Nestling development of the tropical screech-owl ( Megascops choliba ): a successful case report from the southwestern Amazon

Abstract

This study reports a successful reproductive event in Megascops choliba in eastern Acre, northern Brazil. An active M. choliba nest was monitored from the hatching of the eggs to the departure of the nestlings. Once hatched, the nestlings were weighed every two days to verify their weight gain over time. The nestlings remained in the nest for 30 days. The pattern of weight gain was similar to that found in other birds, presenting a rapid increase over the first 15 days, followed by a drastic reduction in the mean growth rate during the second half of the development period. Our observations indicate that the breeding season of M. choliba in southwestern Amazonia is similar as that reported for the species in the northern hemisphere. These are the first data on this species from this region, and contribute to the understanding of its reproductive biology within its geographic range. KEYWORDS: birds, Strigidae, growth rate, nest, state of Acre, Brazil Desenvolvimento do ninhego em corujinha-do-mato (Megascops choliba): um relato de caso bem sucedido na Amazônia sul-ocidental RESUMOEste estudo refere-se a um caso bem sucedido de reprodução de Megascops choliba no leste do estado do Acre. Um ninho ativo de M. choliba foi acompanhado desde a eclosão até o abandono dos filhotes. A partir da eclosão, os filhotes foram pesados a cada dois dias. O tempo de permanência dos filhotes no ninho foi de 30 dias. O ganho de peso dos filhotes seguiu o padrão encontrado em outros estudos com aves, ou seja, um rápido aumento de peso nos primeiros 15 dias e uma redução drástica da taxa média de crescimento na segunda metade do período de desenvolvimento. Nossas observações indicam que o período reprodutivo de M. choliba no sudoeste amazônico deve ser o mesmo relatado para a espécie no hemisfério norte. Os dados apresentados aqui são inéditos para a região e contribuem para o entendimento da biologia reprodutiva desta espécie ao longo de sua distribuição geográfica.

Glucocorticoid metabolites in an ex situ nocturnal bird, the tropical screech owl Megascops choliba: effects of sex, activity period and inter-individual variation

“…rodents Harris et al, 2013 ; owls Béziers et al, 2020 ), MGC is expected to be similar. M. choliba males have not been seen participating in egg incubation ( Lima and Lima Neto, 2009 ; Guilherme and de Souza, 2017 ). Similarly, for the spectacled owl Pulsatrix perspicillata and the barn owl Tyto alba , bi-parental care is defined as females rearing the chicks, while the male brings food for them ( Chaparro-Herrera et al ., 2017 ; Béziers et al, 2020 ).…”

“…Birds had a mean weight of 118.3 ± 9.1 g, and experiments were carried out in adult individuals from non-reproductive and non-molting phases. The reproduction of Megascops choliba is seasonal ( Guilherme and de Souza, 2017 ), which is being determined for the region of São Paulo (unpublished data). Animals were thoroughly examined one month prior to testing, including serological laboratory tests and elimination of parasites.…”

DESCRIPCIÓN DE NIDO DE LA LECHUZA CANELA Megascops petersoni (STRIGIDAE) EN AMAZONAS, PERÚ

“…pers., 2020). La ubicación de estos nidos en cavidades naturales de árboles coincide con otras especies de Megascops (Freile et al, 2003;Enríquez & Cheng, 2008;Reyes & Astudillo-Sánchez, 2017), mientras que algunas especies también pueden anidar en cavidades abandonadas por pájaros carpinteros o troncos rotos (Dias & Lima, 2015;Guilherme & Souza, 2017). Las cavidades proveen un microclima estable para los huevos (Rockweit et al, 2012).…”