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

Summary Tourism can be a powerful tool for wildlife conservation if well controlled and responsibly managed. Apex predators constitute particularly attractive subjects for tourism, but simultaneously they may generate conflict with local communities. Harpy Eagles Harpia harpyja are the largest eagle species and are highly sought-after by ecotourists. The last stronghold of the Harpy Eagle is the Amazon Forest, which is being deforested for cattle ranching. We tested methods for developing Harpy Eagle ecotourism as a potential tool to harmonize these issues. Using camera traps, we collected data on timing of Harpy Eagle visits to their nests, as well as on probabilities of viewing an eagle. Harpy Eagles can only be seen predictably during the first 12 of the 30–36 month nest cycle. In nests with nestlings (up to 5–7 months), adults are visible on a daily basis, and this period lasts 16.6% of the nesting cycle, demanding a minimum of 13, 17, and 26 nests to have at least one nest with a nestling on 90%, 95% and 99% of the days. After this 5–7 month window, we found that two and 4.16 days spent at nests afforded high probabilities of sighting a fledgling or adult eagle, respectively. Harpy Eagles were mainly active at the beginning and the end of the day. Activity core lasted 6.5 decimal hours for adults, peaking at 10h00, and 7.45 decimal hours for fledged eagles, peaking at 15h00. Our results demonstrate that Harpy Eagles fit several criteria for a viable wildlife attraction: predictable in activity and location, viewable, and diurnal, even though at the same time they are considered a rarity. In a broader perspective, Harpy Eagle tourism shows every indication of being a significant tool for more robust rainforest conservation.

UTILIZAÇÃO DE APRENDIZADO PROFUNDO PARA CLASSIFICAÇÃO ENTRE DIFERENTES ESPÉCIES DE ACCIPITRÍDEOS

Introdução: Accipitrídeos são aves voadoras membros da família Accipitridae, cujos representantes mais simbólicos são as águias, alguns gaviões e os abutres do velho mundo. Para fins de classificação, neste trabalho escolhemos as seguintes águias: Harpia (Harpia harpyja), águia-careca (Haliaeetus leucocephalus), águia-dourada(Aquila chrysaetos) e águia-das-filipinas (Pithecophaga jefferyi). Dentre essas, a águia-das filipinas e a harpia encontram-se ameaçadas devido a destruição do seu habitat e caça ilegal. Assim, ferramentas que possibilitam classificação rápida desses animais seriam importantes para auxiliar pesquisadores e leigos na diferenciação entre os accipitrídeos viventes. Objetivo: Construir um classificador de imagens que seja capaz de diferenciar entre imagens dos vários tipos de accipitrídeos com pequeno gasto computacional. Materiais e métodos: Para realizar o trabalho foi escolhida a 47 atualização do dataset “315-birds”, disponível da plataforma Kaggle, e com base no dataset foram separadas as espécies da família accipitridae disponíveis, e foi-se utilizado a proporção de divisão já pré-determinada pelo no treino/teste/validação. Para a inteligência artificial utilizou-se do pacote Keras integrado ao api Tensor Flow,e foi definida a rede neural Mobile-Net. Para gerar o modelo, treinou-se por 80 épocas em 10 seeds diferentes (327, 261, 777, 47, 954, 728, 901, 553, 419, 934). Por fim, ao fim de cada seed foi coletado as médias das métricas estabelecidas (precisão, recall e f1-score), e se calculou média geral e desvio padrão. Resultados: A avaliação do modelo retornou os seguintes resultados: recall 92%±4,8% , precisão 92,3%±4,1% e f1-score 91,8%±5,4%. O accipeterídeo que apresentou maior relativa dificuldade de ser classificado foi a Harpia (Harpia harpyja), que apresentou métricas de precisão média de 84,6%±8,45%, que mesmo com a dificuldade relatada pode ser considerado um valor aceitável. Conclusão: Conclui-se que o modelo é capaz de atingir os objetivos esperados, e assim capaz de classificar de forma satisfatória os diferentes tipos de accipitrídeos com grande confiabilidade. Além disso, o trabalho demonstra que a computação é capaz de distinguir espécies anatomicamente similares, e que pode ser expandido para outros trabalhos envolvendo outras aves ou animais diversos.

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

Apex predators are threatened globally, and their local extinctions are often driven by failures in sustaining prey acquisition under contexts of severe prey scarcity. The harpy eagle Harpia harpyja is Earth’s largest eagle and the apex aerial predator of Amazonian forests, but no previous study has examined the impact of forest loss on their feeding ecology. We monitored 16 active harpy eagle nests embedded within landscapes that had experienced 0 to 85% of forest loss, and identified 306 captured prey items. Harpy eagles could not switch to open-habitat prey in deforested habitats, and retained a diet based on canopy vertebrates even in deforested landscapes. Feeding rates decreased with forest loss, with three fledged individuals dying of starvation in landscapes that succumbed to 50–70% deforestation. Because landscapes deforested by > 70% supported no nests, and eaglets could not be provisioned to independence within landscapes > 50% forest loss, we established a 50% forest cover threshold for the reproductive viability of harpy eagle pairs. Our scaling-up estimate indicates that 35% of the entire 428,800-km2 Amazonian ‘Arc of Deforestation’ study region cannot support breeding harpy eagle populations. Our results suggest that restoring harpy eagle population viability within highly fragmented forest landscapes critically depends on decisive forest conservation action.

Power lines as a threat to a canopy predator: electrocuted Harpy Eagle in southwestern Brazilian Amazon

Here we report an electrocution event of a juvenile Harpy Eagle Harpia harpyja in Alta Floresta D’Oeste municipality in Rondonia state, Brazil. We also discuss the negative effects that power transmission lines can have on Harpy Eagle populations in highly fragmented environments.