Population structure, feeding habits and activity patterns of the African sacred ibis (Threskiornis aethiopicus) in Dilla Kera area, Southern Ethiopia

Abstract

A study on population structure, feeding habits and activity patterns of the African sacred ibis (Threskiornis aethiopicus) was carried out around Dilla Kera area during April–September, 2015. Two 3 km long transects were laid using GPS. Birds were counted within a 50 m belt on either side of the transects twice a day (06:30–10:30 h and 15:30–18:30 h) by walking along the transect lines. Focal animal sampling method was used to study activity patterns. Data were documented twice monthly for six months including dry and wet seasons. Data were analysed using descriptive statistics, independent t-test and chi-square test. Kruskal-Wallis test was performed to compare activities between time blocks. A total of 165 individuals were counted during the dry season and 53 individuals during the wet season. Counts during the dry season were significantly higher than those during the wet season (χ²=56.8 df=1, p<0.05). The average mean population density of African sacred ibis in the area was estimated to be 20.55±3.28 individuals/km². The age ratio of adult to juvenile was 1:0.46 and 1:0.56 during dry and wet seasons, respectively. Feeding on carrions, worms, insects, and other invertebrates was the most important diurnal activity of the African sacred ibis, followed by scanning, flying, preening and resting. African sacred ibis is an opportunistic feeder, which can shift to non-natural food items when the abundance of the prey is less.

Key words/phrases: Activity patterns, African sacred ibis, Dilla Kera area.