Food Availability and Foraging Patterns of the Endemic Kulal White-eye (Zosterops kulalensis) in the Mount KULAL Biosphere Reserve, Northern Kenya
Jeremy Ledaany *
Kenyatta University, Nairobi, Kenya.
Joseph Ndolo
Kenyatta University, Nairobi, Kenya.
Cecilia M. Gichuki
Kenyatta University, Nairobi, Kenya.
Ezekiel Ndunda
Kenyatta University, Nairobi, Kenya.
*Author to whom correspondence should be addressed.
Abstract
The Kulal White-eye (Zosterops kulalensis) is an endemic and range-restricted bird occurring on Mount Kulal in northern Kenya. Its restricted distribution makes the species particularly dependent on the availability and quality of food resources within the Mount Kulal Biosphere Reserve. This study assessed the influence of food availability on the foraging patterns of the Kulal White-eye, focusing on fruits, nectar and insects, diet composition, foraging substrates, seasonal variation and foraging success. Data were collected from 25 sampling sites through systematic ecological observations and assessment of food-resource conditions. Moderate fruit availability was recorded at 44.0% of sites, moderate nectar availability at 48.0%, and moderate insect abundance at 40.0%. Food resources were most available during the wet season at 56.0% of sites, whereas only 20.0% of sites had resources available throughout the year. The tree canopy was the dominant foraging substrate (48.0%), while insects constituted the most frequently recorded food item (40.0%), followed by fruits (28.0%) and nectar (24.0%). Small flocks represented 48.0% of observations, while early morning was the dominant feeding period (56.0%). High foraging activity occurred at 52.0% of sites during the wet season compared with 20.0% during the dry season. A paired-samples t-test showed a significant seasonal difference in foraging activity (t = 3.74, p = 0.001), while Pearson's correlation revealed a strong positive relationship between food availability and foraging activity (r = 0.76, p < 0.001). A chi-square test also indicated a significant association between season and food availability (χ² = 12.81, p = 0.002), while one-way ANOVA showed significant differences in foraging success among the assessed season-habitat categories (F (2,22) = 7.13, p = 0.004). The findings demonstrated that food availability and seasonality strongly influenced the foraging ecology of the Kulal White-eye, highlighting the importance of conserving indigenous forest, adjoining bushland and food-producing vegetation.
Keywords: Kulal White-eye, Zosterops kulalensis, food availability, foraging ecology, seasonal variation, food resources, insect abundance, foraging success, Mount Kulal Biosphere Reserve, endemic bird conservation