A contribution to the ecology and reproductive biology of the Marabou stork (Leptoptilos crumeniferus) in East Africa

Abstract

Marabous are common scavengers in regions where game or domestic animals are abundant or near human settlements. Adults are able to subsist for long periods on a diet of carrion, but the rapidly growing nestlings require a high‐calcium diet containing some small whole vertebrates, such as fish or frogs. Most breeding colonies are situated near a source of carrion as well as a freshwater feeding area. Breeding generally takes place in the dry season, when aquatic vertebrates are concentrated and carrion is easier to obtain. Observations are presented on the various phases of the breeding cycle. The incubation period averaged 30–3 days, and the young stayed in the nest an average of 116 days before their first flight. Parents commonly bring water, as well as food, to young in the nests. Only a small percentage of the population appears to breed in any given year, and the rate of productivity is low; some birds must live to be very old. Population size is probably controlled by food availability and its influence on reproductive success.

Influence of rainfall on timing and success of reproduction in Marabou Storks Leptoptilos crumeniferus

“…Before these possibilities can be assessed, further information on the diet of Marabou Storks is required. Marabous may utilize different food sources during breeding and non‐breeding seasons, as chicks require high levels of calcium in their diet (Kahl 1966a).…”

“…Among White Storks breeding in temperate Europe, rainfall during the nesting season has a negative effect on chick survival (Tortosa & Castro 2003, Jovani & Tella 2004), due to the inability of chicks to thermoregulate. Nest predation does not seem to be a major cause of nest failure in either Marabous or White Storks (Kahl 1966a, Vergara et al. 2006).…”

Ontogeny of chick behavior: a tool for monitoring the growth and development of lesser adjutant storks

“…In the wild, breeding usually correlates with food availability [Kahl, 1966;Pomeroy, 1978;Hancock et al, 1992;Hoyo et al, 1992;Bhattacharjee and Saikia, 1996;Singha et al, 2003]. From 1996 to 2003, the storks were housed together outside, but only formed pairs and bred indoors.…”

“…These hypotheses about timing of behavioral development were tested on two chicks that hatched outdoors at the Bronx Zoo in May and June 2006, and the data correctly predicted the sex of both individuals [Bronx Zoo, Department of Ornithology, 2006]. Similar to the male chick from 1999, Kahl [1966] reported nutritional problems when raising marabou chicks in captivity. In his study, some chicks were lost because of fragile and brittle bones, whereas others survived when offered food with more calcium, but showed a retarded rate of behavioral development.…”

“…We developed an ethogram using information in the literature, previous observations from the Bronx Zoo, and the current data [Kahl, 1966[Kahl, , 1971[Kahl, , 1972aHancock et al, 1992;Hoyo et al, 1992;Bhattacharjee and Saikia, 1996;Arland et al, 2003;Maust, 2003a,b;Singha et al, 2003;Bronx Zoo, Department of Ornithology, 2006].…”