Возрастная структура популяции азиатского бурундука (Tamias sibiricus) в Северном Приохотье

The age-related variability of the abrasion degree of the masticatory surface of the first lower molar in the Northern Priokhotye population of the Siberian chipmunk has been studied. It has been revealed that, in young of the current year, from the time they abandoning breeding burrows to the hibernation period, the index of abrasion of the masticatory surface m1 is 0.6-3.5 %. The area of exposed dentin on the molar masticatory surface increases annually by 5-6 % averagely in overwintered adult animals. According to the abrasion index, 4-5 age classes are distinguished in the population. The group of animals aged 1+ yrs dominates in number (40.8 %). The specific survival rate of individuals in the range from 1 to 3 years is approximately 0.5. After three years, it drops sharply (0.23). Less than 3 % of individuals survive up to 4 years or more in the population.

LARVAE OF NEOTROMBICULA TALMIENSIS (SCHLUGER, 1955) (ACARIFORMES, TROMBICULIDAE) AND THEIR FEATURES PARASITISM ON NATURAL HOSTS

Parasitengonina mites being a highly diverse and specialized phyletic lineage of the higher Acariformes, possess small and simply organized larvae. These larvae show a highly effective feeding mode of the proteinaceous feeding substrate consisting of the pre-oral digested host tissues. This capability is a result of the stylostome formation and allows larvae to overcome easily a high ontogenetic threshold between the larval organization and that of post-larval phases. Larvae of N. talmiensis evolve an identically organized pale-pink stylostome during feeding on both bank voles and Siberian chipmunk that confirm a hypothesis of the genus- or even species-specific stylostome organization.

Endozoochory by granivorous rodents in seed dispersal of green fruits

Although the role of frugivores in seed dispersal has attracted scientific attention, it remains unclear whether granivorous rodents can act as frugivores to interact mutualistically with fruit-producing plants, especially those bearing green fruits inconspicuous to avian frugivores. In this study, we tracked fruit removal of the tara vine (Actinidia arguta (Siebold & Zucc.) Planch. Ex Miq.) and variegated kiwi vine (Actinidia kolomikta (Rupr. & Maxim.) Maxim.) in a temperate forest and presented fruits to the granivorous rodents Siberian chipmunk (Tamias sibiricus (Laxmann, 1769)), Korean field mouse (Apodemus peninsulae (Thomas, 1907)), and gray red-backed vole (Clethrionomys rufocanus (Sundevall, 1846) = Myodes rufocanus (Sundevall, 1846)) in the laboratory to answer this question. Seeds were collected from rodent feces to see the effects of gut passage on seed germination to determine the role of granivorous rodents in endozoochory of A. arguta and A. kolomikta. We presented clear evidence of endozoochory by granivorous rodents in seed dispersal of the two Actinidia species. Rodents appeared to play an alternative role in dispersing plants bearing green fruits. Moreover, we observed increased germination rates after gut ingestion by the granivorous rodents. Our study evidenced endozoochory of granivorous rodents and provided new insight into the mutualist interactions between rodents and plant species bearing fleshy fruits containing tiny seeds. We suggest future studies pay more attention to endozoochory of rodents and establish their mutualistic relationship with fruit-bearing plants in temperate forests.