Impact of sympatric carnivores on den selection of wild giant pandas

Interspecific killing is a primary reason for the low survival rates of some animal species. The giant panda(Ailuropoda melanoleuca) is an altricial eutherian mammal and thus, in comparison to other infants, panda cubs are highly vulnerable, which may significantly influence the selection of breeding sites by females. Here, we used infrared camera traps to monitor giant panda dens for 5.5 years in Foping National Nature Reserve(FNNR) to determine how interspecific factors affect den selection by wild female pandas. Results indicated that Asian black bears(Ursus thibetanus), yellow-throated martens(Martes flavigula), leopard cats(Prionailurus bengalensis), and masked palm civets(Paguma larvata) visited the dens frequently, and the presence of these species negatively influenced den selection by female pandas. Interestingly, the presence of rodents and terrestrial birds appeared to indicate den safety, and female giant pandas were not averse and even preferred dens with a high abundance index of rodents and terrestrial birds. The den suitability index(DSI) was a reliable tool for evaluating whether dens were suitable for female giant pandas to give birth to and rear cubs, with preference for dens with high DSI values. This study increases our understanding of the den selection criteria of female giant pandas and the main threats to the survival of their cubs,thus providing important guidance for the conservation and management of this species.

Stable seasonal migration patterns in giant pandas

A critical function of animal movement is to maximize access to essential resources in temporally fluctuating and spatially heterogeneous environments.Seasonally mediated resource fluctuations may influence animal movements,enabling them to track changing resource distributions,resulting in annual migration patterns.The conservation-dependent giant panda(Ailuropoda melanoleuca) displays seasonal movement patterns;however,the key factor driving these seasonal migration patterns remains poorly understood.Here,we used GPS tracking collars to monitor the movements of six giant pandas over a 12-year period across different elevations,and performed statistical analysis of seasonal migration directions,routes,habitat revisitation,home range overlap,first arrival events,and stability.Our results revealed a compelling pattern of seasonal migrations that facilitated the ability of the pandas to forage at the appropriate time and place to maximize nutritional intake.Our results indicated that pandas utilize spatial memory to locate reliable food resources,as evidenced by their annual return to the same or similar winter and summer home ranges and the consistently maintained percentage of home range overlap.These novel insights into giant panda foraging and movement ecology not only enhance our understanding of its ability to adapt to nutritionally poor dietary resources but also provide important information for the development of resource utilization-based protection and management strategies.

Identifying priority protection areas of key food resources of the giant panda

Animals that live in seasonal environments adjust their reproduction cycle to optimize seasonal forage quality.Giant pandas(Ailuropoda melanoleuca)are seasonal altitudinal migrants that feed on bamboo shoots and leaves with different nutritional quality.However,the importance of bamboo shoots to giant pandas,especially small and isolated populations,is not fully appreciated.Here,we explored whether mating time of giant pandas is shaped by bamboo shoot phenology.We also assessed the intensity of ongoing bamboo shoot harvesting by local communities in 42 giant panda reserves based on questionnaire surveys.Varying intensity and protection levels of bamboo shoot harvesting were found.From these data,we developed a priority ranking scheme of protection areas for this key food resource.Our study showed that pandas time their mating behavior to coincide with bamboo shoot phenology due to the high nutritional demands associated with mating and pregnancy.We also found that bamboo shoots were not well protected in many places.Liangshan,Daxiangling,and Xiaoxiangling,containing the most isolated panda populations,were identified as the areas with the most urgent need of protection.Furthermore,equal attention should be paid to the Qiong L-B population,as this region holds considerable potential to serve as a corridor between the Minshan and Qionglai populations.To address the challenges posed by bamboo shoot harvesting,we recommend establishing more practical bamboo shoot management policies,increasing public awareness of bamboo shoot protection,and providing alternative sources of income for local communities.