Breeding biology of Sri Lanka White-eye Zosterops ceylonensis (Aves: Passeriformes: Zosteropidae) in tropical montane cloud forests, Sri Lanka

Abstract

Breeding biology of the endemic Sri Lanka White-eye Zosterops ceylonensis was studied from January 2017 to January 2018 in the montane cloud forests of Horton Plains National Park, in Nuwara Eliya District of Sri Lanka. A total of 46 active nests were studied. Breeding occurred March–May. The peak egg-laying was in March and April. Mean nest construction period 11±2.87 days (n= 17), nest height was 3.16±1.22 m from the ground. Majority of nests were built on Sarcococca brevifolia, Berberis ceylanica, and Cinnamomum ovalifolium trees of 4–12 m tall. Most number of pen cup nests were constructed by the fine grass stalks and mosses woven with cobwebs and internal cup lined with grass roots. Eggs were pale blue. Mean clutch size 2.15±0.37 eggs (n= 11). The incubation period was 10.92±0.9 days (n= 11). Nestling period was 28.33±1.55 days (n= 11). Both sexes participate in nest construction, incubation and brood rearing. About 25.53% of nests were depredated (N= 12). The overall nest success was 74.46%. The study reveals that undisturbed cloud forests are critical to conservation of Sri Lanka White-eye.