First Data on Nutrition of the Ural Cave Bear Ursus (Spelaearctos) kanivetz Verestchagin, 1973 (Mammalia, Carnivora, Ursidae) as Based on 13C and 15N Isotope Analyses

Content of 13С and 15N Isotopes in Bone Collagen of Geographical, Age, and Sex Groups of the Ural Cave Bear (Mammalia, Carnivora, Ursidae, Ursus (Spelaearctos) kanivetz Verestchagin, 1973)

Data on the content of 13C and 15N isotopes in the collagen of bones of the Ural cave bear (Ursus (S.) kanivetz Verestchagin, 1973) from the North and Middle Urals were analyzed. The bones date from the first half of MIS 3. The bones of newborn individuals, individuals aged 1 year, males and females aged 2, 3, and 4 years, and older than 4 years were studied. Differences in δ13С values between age, sex, and geographical samples are not significant. With age, the value of δ15N significantly decreases, which is associated with weaning from milk nutrition to independent nutrition. The proportion of meat food in the diet of adult bears in the Middle Urals was higher than in the diet of adult bears in the North Urals. There are no noticeable differences in isotope signatures between males and females of different ages. The large cave bears of the Urals and Europe had a similar type of diet.

Diet of the Small Cave Bear Ursus (Spelaearctos) rossicus Borissak, 1930 (Mammalia, Carnivora, Ursidae) As Revealed by 13C and 15N Isotope Analyses in Bone Collagen

The 13C and 15N isotope contents in bone collagen were analyzed using bones of the small cave bear Ursus (Spelaearctos) rossicus Borissak, 1930 from localities in the Middle and Southern Urals. The bones date from the last interglacial (MIS 5) and glacial (MIS 3) periods. The bones were from males and females aged 3, 4, and >4 years. Sexual, geographical, and chronological differences in 13C and 15N contents were studied. Notable gender, geographic, and chronological differences were observed between samples. In the Middle Urals, females led a more predatory lifestyle than males during the interglacial period, and the trophic niches of males and females converged due to an increase in herbivory during the transition to the glacial period. In the Southern Urals, males led a more predatory lifestyle than in the Middle Urals during the interglacial period. The extent of changes in δ13C and δ15N values in the Southern Urals during the transition was found to correspond to differences between trophic levels.