Feeding behavior and trophic niche partitioning between co-existing river otter species

• Published in: Hydrobiologia 2021-10, Vol.848 (18), p.4167-4177
• Main Authors: Moraes, Carine G., Hegg, Jensen, Giarrizzo, Tommaso, Andrade, Marcelo C.
• Format: Article
• Language: English
• Subjects: Animal behavior; Behavior; Biomedical and Life Sciences; Competition; Conservation; Diet; Ecology; Endangered & extinct species; Feeding behavior; Feeding habits; Females; Fish; Freshwater & Marine Ecology; Freshwater mammals; Habitats; Hydroelectric plants; Hydroelectric power; Hydroelectric power plants; Hydrologic regime; Hydrology; Life Sciences; Mammals; Mustelidae; Niche (Ecology); Niche breadth; Niche overlap; Niches; Otters; Partitioning; Population decline; Population studies; Populations; Prey; Primary Research Paper; Protected areas; Rainy season; Rivers; Seasons; Species; Species diversity; Wet season; Wildlife conservation; Zoology
• ISSN: 0018-8158; 1573-5117
• DOI: 10.1007/s10750-021-04614-w

Niche partitioning occurs among coexisting populations to reduce the effects of competitive exclusion among species of similar niche. The aim of the present study is to verify the trophic niche partitioning and feeding behavior between two mustelids, the Giant otter and the Neotropical otter, through the dry and rainy season hydrologic of the Lower Xingu River. Our results suggest that the diets of both mustelids are composed primarily of fish of the family Anostomidae (Headstanders). Despite extensive niche overlap, our results indicate partitioning is facilitated by differences in niche breadth, with potential implications for conservation of both species in the case of declines in prey abundance and diversity. Both species inhabit an area recently impacted by completion of the Belo Monte Hydropower Plant, resulting in large changes to the hydrologic regime. Thus, our results provide important information for conservation efforts regarding the feeding behavior and co-occurrence of both species, as well as providing a baseline for monitoring future health of these mustelid populations. The present study is the first to test the hypothesis of niche partitioning between these two mustelids outside a protected area in the Amazon.