Nevertheless, tropical forests can experience considerable seasonality in leaf flushing and fruiting as a response to climatic variables ( Mendoza, Peres & Morellato, 2016). However, the seasonality of predator–prey relationships in tropical forests is at best considered to be subtle compared with temperate and boreal regions, because of the comparatively low variation in day length and ambient temperature ( Forsythe et al., 1995).

Both the nature and magnitude of predation as a dominant ecological force are affected by seasonality ( Darimont & Reimchen, 2002). Predation is a central theme in ecology and evolution, driving morphological, physiological, and behavioural responses in prey species to the threat of death or injury ( Genovart et al., 2010). The seasonal eﬀects shown here suggest important demographic consequences for sloths, which are under top-down regulation from harpy eagle predation, perhaps limiting their geographic distribution at higher latitudes.

Therefore, predator–prey ecology in the tropics can be modulated by subtle changes in environmental conditions. We showed that even moderate seasonal variation in temperature can influence the relationship between a keystone tropical forest predator and a dominant prey item. We suggest that the first ensured low detectability conditions for sloths foraging at night and the second posed a thermally unsuitable climate that forced sloths to forage under riskier daylight. bright moonshine) and positively aﬀected by seasonally cool temperatures. Here we show that sloth predation by harpy eagles was negatively aﬀected by nocturnal ambient light (i.e. We analysed the effects of climatic conditions and vegetation phenology on the prey species profile of harpy eagles using generalised linear mixed models. For each predation event, field assistants systematically recorded the species killed. Telemetered harpy eagles were seen hunting and feeding on individual prey species. Our study was conducted between 20 at Soberanía National Park, Panamá. This eﬀort incidentally enabled us to understand the prey profile of harpy eagles over multiple seasons. This motivated a comprehensive eﬀort to reintroduce this species into parts of Mesoamerica. The harpy eagle is considered Near Threatened. Yet the role of environmental variables on the regulation of predator–prey interactions between sloths and harpy eagles are unknown. The harpy eagle ( Harpia harpyja) is a sloth-specialist and exerts strong top-down control over its prey species. Sloths are largely or strictly nocturnal, and depend on crypsis to avoid predation. In tropical forests, sloths are the arboreal vertebrate attaining the greatest biomass density, but their capacity to regulate body temperature is limited, relying on behavioural adaptations to thermoregulate.

For species with limited ability to control core body temperature, even mild climatic variation can determine major behavioural outcomes, such as foraging and predator avoidance. However, tropical forests are only weakly seasonal compared with temperate and boreal regions. PeerJ 8: e9756 Ĭlimate plays a key role in the life histories of tropical vertebrates. High moon brightness and low ambient temperatures affect sloth predation by harpy eagles. Cite this article Miranda EBPd, Kenup CF, Campbell-Thompson E, Vargas FH, Muela A, Watson R, Peres CA, Downs CT. For attribution, the original author(s), title, publication source (PeerJ) and either DOI or URL of the article must be cited. Licence This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. 6 Departamento de Sistemática e Ecologia, Universidade Federal da Paraíba, João Pessoa, Brazil DOI 10.7717/peerj.9756 Published Accepted Received Academic Editor David Nelson Subject Areas Animal Behavior, Conservation Biology, Ecology, Zoology Keywords Bradypus, Canopy, Choloepus, Foraging, Seasonality, Apex predator, Tropical forest, Deciduousness, Moonlight, Harpia harpyja Copyright © 2020 Miranda et al.

Sloth predators