Insights into the development of a juvenile harpy eagle’s hunting skills

Abstract

The post-fledging period is of paramount importance for raptors, since this is when a juvenile develops its hunting skills and gains the abilities required in adulthood and independence through dispersal. Little is known however, about this stage in the lives of raptors such as harpy eagles, Harpia harpyja. Between March 2016 and July 2017, we recorded three predation attempts on groups of primates by a wild juvenile harpy eagle in southwestern Brazilian Amazonia, including the first predation of an adult squirrel monkey, Saimiri ustus. These sequential records give insights into the gradual development of hunting skills during the post-fledging period, similar to what has been reported for other birds of prey. We hypothesize that a link between developing flight skills, decreasing parental food provisioning and increasingly successful captures triggers adulthood and independence in harpy eagles. Considerações sobre o desenvolvimento da habilidade de caça de um gavião-real juvenil RESUMOO período pós-emplumagem é de suma importância para os rapinantes, pois é quando um jovem desenvolve a habilidade de caça necessária na idade adulta e a independência por meio da dispersão. Entretanto, pouco se sabe sobre esse estágio na vida de rapinantes como o gavião-real, Harpia harpyja. Entre março 2016 e julho 2017, três tentativas de predação sobre grupos de primatas por um gavião-real juvenil foram registradas no sudoeste da Amazônia brasileira, incluindo a primeira predação de um macaco-de-cheiro adulto, Saimiri ustus. Estes registros sequenciais indicam um desenvolvimento gradual da habilidade de caça ao longo do período de pós-emplumagem, de forma similar ao relatado para outros rapinantes. Hipotetizamos que a associação entre o desenvolvimento da habilidade de voo, diminuição do provisionamento pelos pais e aumento da taxa de capturas bem-sucedidas promove a maturidade e independência no gavião-real. PALAVRAS-CHAVE: comportamento de caça, rapinantes juvenis, interações predador-presa, forrageio, Harpia harpyja CITE AS: Cavalcante, T.; Tuyama, C.A.; Mourthe, I. 2019. Insights into the development of a juvenile harpy eagle' s hunting skills. Acta Amazonica 49: 114-117.

Tropical deforestation induces thresholds of reproductive viability and habitat suitability in Earth’s largest eagles

“…Their dependent juvenile male eagle, however, quickly learned how to hunt black vultures ( Coragyps atratus ) and accounted for 9 of our 10 records of harpy predation on vultures. Hunting by recently-fledged harpy eaglets is not unheard of 55 and is especially common in fledged males 56 , 57 . We emphasise that a harpy eagle requires ~ 800 g of prey each day 58 , an unfeasible target if they are forced to rely on a mixed diet of forest birds.…”

Taphonomy of harpy eagle predation on primates and other mammals

“…Perforations in the orbits are also common in the primate crania analyzed. Both crowned eagles and harpy eagles inflict damage to the brain of their victims by perforating the cranium with their talons (Cavalcante et al, 2019; Gilbert et al, 2009; Sanders et al, 2003; de Souza Martins et al, 2005). However, crania tend to show a higher survivability in crowned eagle kill assemblages, which may be explained by the more powerful talons of harpy eagles, which inflict more pressure and consequently cause more fragmentation.…”

Harpy Eagle Harpia harpyja nest activity patterns: Potential ecotourism and conservation opportunities in the Amazon Forest

“…An extensive network of roads for logging and trails used for Brazil nut Bertholletia excelsa extraction provide relatively easy access to a number of Harpy Eagle nests (Cavalcante et al . 2019, Miranda et al 2019). These roads and trails make Harpy Eagles relatively visible in a highly accessible landscape.…”

“…With the expansion of the Arc of Deforestation-and the economy of ranching in that region -new roads and airports have made the Arc accessible from the rest of Brazil (ZSEE 2008, Carrero et al 2020). An extensive network of roads for logging and trails used for Brazil nut Bertholletia excelsa extraction provide relatively easy access to a number of Harpy Eagle nests (Cavalcante et al 2019, Miranda et al 2019. These roads and trails make Harpy Eagles relatively visible in a highly accessible landscape.…”