Nest Architecture, Clutch Size, Nestling Growth Patterns and Nestling Attendance of the Fire-eyed Diucon (Xolmis pyrope) in North-Central Chile

Abstract

We present descriptions of nest architecture, clutch size, nestling growth and nestling attendance for the Fire-eyed Diucon (Xolmis pyrope), based on nests found at the Fray Jorge National Park, Chile, at the northernmost part of its distribution. Nests were cup-shaped structures averaging 283.5 +/- 26.6 mm in width and 123.1 +/- 6.8 mm in height (n = 5), found in matorral steppe habitat and Olivillo humid forest relicts. Nests contained 2-3 eggs. Nestling growth in Fray Jorge's nests was nearly two times slower than in populations from central Chile, as suggested by our calculations of the constant rate (K = 0.277) and the T10-90 period (12.9). During 20 hrs of video recording, the breeding adults spent a total of 3.4 hrs at the nest. Both parents attended the nest, and the rates of visits, nestling provisioning and fecal sac removal increased with nestling development. We observed that adults can still care for the young at least 2 weeks after fledging, covering an area of 2.3 ha while searching for food. This information could be valuable for further studies on geographic variation in the species' behavioral ecology.