Nesting biology of the Small-billed Elaenia (Elaenia parvirostris) in a forest with high conservation value in east-central Argentina

Abstract

Habitat loss and fragmentation significantly affect avian breeding success. East-central Argentina’s few native forests have become increasingly degraded by humans over time. Understanding the relationship between forest health and nesting success is critical since this information will be valuable as a point of comparison with future research if management actions are not taken. The study had two objectives: 1) describe the nesting biology of the Small-billed Elaenia (Elaenia parvirostris) and 2) assess whether a set of habitat features and time-specific variables had an effect on nest survival. We monitored 99 nests during three breeding seasons (2015–2018). Of all nests, 39% were successful, with predation causing the majority of nest failures (59%). We did not find important effects of habitat features on daily nest survival rate (DNSR). There was a cubic effect of nest age on the DNSR. Estimates of the cumulative probability to survive the entire nesting cycle was 41.2% (55.5% for egg laying, 16.1% for incubation, and 52% for nestling period). Our results add to the scientific understanding of life history strategies for south temperate birds while highlighting the need for additional research on native forest disturbances.