relatively large. The western Rhodope Mountain population, with 380 individuals, is considered vulnerable, and the Stara Planina population of 170-200 animals is threatened with extinction (Spiridonov and Mileva, unpub.) The main threats to the species are: possible genetic deterioration as a result of inbreeding (Spiridonov, 1985), effects of previous hunting, and poaching.
Threats to the Survival of Large Mammals
The formation in Bulgaria of various and highly productive Holocene ecosystems, and within them a rich Holocene complex of large mammals, is due to a number of factors: the country's specific geographical location and favorable climatic conditions (in southeast Europe between the lower Danube, the Black Sea, and the nearby Mediterranean), its varied relief, the influence of the East European steppe community, and the presence of elements from the Asia Minor biota.
During the early Holocene, Bulgaria was inhabited by a great variety of cloven-hooved mammals, including 2 (possibly 3) equids, and 7 (possibly 8) species of artiodactyls (Spassov, 1990). The advent of the Atlantic Holocene and the deforestation of the high mountains may have created the conditions under which the ibexes disappeared (see above). This might also account for the extinction of the last European leopards, which were present through the Warm glaciation maximum, and probably survived as montane "island" populations in the Balkans. The latest remains (dated to 15,000-17,000 years ago) of this carnivorous species in Europe have been discovered in the Triugulnata Cave in the Rhodope Mountains in southeast Bulgaria (Spassov and Raichev, in press). Three discoveries of bone remnants indicate that the lion was present during the eneolithic epoch. Historical data shows that it survived until recently (Spassov and Bozhkov, 1981; Ninov, 1989). The neolithic revolution and the eneolithic cultures took hold in Bulgaria and the Balkans about 1000-2000 years before their development in other parts of Europe. These cultural changes no doubt influenced the animals and the natural environment in general, especially the plains, steppes, and forest-steppe regions. The last European "wild asses" (Equus hidruntinus) were found near Dobrudzha, haveing been extirpated exterminated 5,500 years ago (Nobis, 1986).
Highly developed cultures in the Thracian and Roman times exerted a strong negative influence on the native fauna and its species diversity. Roman inscriptions from the 2nd century a.d. in northeastern Bulgaria (the town of Montana and village of Staliiska machala) speak of impressive bear and bison hunting by one or more Roman cohorts and local huntsmen, and of transporting these animals to Roman arenas along the Danube. The last bison remains in Bulgaria date from the 9th-10th century a.d. The primitive European bison, or auroch (Bos primigenius), seems to have survived until the early 17th century. The fallow deer was definitely represented by an indigenous populations, the existence of which can be traced from the end of the Pleistocene to the Middle Ages (Spassov, 1990a).
Despite human impacts, the forests in the inaccessible mountainous regions of Bulgaria survived relatively intact over the centuries. Their varied topography made settlement difficult and has allowed species that were destroyed in most parts of Western Europe to persist here. This is especially true only for the carnivorous species. More critical is the status of the inhabitants of the plains, especially those species that live in open habitats and along the Black Sea coast (such as the monk seal).
The extent of the current threats to Bulgaria's species diversity is determined by a number of factors. Threats vary among the different taxa. Taxonomic differences reflect differences in biological "design" and thus in ecological and behavioral characteristics. The biological characteristics, ecological requirements, and adaptability of the various taxa determine the character of their relationships with people. This in turn determines the different threats that different species face.
The large mammalian carnivores are an especially important group in terms of the conservation of biological diversity. They constitute the largest and most diverse group. At the same time, this group includes the most critically endangered species in terms of their absolute numbers. This is due not only to the relatively high number of carnivorous species, but also to the various human factors affecting the group as a whole. These threats can be outlined as follows.
1. Predators are being exterminated by the deterioration of their habitats:
1.1. Direct destruction of refuge habitats (forests, bushes, coastline) and increases in the area of cultivated lands (affecting species of the open spaces).
1.2. Aggravation of the trophic base (affecting the lynx, etc.). It should be pointed out in this context that extinction may occur through the use of toxic substances to poison and exterminate harmful rodent species that serve as prey for the carnivores.
1.3. Disturbance (especially with regard to the bear).
1.4. Alteration of the natural balance between species as a result of human impacts on the environment (see the discussion of stone marten-pine marten competition above).
2. Direct human persecution and pursuit of predators
2.1. "Harmful" species (wolf, polecats, otter, etc.).
2.2. Hunted species of economic value (almost all species)
2.3. Hunted subjects with trophy value. (Recently trophy hunting has become highly fashionable and includes not only traditional species such as the bear, but also the wolf and wild cat).
All of these factors stimulate poaching of threatened species. It is not by chance that the two species that have disappeared during this century were from the carnivore family. If the monk seal (order Pinnipedia) is also included in the Carnivora, as most experts in systematics believe it should be, it becomes obvious that the same complex of threatening factor applies to it, namely:
1. Direct destruction of its habitats due to the development of the Black Sea coast, increased tourist pres-sure, and aggravation of the trophic base (i.e., the fish resources).
2. Direct extermination of the species by fishermen (a factor important not only in the past, but even now).
The dolphins (Cetacea) are in a critical state. Two of the three species, and especially the harbor porpoise, are threatened with extinction. As a threatening factor, the destruction of habitats has a certain specificity in this case: water pollution directly affects the organisms while also leading to the decline of the trophic base. Other factors, of course, are fishing and (in the past) direct extermination.
Hoofed animals, highly valued and threatened by overhunting in the past, now appear to be in a more favorable state than other large mammals. The establishment of well organized hunting husbandries after the 1950s, and the intensive efforts undertaken to maintain and develop them as game species, proved to be very positive factors. It does seem a paradox at first glance, but in fact centralized hunting (i.e., concern for the existence of the principal hunting species) proved to be the factor that prevented the complete extinction of the hoofed mammals.
It should be pointed out that since 1950 the status of most of the threatened species has declined, and one species - the monk seal - has almost disappeared. On the other hand, the status of some species has improved - bear, stone marten, chamois, and golden jackal (the last is no longer endangered). Control over their direct extermination has made this possible. The status of the otter and, more recently, the wolf may also have improved.
Analysis of the Bulgarian Red Data Book shows that direct destruction of natural habitats is the major factor threatening the country's large mammals. For ten of the species, it is a major factor, and for two others a factor of secondary importance. The second leading factor is direct exploitation of the species, and the third leading factor is disturbance.
Recommendations
It is obvious that the different ecological circumstances of the large mammal species and the various factors affecting them will determine the variety of measures needed for their long-term preservation. These measures can be classified into a few main groups. In Table 1, the need for different types of protective measures is rated on a scale of 1 to 3. This analysis indicates several critical priorities.
The most critical need is additional research on the extent of threat. In many cases, precise data on the status of the species, the threatening factors, and the extent of impact are lacking. This means that more detailed research on the biology of the species is also required.
Second, it is important that measures be taken to improve environmental conditions and to establish protected areas that encompass the main natural habitats of the species.
Third, other important protective measures need to be taken, including captive breeding, reintroduction, and (where appropriate) the introduction into new locations of endangered species; international cooperation and agreements on conditions for preservation; and additional legislative measures.
In our opinion, additional priorities for preservation should include:
1. Establishment of an single institution with the authority to carry out effective control of the protected areas. In this respect, the Ministry of Environment's proposal to establish a National Agency to safeguard the protected ares is timely.
2. Establishment of a governmental fund to reimburse landowners who have suffered losses on their farms from endangered species (at least within the natural territories of these species).
3. International cooperation to control pollution of the Black Sea, and to undertake additional protective measures. This is a major issue in efforts to preserve the sea mammals. The two endemic dolphin subspecies should be listed as endangered in the Bulgarian Red Data Book.
4. Reintroduction of species. This is another important tool for preserving biological diversity. In relation to this very sound general proposal (see above), specific actions should be taken to reintroduce the lynx. Re-introduction of the European mink and eventually the ibexes should also be considered (see the respective items above).
Table 1. Status of Large Mammal Species
Legend: E= Endangerd; U= Unclear Status; V= Vulnerable; Ex= Extinct or threatened with extinction; R= Rare
Degree of Threat Species Total Bear Wolf Steppe Polecat Marbled Polecat Pine Marten Otter Lynx Wild Cat Monk Seal Chamois Bottle Nose Porpoise Harbor Porpoise In Bulgaria - 1950 E - U V E V Ex - E E E V In Bulgaria - 1992 R V U V V V Ex U Ex R E E IUCN Red List - V - V - V - - E - - V Priority conservation measures Total number of species concerned Legislative, administrative measures 3 3 0 0 0 1 0 2 0 2 0 0 5 Protected Areas 1 1 1 1 1 1 0 2 0 1 0 0 8 Improvement of Environment 1 - 3 3 2 3 0 1 2 0 2 2 9 Reintroduction or Captive Breeding 0 0 1 2 0 1 3 1 - 1 0 0 6 International Cooperation 0 2 0 0 0 0 3 1 - 0 2 2 5 Research 2 2 3 3 2 2 3 3 1 1 3 3 12 Bibliography
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