Using molt patterns to age Russet-crowned Warbler (Myiothlypis coronata)

作者：Chumpitaz-Trujillo Kevin M.; Newell Felicity L.^*; Ausprey Ian J.

来源：Ornitologia Neotropical, 2018, 29: S75-S81.

• Ageing
• Cloud forest
• Molt limits
• Parulidae
• Peru

Understanding the age and sex distributions of Neotropical birds is key to describing population dynamics and demographics to inform conservation. Despite the utility of molt patterns, reproductive characteristics, and morphometrics for determining the age and sex of individuals, few published descriptions exist for Neotropical birds. In this study, we use molt, breeding characteristics, and morphometrics to develop reliable ageing and sexing criteria for the Russet-crowned Warbler (Myiothlypis coronata), a common species found throughout the Andes. From June to November 2015 and 2016, we captured 456 individuals of Myiothlypis coronata in the cloud forest of northern Peru, and recorded molt limits in 122. As in other warblers, Myiothlypis coronata has a partial preformative molt, and normally 6 to 9 inner greater coverts are replaced. A molt limit in the outer greater coverts was obvious in most individuals. The prebasic molt was complete and we did not observe individuals undergoing a prealternate molt. Skull ossification was typically complete, and serves as an additional tool to age birds. We found evidence for sexual size dimorphism, and wing length of 56 males measured >= 68 mm compared to <= 68 mm for 12 females. This study provides useful methods to determine population age structure for a common species along the length of the Andes.

• 出版日期2018