On the Pine marten (Martes martes) morphology in the Upper Ob River basin

Abstract

Over a period of about 30 years, a new population has appeared in the area of the pine marten. This grouping of species is formed by a natural expansion of animals from the adjacent territories of Novosibirsk region or Kazakhstan. The animal inhabited areas unusual for it: pine forests and adjacent birch-aspen woods in the plain forest-steppe of the south-eastern part of Altai Krai (See Fig. 1). The first marten traces were recorded in the mid-1980s near Shadrukha village in Uglovskiy district. The first animal was caught in 1988 in the vicinity of Novo-Uglovskoe village. In 2013, the first population counts were carried out revealing 383 martens. 2249 martens lived in the region in the spring 2019. The newly formed group is poorly studied in zoological terms, and we make an attempt to eliminate this omission. We studied the first representative pine marten hunting sample obtained in 2016- 2019 from the Altai ribbon pine forest population (Barnaul band, 52°42ꞌN and 82°10ꞌE). We applied the classical zoological techniques used during collecting the biological materials (incomplete anatomical autopsy, measuring animal body and its parts, preparation of craniological collection samples). The average popultion parameters of the marten grouping were obtained and studied: body length, tail length, baculum length, 17 craniometric traits for males and females (See Tables 1 and 2). The age of animals was determined by the method of Timofeev-Nadeev (1955) on the development of sagittal and occipital crests on the frontal and parietal bones of the skull. For all mean values, basic statistics was calculated (Х ± m х and CV). Differences were taken as statistically significant at the level of 5% (p < 0.05). Difference testing and cluster analysis of craniometric data (UPGMA, unweighted method of pairwise average) were  carried out in Stat Soft STATISTICA 8.0 package. To assess sexual dimorphism, we used the I SD indicator proposed by Rossolimo and Pavlinov (1974): I SD = 100(X♂–X♀)/ X♀, where: ISD is the value (ISD index) of sexual dimorphism, expressed as a percentage; X♂ and X♀ are the mean values of traits for males and females, respectively. As a result of our research we established that the mean values of the studied morphological traits of adult martens from the Altai ribbon pine forest population are as follows: body length 43.95 mm, tail length 22.35 mm in males and 40.2 and 20.12 in females, respectively; the length of the baculum (8 males) 43.04 mm; condylobasal skull length 84.5 mm in males and 77.7 mm in females. The obtained data were compared with the characteristics of some of East and West European populations of the species, information about which was found in literary sources (See Tables 3 and 4). A cluster analysis of 17 populations by skull size showed (See Fig. 2) that Altai pine martens are classified into same cluster with large martens from the Caucasus and Lithuania, exceeding in size many of East European populations with a condylobasal skull length of less than 83.5 mm in males and 76.5 mm in females. At the same time, Altai pine martens are smaller in body and skull sizes than West European martens which have a condylobasal skull length of more than 85 mm in males and 78 mm in females, making up cluster A in the dendrogram of Fig. 2. We consider the question of the intraspecific taxonomic status of the new population without analyzing data on the color and other properties of the fur coat to be premature. The study of the indices of sexual dimorphism of the exterior (7.25-8.31%) and craniometric characteristics (8.11% on average for 17 traits and 8.77% for the condylobasal length of the skull) allows us to conclude that the animals of the new population do not show noticeable differences in this parameter from other groupings of the species range. A thirty-year old history and a continuous increasing in the number of the newly formed pine marten population in the east of the range allows to expect a further strengthening of this grouping. This will create the preconditions for the formation of new foci of sympatry in Altai Krai and in adjacent territories where the sable and pine marten will inhabit. The paper contains 2 Figures, 4 Tables and 29 References. The Authors declare no conflict of interest. No animal was caught for the purposes of this study. Animals were hunted by legal hunters using humane methods of catching