The feeding behavior of the cattle egrets (Bubulcus ibis L.) in northeastern arid zone of Nigeria

The cattle egrets (Bubulcus ibis L.) are historically and traditionally called the white birds of terrestrial foragers, foraging in pastures, farmlands and grasslands along side grazing livestock, capturing any disturbed insect prey. They nest in areas and territories, which are of little importance as food source, e.g., thorny Acacia sayel, A. albida and A. meliferai in Mbodewa, Jebra and Konduga sites during the rainy season (May- August), which is the period of nesting as food and water were abundant. Parents fed their young biparentally, through mouth to mouth, regurgitation of food boluses onto nest floor, from which chicks would peck and through bill grabbling and jerking pull on the parent bill, to receive food boluses obtained from foraging sites. Mean chick feeding visits were 3.9 daily, but mean feeding visits differed significantly by stage, four times for chicks, seven times for juveniles and three times for ages 30 days up-wards. Food delivery to offspring were highest from age 22 days (three weeks) to 42 days (seven weeks) in all sites and corresponded to high growth rate during the same period. The mean weight of crop content per gram weight of the body of the birds showed the content to food delivery and growth rate. Males took more time to care for chicks after hatching (75%) as against females (25%). Boluses delivery (71.3%) as against (28.7%) for females and was confirmed by the female skewed sex ratios at foraging sites, as males took greater portion of the day for attendance. Orthopterans being the most abundant insects in the and zone, topped the consumption figures per bird in all stages of the birds development (50.8%) per day and showed similar results when analyzed for its economic importance in agriculture (51.1 %) as it helps control 88.7% of insect with pest-status in the agricultural fields. Feeding success among chicks was directly correlated to age and success in fight and competit i on among siblings, because increases in body weights (g) were also directly correlated to food supply and age. Chicks left nests as juveniles at the age of 56-60 days as young adults to fend for themselves, because at this age parents found it difficult to meet their food demands. They became independent at the age of 70 days after hatching, foraging in flock, in pans or as single birds in foraging sites. Bird samples for study were obtained through hand picking and double barrel shot gun where observations were by using binoculars, video and still cameras.