The foraging strategies of sympatric ungulates with similar ecological niches are important for understanding ecological niche differentiation, resource utilization, competition, and coexistence and for understanding the ecological impacts on plant communities in the ecosystem. The behavior of the wapiti (Cervus elaphus) and Siberian roe deer (Capreolus pygargus) foraging on Japanese yew (Taxus cuspidata) has affected its succession and renewal in the northeastern forests of China, which has become an urgent problem for the relevant departments. This study analyzed the foraging strategies of the wapiti and Siberian roe deer on Japanese yew from July 2021 to January 2024 using field investigations and infrared camera monitoring in the Muling National Nature Reserve, Heilongjiang Province, China. It was found that the wapiti and Siberian roe deer have different foraging strategies in terms of time, space, and behavior. Temporally, they both preferred to forage for the saplings of the Japanese yew during the winter season, the degree of overlap in foraging rhythms was medium (Dhat1=0.67), and the diurnal foraging activity index (DRAI) of the wapiti was larger than that of the Siberian roe deer. Spatially, the suitable foraging habitat of the Siberian roe deer was twice that of the wapiti, and their overlap was low in the location and direction of saplings and the distance of the seed tree. Behaviorally, the foraging intensity of the wapiti was heavy, and Siberian roe deer was low. Foraging reduced the average primary branch height, number of new branches, and length of lateral branches of saplings, and the influence of the wapiti was significantly greater than that of the Siberian roe deer. This study provides a scientific basis for solving the conservation and management problems of the deer animals foraging on Japanese yew and contributes to further understanding of the competition-coexistence mechanism of sympatric species.

Genetic diversity is an important factor reflecting the resistance stability and resilience of species. The prevailing view in population genetics is that species attempt to adopt various strategies to avoid the harms of inbreeding. We speculate that sometimes individuals do not reject mating requests from relatives when choosing mates. Moose (Alces alces cameloides) in the Greater Khingan Mountains (GKM) of China is a first-class key protected species. It represents the southernmost distribution of moose globally and serves as a thermosensitive species of global significance. Based on the state of moose in China, we used a non-invasive sampling method to conduct a series of studies on genetic diversity and inbreeding. The mitochondrial and nuclear genetic diversity of moose in this area are at a moderately high level worldwide, with good individual genetic quality, a high level of overall genotype heterozygosity. The Bayesian gene flow level indicates gene exchange between local populations. Molecular pedigrees revealed instances where individuals mated with their offspring or even grandchildren. The correlation coefficients between moose mating pairs were significantly higher than those of random mating. Therefore, there is no evidence that individuals in the GKM avoid inbreeding, and under these circumstances, there has not been a negative impact on genetic diversity of the moose population, as well as the genetic quality and genotype heterozygosity of offspring. In the context of future climate change and human activities, we need to closely monitor the long-term impact of this mating choice on the survival of the GKM moose population and promptly develop corresponding conservation and management strategies.