Demography of the Giant Otter (Pteronura brasiliensis) in Manu National Park, South-Eastern Peru: Implications for Conservation

A study on the giant otter (Pteronura brasiliensis) population in Manu National Park, Peru, reveals critical insights into its slow recovery from historical hunting pressures. The research, spanning 16 years with annual dry-season censuses, found that the species' breeding system—characterized by a single reproductive female and non-reproductive helpers—combined with physiological traits like late reproduction and long generation times, results in a low intrinsic rate of increase (0.03). High mortality rates, particularly among dispersers, further hinder population growth. The study also highlights the importance of female dominance tenure duration for reproductive success and notes that immigrant males pair with sisters or daughters upon breeding female death. These findings underscore the vulnerability of giant otters to anthropogenic disturbances, emphasizing the need for robust protection of core lake habitats and riverine forests, which are under severe threat from gold mining, logging, and agriculture in the Madre de Dios region.

Groenendijk, J., Hajek, F., Johnson, P. J., Macdonald, D. W., Calvimontes, J., Staib, E., & Schenck, C. (2014). Demography of the Giant Otter (Pteronura brasiliensis) in Manu National Park, South-Eastern Peru: Implications for Conservation. PLoS ONE, 9(8), e106202. https://doi.org/10.1371/journal.pone.0106202