Research on the evolution of dog foraging and diet has largely focused on scavenging during their initial domestication and genetic adaptations to starch-rich food environments following the advent of agriculture. The Siberian archaeological record evidences other critical shifts in dog foraging and diet that likely characterize Holocene dogs globally. By the Middle Holocene, body size reconstruction for Siberia dogs indicates that most were far smaller than Pleistocene wolves. This contributed to dogs’ tendencies to scavenge, feed on small prey, and reduce social foraging. Stable carbon and nitrogen isotope analysis of Siberian dogs reveals that their diets were more diverse than those of Pleistocene wolves. This included habitual consumption of marine and freshwater foods by the Middle Holocene and reliance on C ₄ foods by the Late Holocene. Feeding on such foods and anthropogenic waste increased dogs’ exposure to microbes, affected their gut microbiomes, and shaped long-term dog population history.

To assess the trophic position of the exceptionally large-sized brown bears from the Pleistocene of Yakutia, we used stable nitrogen and carbon isotope analyses of the collagen contained in fossil bones and teeth. Modern brown bears of Yakutia were compared to the large Pleistocene predators. As a result of the measurements taken for the Pleistocene bears, we obtained δ¹³С values typical of terrestrial ecosystems and relatively high δ¹⁵N values typical of such Pleistocene predators as the cave lion. We explain the high δ¹⁵N values of the bone collagen of the study fossil bears, as well as other Pleistocene brown bears of Yakutia and Chukotka, by (1) the absence of large competitors such as Arctodus simus, which allowed the bears to use large amounts of animal food; (2) the physiological effect of hibernation, expressed in an increased content of ¹⁵N in the bone collagen; and (3) an increased content of ¹⁵N in vegetation due to more severe climatic conditions, which affects the isotopic composition of the entire mammoth fauna of western Beringia. The δ¹³C and δ¹⁵N values of modern brown bears in Yakutia indicate a plant diet, suggesting that the modern brown bears (compared to fossils) occupy a fundamentally different trophic niche adapted to the modern low-productivity ecosystems of Yakutia.

The Aleutian Islands comprise a unique ecosystem, providing nesting grounds and habitat for more than ten million seabirds. No doubt their numbers were even larger prior to the introduction of foxes and rats, invasive species that have shaped the current population sizes and distributions of bird-breeding colonies. Here we present evidence that the peopling of the Aleutian Islands had the same dramatic effect on seabird populations. Analyses of nitrogen stable isotopes in Shemya Island peat deposits revealed significant ¹⁵N enrichment of layers formed cal. 4,700–2,800 yrs BP suggesting high seabird guano input at that time. Following this period there was a sharp decline in δ¹⁵N that coincides with the first appearance of human settlement and reflects drastic reduction in seabird abundance. The isotope signature of marine-derived nitrogen vectored by seabirds is specific only for coastal peat deposits; neither ¹⁵N enrichment nor decline was detected in inland peat deposits.

Data on the first reliable findings of subfossil remains of the black rat in north-western Russia (Vologda and Vladimir oblasts) are given. The burying of the remains dates to the twelfth to thirteenth centuries. It is assumed that the spread of the black rat in the European part of Russia in the Middle Ages was associated first of all with the development of trade.

Изучение изотопного состава углерода и азота в современных природных сообществах помогает создавать палеоэкологические реконструкции ландшафтного окружения и пищевых ресурсов средневекового сельского