![]() In Kenya, African Pygmy-falcon nest in White-headed Buffalo-weaver nests, and the ranges of the two birds coincide. This range is estimated to have an area of 2.7 million km2, and the total population is estimated to be between 100,000 and 1 million birds. semitorquatus occurs from Angola to northern South Africa. castanonotus occurs from Sudan to Somalia and south to Uganda and Tanzania. The African Pygmy-falcon inhabits dry bush. The call is “a high-pitched kikiKIK, repeated” (Kenya) or “a ‘chip-chip’ and a ‘kik-kik-kik-kik’” (southern Africa). In size, pattern, and the habit of perching upright on an exposed branch or treetop, this species resembles some shrikes. The flight feathers of the wings are spotted black and white (more black above, more white below) the tail is barred black and white. Juveniles have a brown back, duller than adult females, and a rufous wash on the breast. There are white “eye spots” on the (back of a bird’s neck). With this work, we expand the number of studies on raptor cooperative breeding and explore the fitness advantages of group breeding in this species as well as the mechanisms behind group formation.Adult African Pygmy-falcons are white below and on the face, grey above, the female having a chestnut back. We also found that groups produced healthier fledglings than pairs and that groups are more likely to occur following years with high fledgling success. Helpers were also either adult immigrants or retained offspring. These breeding groups included the breeding pair plus helpers that are either males or females. We studied the breeding performance and social organisation of the African pygmy falcon and found that they form breeding groups at 19% of the nests. It occurs in approximately 9% of bird species and it is particularly frequent in diurnal raptors. SIGNIFICANCE STATEMENT: Cooperative breeding occurs when more than two individuals contribute to raising a brood of young. Pygmy falcon group composition proved to be highly variable and diverse compared to other raptor species, in which helpers are generally unrelated adult males, showing that selection pressures leading to group formation in diurnal raptors may be more diverse than previously thought. Breeding groups were also described as multi-male (65%), multi-female (26%) and multi-male-female (9%). We identified groups that included retained offspring (46%), immigrant adults (27%) or both types of helpers (27%). Indeed, most of the helpers (77%) were non-dispersed offspring from the previous year, whereas the other helpers were immigrant adults (23%). Cooperative breeding groups were more likely to occur following years of higher reproductive output. Helper presence had a positive effect on the body condition of the chicks as brood size increased, likely due to their contribution to feeding the chicks. Using data from six breeding seasons, we found helpers at 19% of nests. Here, we present a detailed study of the reproductive output and social organisation of the African pygmy falcon. Many diurnal raptors exhibit cooperative breeding, although occurrence rates are mostly based on anecdotal observations at nests. This breeding strategy is strongly linked to phylogeny therefore, studies on species within groups where cooperative breeding is more prevalent could improve our understanding. 16 ISSN: 0340-5443 Subject: adults, alloparental behavior, birds of prey, body condition, breeding, breeding season, chicks, falcons, females, fledglings, immigration, males, nests, phylogeny, prediction, progeny, reproductive performance, social structure Abstract: Universal predictions on the occurrence of cooperative breeding are still elusive. ![]() ![]() Thomson Source: Behavioral ecology and sociobiology 2019 v.73 no.2 pp. Helpers improve fledgling body condition in bigger broods of cooperatively breeding African pygmy falcon Author: Diana Bolopo, Anthony M. ![]()
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |