A chucao tapaculo, Scelorchilus rubecula (Kittlitz, 1830), plucking hair from a southern pudu, Pudu puda (Molina, 1782), in the Chilean temperate forest

Although the incorporation of mammalian hair in nest construction for thermal insulation has been extensively documented among birds, the kleptotrichy—where birds pluck hair directly from living mammals—remains a relatively underreported behaviour in the scientific literature. Our camera trap monitoring effort in Pumalín Douglas Tompkins National Park, Chile, captured a chucao tapaculo (Scelorchilus rubecula) plucking hair from a southern pudu (Pudu puda). The observed behaviour suggests an adaptation for obtaining nest material, particularly in high-latitude regions like our study area. The pudu's minimal reaction suggests that the hair removal was not perceived as uncomfortable, potentially because the hair was already being shed. This could also be interpreted as a case of ectoparasite removal or other mutualistic interactions. Further research is needed to determine the use of pudu hair as nest construction material and to explain the ecological implications of this behaviour. Our findings highlight the value of camera trap monitoring in expanding the knowledge of species interactions and providing insights about wildlife behaviours.