Nesting biology of the Red-crested Cardinal (Paroaria Coronata) in south temperate forests of central Argentina

Abstract

Studies on breeding biology in Neotropical birds are crucial for understanding different aspects of their life histories and also for their conservation. We describe the nesting biology of the Red-crested Cardinal (Paroaria coronata) in central Argentina, a common suboscine that inhabits south temperate forests. We monitored 367 nests from October to February 2005-2008. Nest initiation followed a unimodal distribution with a peak in November. Within the forest, no nests were built on exotic tree species. Mean clutch size was 3.05 ± 0.05 eggs and decreased with time within the breeding season; egg size did not vary across the breeding season. Nesting cycles lasted, on average, 25.8 ± 0.1 days (nest construction: 6.1 ± 0.4 days; incubation period: 11.9 ± 0.1 days; nestling period: 13.8 ± 0.1 days). At least one young fledged in 26% of nests, 62% were depredated, and 11% were abandoned. Egg survival rate was 0.95 ± 0.02, hatching success rate was 0.84 ± 0.02, and nestling survival rate was 0.81 ± 0.03. Partial nestling losses were detected in 45% of the nests, of which 52% were because of brood reduction. Each breeding pair had on average 4.4 ± 0.2 nesting attempts over the breeding season. Our results support the prediction that small clutch sizes are associated with extensive breeding seasons and several nesting attempts within a season. Except for the short incubation period, all other breeding features reported in this study differ from those of most north temperate birds and are consistent with the life history traits of Neotropical birds.