Vertebrate community composition and activity at giant otter latrines in the northern Pantanal

Abstract Mustelids and other terrestrial carnivores use communal latrines where feces and urine serve as olfactory cues for territory demarcation and intraspecific communication. These strong scent cues may also influence the broader vertebrate community, either acting as an attractant for species in search of food or as a warning of predator presence. To investigate these effects, we compared vertebrate diversity, richness, and use characteristics at giant otter ( Pteronura brasiliensis ) latrine sites to background levels within Taiamã Ecological Station and surrounding areas in the Brazilian Pantanal. We deployed 35 motion‐activated camera traps across two sessions from August 2021 to November 2022. Giant otters were observed at 10 camera sites, and we observed the initiation of seven latrines. This allowed us to implement a Before‐After Control‐Impact (BACI) design, comparing each site after latrine initiation to both pre‐latrine initiation and to control sites. Across all sites, we recorded 2593 vertebrate detections, including 743 giant otter records. Species richness was slightly higher at latrine sites, but diversity decreased using indices emphasizing evenness, indicating increased dominance by a few common species. Vertebrate activity, especially among scavenging birds such as southern crested caracaras ( Caracara plancus ), black vultures ( Coragyps atratus ), and lesser yellow‐headed vultures ( Cathartes burrovianus ), increased significantly following latrine establishment. We documented southern crested caracaras consuming feces, sometimes while the otters were still at the latrine, highlighting latrines as transient but important food resources. While community composition did not differ significantly between latrine and control sites, these findings suggest that giant otter latrines can temporarily reshape vertebrate activity patterns and reduce community evenness. As giant otter populations continue to recover, the ecological significance of their latrines may increase, with implications for species interactions and species monitoring in the Neotropics.