Abstract
Eurasian lynx (Lynx lynx) is the most widely distributed felines over Eurasia. Over the whole range this species habitats different types of forest, has a variety of diets (the main two: “mountain” with the predominance of small ungulates and “lowland” – predation on mountain hare) and different population density. Moreover, long-term research showed that density of lynxes may vary significantly in different populations, especially where lynx specialized on hare (for example, centre of European part of Russia, Yakutiya). Population density changes may effect on lynx spatial structure and social relations of the animals. Based on the data obtained in captivity we analysed lynx reproductive success under the different reproductive strategies, relations of the resident and dispersing animals and changes in intralitter relations. Higher density of animals may result in promiscuity mating system in lynx as it is famous for the feral cats. Up to five males may follow one female and try to copulate. Females easily accept the second male for the mating and sperm competition was observed. Multi-male mating result in increase of females reproductive success, partly because of increasing of ovulation rate and partly because of less embryonic losses. It may be explained by the low sperm quality of lynx males. Such way, density increase in lynx population may result to the increase of multi-male mating and to the increase of the reproductive output of the whole population. Resident females mainly aggressive toward the dispersing young however their behaviour depend on the time of dispersion (April or June), sex of the dispersing animal (their were more aggressive to the females) and individual traits of the females. Females detected their own offspring and the behaviour towards them was much more affiliative. Resident animals never chased the dispersing young, so in the wild aggressive relation should not play an important role during the dispersion. Lethal sibling aggression is an extremely rare phenomenon among mammals, but it described at least for two lynx species. Usually these spontaneous fights lead to the strict hierarchical structure in litters and changes in growth rate. If food is scare it may result to the death of the submissive kitten. This phenomenon might have an effect on the survivorship of the kittens. Such way changes in social relations of the individuals may affect reproductive output and survivorship of the lynxes that possibly should be taken to the account estimating population trends.
Other information
The CEES seminar room has a coffee-machine – it is therefore recommended that you come a bit earlier and get yourself a good cup of coffee (for the price of 3 NOK).