Influence of changing rainfall, parental traits, and nest traits on parental care in a tropical bird, The
presentationposted on 19.06.2017, 00:00 by Sarah Brannon
The extent of parental care may be highly variable within individuals and across years. In the tropics, parents provide extensive care and this strongly impacts juvenile survival, a period that strongly impacts population growth. We asked the following research question: How do traits of the parents (age, sex), traits of the nest (age of young, time of year), and climate (rainfall, temperature) affect parental care? We examined parental care in a well-studied tropical bird species, Thamnophilus atrinucha, in Panama during two extreme years (El Niño/La Niña years). Nests were videotaped during incubation and nestling stages to determine nest attentiveness, provisioning rates, and food load. Nest attentiveness, total food brought to the nest, and prey loads were lower in the wetter La Niña year compared to the drier El Niño year, while provisioning rates and on- and off-bouts did not change. Females reduced nest attentiveness with older eggs and altered incubation on- and off-bouts in response to time of year and monthly rainfall, while male behaviors did not change. Older nestlings received more food than younger nestlings. Although rainfall over the breeding season decreased parental care, in months with higher rainfall, females had higher prey loads. Our results suggest that changing rainfall (predicted with climate change), traits of parents, and age of young may alter parental care, and subsequently may alter juvenile survival and recruitment.