Interspeciflc 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.