The colour phases of the European red squirrel in Ukraine: Similarities and differences by craniometric characters
AbstractThe different colour phases of the European red squirrel occuring in Ukraine were analysed in a morphological context. They are indicated in the literature as different subspecies of Sciurus vulgaris L. and described only based on their coat colouration. In Ukraine, at least three colour phases occur: dark (black and brown), red, and light red, which in natural habitats occur separately from one another. These phases co-occur in human settlements and at different altitudes, in particular at the boundary of the lowland and piedmont zones and of piedmont and mountainbelts. The aim of the present study was to find some other morphological differences between the red squirrel’s phases in Ukraine beyond their coat colouration and to reveal the possible interaction between colouration and morphological variation of the squirrels. Eighteen craniometric and four external characters were measured and analysed. Results have shown that the squirrel’s colour phases differ among themselves by some characters, although the most visible differences were revealed when all measurents were analysed together. It has been revealed that the three colour phases are stabilized types (populations) manifested in a multidimensional space as different populations with minimal overlap (up to 10%). The population of dark squirrels in Ukraine is morphologically the most distant from the light red phase and less so from the red one. The dark phase significantly differs from the red phase by 9 of 18 craniometric characters with Mayr’s coefficient of divergence (CDmin = 0.62, CDmax = 0.96). The dark phase significantly differs from the light red phase by two craniometric characters according to ANOVA, but only by one character according to Mayr’scoefficient of divergence (CD = 0.96). The red and light red phases significantly differ by four parameters having CDmin = 0.64 and CDmax = 0.76. The geographically transitional red phase is morphologically intermediate according to the results of discriminant analysis.
Barratt, E. M., Gurnell, J., Malarky, G., Deaville, R., & Bruford, M. W. (1999). Genetic structure of fragmented populations of red squirrel (Sciurus vulgaris) in the UK. Molecular Ecology, 8(12), 55–63.
Bilokon, S., Belokon, M., Belokon, Y. U., & Dykyy, I. (2014). Minlyvistʹ vyvirky zvychaynoyi (Sciurus vulgaris L.) Zakhodu Ukrayiny za mikrosatelitnymy lokusamy [Genetic diversity of Red squirrel (Sciurus vulgaris L.) from Western Ukraine by SSR loci]. Visnyk of the Lviv University. Series Biology, 65, 296–305 (in Ukrainian).
Bosch, S., & Lurz, P. W. W. (2012). The Eurasian Red Squirrel Sciurus vulgaris. Westarp & Partner Digital druck Hohenwarsleben UG, Germany.
Cott, H. B. (1940). Adaptive colouration in animals. Methuen & Co., Ltd., London.
Grill, A., Amori, G., Aloise, G., Lisi, I., Tosi, G., Wauters, L. A., & Randi, E. (2009). Molecular phylogeography of european Sciurus vulgaris: Refuge within refugia? Molecular Ecology, 18(12), 2687–2699.
Hale, M. L., Lurz, P. W. W., & Wolff, K. (2004). Patterns of genetic diversity in the red squirrel (Sciurus vulgaris L.): Footprints of biogeographic history and artificial introductions. Conservation Genetics, 5, 167–179.
Koh, H. S., Bayarkhagva, D., Kryukov, A., Zhang, M., Lee, B. K., Bazarsad, D., & Ho, S. W. (2015). A study on genetic divergence of the red squirrel Sciurus vulgaris (Rodentia: Mammalia) from six regions in Eurasia: Based on cytochrome b complete sequences. Acta Zoologica Academiae Scientiarum Hungaricae, 61(4), 361–372.
Madsen, C. L., Vilstrup, J. T., Fernández, R., Marchi, N., Håkansson, B., Krog, M., Asferg, T., Baagøe, H., & Orlando, L. (2015). Mitochondrial genetic diversity of eurasian red squirrels (Sciurus vulgaris) from Denmark. Journal of Heredity, 106(6), 719–727.
McDonald, J. H. (2014). Handbook of Biological Statistics (3rd Ed.). Sparky House Publishing, Baltimore.
Miller, G. S. (1912). Catalogue of the mammals of Western Europe (Europe exclusive of Russia) in the Collection of the British Museum. British Museum (Natural History). Department of Zoology [Mammals], London.
Sidorowicz, J. (1958). Geographical variation of the squirrel Sciurus vulgaris L. in Poland. Acta Theriologica, 2, 142–157.
Sidorowicz, J. (1961). Craniometrical measurements of Scandinavian Squirrels and their distribution. Acta Theriologica, 17, 153–161.
Trizio, I., Crestanello, B., Galbusera, P., Wauters, L. A., Tosi, G., Matthysen, E., & Hauffe, H. C. (2005). Geographical distance and physical barriers shape the genetic structure of Eurasian red squirrels (Sciurus vulgaris) in the Italian Alps. Molecular Ecology, 14(2), 469–481.
Wauters, L. A., Hutchinson, Y., Parkin, D. T., & Dhondt, A. A. (1994). The effects of habitat fragmentation on demography and on the loss of genetic variation in the red squirrel. Proceedings: Biological Sciences, 255, 107–111.
Zagorodniuk, I. (2007). Konflikt cherez zbih nish u vydiv-dviynykiv: Otsinka za staloyu khatchinsona [Conflict through coincidence of niches in sibling species: Estimation using Hutchinsonian ratio]. Scientific Bulletin of the Uzhhorod University. Series Biology, 20, 5–13 (in Ukrainian).
Zagorodniuk, I. (2012). Study of osteological samples of mammals: Key craniometric characters. Proceedings of the Theriological School, Variability and Ecology of Mammals, 11, 16–32 (in Ukrainian).
Zawidzka, E. (1958). Geographical distribution of the dark phase of the squirrel (Sciurus vulgaris fuscoater Altum) in Poland. Acta Theriologica, 2, 160–174.
Zizda, Y. (2005). Poshyrennya kolʹorovykh form vyvirky (Sciurus vulgaris) u Zakarpatti ta v sumizhnykh oblastyakh Ukrayiny [Distribution of the coloured phases of squirrel (Sciurus vulgaris) in the Transcarpathians and adjacent regions of Ukraine]. Scientific Bulletin of the Uzhhorod University. Series Biology, 17, 147–154 (in Ukrainian).
Zizda, Y. (2008). Minlyvistʹ zabarvlennya khutra ta analiz poshyrennya riznykh pidvydiv Sciurus vulgaris [Changeability of fur colouring and analysis of different subspecies of Sciurus vulgaris distribution]. Scientific Bulletin of the Uzhhorod University. Series Biology, 22, 179–185 (in Ukrainian)