Nature Conservation Research: Заповедная наука (Jan 2020)
Comparative analysis of biology and ecology of Glis glis (Gliridae, Rodentia) in the Zhiguli State Nature Reserve (Russia) and adjacent territories
Abstract
The article presents a review of the current state of the Glis glis population in the Zhiguli State Nature Reserve (Russia) and adjacent territories. We present a comparative analysis of biology and ecology of the species with other populations. The Zhiguli G. glis population is the most eastern through the range. It is characterised by numerous peculiarities. Morphometric indicators of G. glis have minimal values here. The average body length of G. glis in the Zhiguli Mts. is 143.8 ± 0.9 mm, length of the tail is 119.6 ± 0.8 mm, length of the rear foot is 28.7 mm (median 29), length of the ear is 18.6 mm (median 18). The body mass of adult individuals is 72.9 g (median 72.3). The lifespan of G. glis is also minimal in the Zhiguli State Nature Reserve. Usually it does not exceed four years. The maximum registered lifespan was 11 years. No significant deviations from 1 : 1 were found in the sexual structure of the G. glis population. The hibernation duration is nine months or more. Juveniles begin hibernating a month or two later than adults. In the study area, G. glis inhabits biotopes with a predominance of Quercus robur, Tilia cordata, Populus tremula, Acer platanoides, with a dense undergrowth formed by Corylus avellana. Glis glis reaches a higher abundance in forests with a predominance of Betula pendula, which is not typical for this species in most of the species range. In accordance, a significant proportion of Betula pendula seeds was found in the nutrition ratio. It increased during the mast years for the Quercus robur, and decreases in non-mast years. The ectoparasite fauna of G. glis is represented by nine species. The main feature of the reproductive cycle of G. glis is mass resorption of embryos at the lack of basic fattening forages. As a result, in most individuals, mating and pregnancy are observed annually, while the birth of pups most often occurs one time per two years. Accordingly, an increase in the population number is observed the next year after a mass reproduction. In reproductively successful years, the litter size ranges from one to eight pups (median 4). The period of postembryonic development is more extended than in other parts of the species range. In litters, there is a very dynamic hierarchical structure based on soft agonistic contacts. There are no clearly defined dominants. We described data on main behaviour types of adults and results of pairings. Identification contacts were the most frequent, followed by agonistic contacts. Benevolent contacts were the rarest. During the activity season, we observed a gradual increase in the level of aggression. However, the aggressiveness of the females sharply decreases after the resorption. An increase in the proportion of benevolent contacts was noted immediately before the hibernation. Thus, the results of the study allowed identifying the interrelated features of biology characteristics in the Zhiguli population of G. glis. To establish its conservation status, comparative studies of other G. glis populations are necessary in European Russia, where the species range has undergone significant anthropogenic transformation.
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