6 research outputs found
Apparent survival and cost of reproduction for White-lined Tanager (<i>Tachyphonus rufus</i>, Thraupidae) in the northern Atlantic Rainforest, Brazil
<div><p>Understanding latitudinal variation in avian life-history traits has been a focus of many demographic studies around the world. However, we still know little about annual or intra-annual demographic variation within tropical regions or about how factors such as breeding season and precipitation influence demographic rates. In this study, we estimated intra-annual apparent survival of the White-lined Tanager (<i>Tachyphonus rufus</i>) using capture-mark-recapture data from northeastern Brazil. We tested whether survival varied seasonally (breeding vs. non-breeding), with rainfall, by age and residence status in our study area. Intra-annual apparent survival was correlated with the reproductive cycle, being lower during the breeding (0.65 ± 0.16 SE) vs. the non-breeding season (0.97 ± 0.05 SE). The annual apparent survival (~0.6) was relatively low for a tropical species. In both years, we observed highest abundance in spring (November, 3.1–3.7 birds/ha) and lowest abundance in autumn-winter periods (May-August, 1.1–1.4 bird/ha). The low survival during the breeding season probably reflects the trade-off between survival and reproduction and the cost of reproduction. Our findings represent an advance in the understanding of the demography of tropical birds because we did not find a predicted high annual apparent survival, and we elucidated some aspects of intra-annual variation in survival. Further exploration of latitudinal variation in demographic traits, especially in diverse, but poorly known habitats is needed to fully vet and develop life history theories.</p></div
Average annual estimates of apparent survival (Φ; mean ± SD) and the maximum and minimum values estimated for Neotropical birds.
<p>Average annual estimates of apparent survival (Φ; mean ± SD) and the maximum and minimum values estimated for Neotropical birds.</p
Estimates of intra-annual apparent survival based on Huggins robust design models for the White-lined Tanager (<i>T</i>. <i>rufus</i>) in northeastern Brazil.
<p>Estimates of intra-annual apparent survival based on Huggins robust design models for the White-lined Tanager (<i>T</i>. <i>rufus</i>) in northeastern Brazil.</p
Model-averaged estimates of capture (<i>p</i>) and recapture (<i>c</i>) based on Huggins robust design models for the White-lined Tanager (<i>T</i>. <i>rufus</i>) in northeastern Brazil.
<p>The vertical bars represent standard error estimates.</p
Top nine Huggins robust design models for a population of White-lined Tanager (<i>T</i>. <i>rufus</i>) in northeastern Brazil.
<p>These nine represent 99% of the weight in the entire model set. The global model and the constant model (23<sup>rd</sup> and 61<sup>st</sup> ranked model in the set respectively) are shown for comparison.</p
Intra-annual estimates of abundance (mean ± SE) for the White-lined Tanager (<i>T</i>. <i>rufus</i>) in a 12 ha surveyed area of northeastern Brazil based on Huggins robust design models and conditional on birds being first captured on the study site.
<p>Intra-annual estimates of abundance (mean ± SE) for the White-lined Tanager (<i>T</i>. <i>rufus</i>) in a 12 ha surveyed area of northeastern Brazil based on Huggins robust design models and conditional on birds being first captured on the study site.</p