Elwira Szuma

Dental polymorphism in a population of the red fox (Vulpes vulpes) from Poland

Dental polymorphism in a population of the red fox Vulpes vulpes (L.) from Poland was studied in a sample of 1453 specimens (637 males, 535 females and 281 specimens of unknown sex). Frequency distributions in 15 groups of morphotypes (A–O) were analysed and a pattern of qualitative features was constructed on the ground of frequency analysis of particular morphotypes. An increase in complication of tooth shape of the carnassial region (P4, P4, M1, M1), as well as higher morphological variation of the teeth from borders of the cheek rows (P1, P1, M2, M3) were ascertained. Almost all groups of morphotypes, excluding three, presented absence of significant sexual differences. The pattern of qualitative features was used to verify an existing model of genetic control of evolutionary changes in dental morphology of mammals. Positive, statistically significant relationships between the dental size and presence or degree of formation of the dental structures confirmed the operation of the size-related mechanism, i.e. threshold mechanism, during ontogeny.

Evolutionary implications of morphological variation in the lower carnassial of red foxVulpes vulpes

Research on the morphological variability of the occlusal surface of M1 talonid in the red foxVulpes vulpes (Linnaeus, 1758) in the Holarctic has been carried out on 2271 specimens originating from 42 populations. The Nearctic was represented by 666 specimens belonging to 13 populations, whereas Palearctic was represented by 1605 specimens from 29 populations. Analyses of the developmental level and formation of cristids between the hypoconid and entoconid allowed the differentiation of 34 shape variants of the occlusal surface of the talonid in the red fox. Because of the complicated variation of cristids, 34 variants were assigned to 5 morphotypes of group P. In the Palearctic and Nearctic a significant geographic variation occurred of P morphotypes and their variants. Primitive variants of the talonid structure on M1 are predominant in populations from the south of the Asian range of the red fox, while more progressive characters of the occlusal surface of the lower carnassial are typical of the northern and centrally located red fox populations in the Palearctic and Nearctic. The geographic differentiation is probably connected with different Pleistocene histories of particular populations.

Erratum to: Evolutionary and climatic factors affecting tooth size in the red foxVulpes vulpes in the Holarctic

Research into the geographical pattern of tooth size in the red fox,Vulpes vulpes (Linnaeus, 1758) in the Holarctic was conducted on a sample of 3806 skulls belonging to 41 fox populations. The Nearctic was represented by 948 specimens (249 females, 359 males, 340 specimens of unknown sex) belonging to 13 populations, whereas the Palearctic was represented by 2858 red foxes (1034 females, 1256 males, 568 specimens of unknown sex) from 32 populations. In the Nearctic, the largest foxes live on Kodiak Island (V. v. harrimani) and the Kenai Peninsula (V. v. kenaiensis), while the smallest ones live in California (V. v. necator) and Georgia (V. v. fulvus). In the Palearctic, the largest foxes come from the Far East (V. v. jakutensis, V. v. beringiana, V. v. tobolica), while the smallest are from the southern borders of the Eurasian range (V. v. pusilla, V. v. barbara, V. v. arabica). In both the Palearctic and Nearctic, tooth size in the fox varies depending on the geo-climatic factors. The fox’s tooth size confirms the general basis of Bergmann’s rule. In the Palearctic, specimens with larger teeth occur in cooler habitats with greater seasonality. These are first and foremost Northern and Far Eastern populations. In the Nearctic, tooth size in red foxes depends on the temperature and humidity of their habitat. Competition within the species and between species has important impact on the variation and dimorphism of tooth size in the red fox. Both in the Nearctic and Palearctic, red foxes from regions of sympatric co-occurrence with other closely relatedVulpes species, are more sexually dimorphic in terms of tooth size than red foxes from allopatric regions. Analysis of morphological distance on the basis of the size of dental characteristics shows, that in the Palearctic, the foxes from India (V. v. pusilla), while in the Nearctic, the population from Kodiak Island (V. v. harrimani) are most distant from the remaining populations. Geographic barriers such as the Bering Strait, Parry Channel, Mackenzie River, Kolyma and Omolon River systems have had a critical impact on red fox evolution. The most likely place for the evolution and diversification of the phyletic lineVulpes vulpes seems to be the Middle East region.

Ecological and Evolutionary Determinants of Dental Polymorphism in the Arctic Fox Vulpes (Alopex) lagopus

The influence of some ecological and evolutionary factors on the pattern of dental polymorphism across the geographic range of the arctic fox (Vulpes (Alopex) lagopus) was studied. Dental morphotype characters (groups of morphotypes from A to S) in 12 geographically separate populations of the arctic fox were documented. Two evolutionary trends were observed: (1) simplification of the premolars and lower carnassial (M1), and (2) increased complexity of the upper carnassial (P4), third upper incisor (I3), and third lower molar (M3). Differences in dental morphology among arctic fox populations appear to be largely explained by evolutionary history, presence or absence of competition with the red fox (Vulpes vulpes), and diet, with a lesser influence of geography and climate. With respect to morphology, arctic foxes from the mainland populations of Eurasia and North America, are the most similar, followed by the partly-isolated island populations (Greenland, St. Lawrence Island). The most distinct forms are the arctic foxes from Commander Islands, that exist in permanent isolation.

Morphometric variation of the skull during postnatal development in the Lowland European bisonBison bonasus bonasus

We studied the variation of linear measurements and skull capacity in Lowland European bisonBison bonasus bonasus (Linnaeus, 1758) during postnatal development, and the dependencies of the parameters in relation to sex, age, and body mass of the animals. Material consisted of 599 bison skulls (310 males and 289 females), within the age range of 1 month to 21 years (males) and to 27 years (females). In the group of calves to 1 year old, no sex connected differences in skull measurements were observed, whereas the skull capacity in older calves was significantly larger (0.01>p>0.001) in males than in females. From the third year of life, most skull measurements display characteristics of sexual dimorphism. Skull development in both sexes is most intensive during the first three years of life, and slows from the age of 5. In older individuals of both sexes (≥ 6 years), orbital breadth continues growing and, in females, breadth of splanchnocranium continues increasing. Growth in a bison’s skull capacity is most intensive up to the third year of life and slows from the age of 5. During postnatal development, a bison skull grows proportionally except the neurocranium, which grows slightly slower in comparison with basal length and its development finishes earlier than that of splanchnocranium. In ontogenesis, a bison skull grows much slower compared to body mass. In relation to body mass, skull capacity and the height of neurocranium grow most slowly while orbital breadth grows most intensively. The results obtained were compared with data on skull sizes of bison born in 1930–1950 and bred in captivity and with skulls of the American bisonBison bison. Inbreeding is probably responsible for some types of phenotypic abnormalities in the skull which appear in modern European bison.

Dental polymorphism of the raccoon dog in indigenous and invasive populations: internal and external causation

In total, 721 specimens from eight populations of the raccoon dog Nyctereutes procyonoides across native and colonized areas have been studied. The most polymorphic populations inhabit the European part of Russia and a part of the native area. The raccoon dog from Eastern Poland and the Primorie Far East is characterized by low intrapopulational variability. Quantitative genetic variations in the studied populations indicate a relatively higher level in the population from the Primorie Far East compared to the Southern Vologda and Eastern Poland. The pattern of morphological variability in the raccoon dog is shaped by such factors as the latest phylogenetic history of the species and the structure of the morphotype frequency in the time of the divergence of the populations on both micro-and macro-geographic levels. The influence of geographic and climatic factors forms a well-pronounced trend towards diversification in tooth morphology, which is most probably the consequence of adaptations to changes in the food niche.