Contributions to Fledgling Feeding in the Florida Scrub Jay

• Published in: The Journal of animal ecology 1990-06, Vol.59 (2), p.691-707
• Main Authors: McGowan, Kevin J., Woolfenden, Glen E.
• Format: Article
• Language: English
• Subjects: Animal ethology; Aves; Aviculture; Biological and medical sciences; Bird nesting; Boluses; Breeding; Female animals; Food; Food security; Fundamental and applied biological sciences. Psychology; Male animals; Psychology. Psychoanalysis. Psychiatry; Sparrows; Vertebrata; Yearlings
• ISSN: 0021-8790; 1365-2656
• DOI: 10.2307/4889

(1) The provisioning of fledgling Florida scrub jays was studied at the Archbold Biological Station, Florida for two breeding seasons. The amount of food provided by breeding and helper jays was quantified, and effects of helper contributions were examined. (2) Feeding of Florida scrub jay fledglings by adult jays extended from fledging at about 18 days of age to nutritional independence at about 85 days of age. Fledglings were fed for a longer period of time and at a greater rate than were nestlings, indicating greater investment by all group members in this portion of the breeding cycle. (3) Retention of young within the group may be responsible for the extended parental care seen in this population, which may be typical of cooperative-breeding bird species. (4) In contrast to results for feeding nestlings reported in a previous study, no differences were found in contributions by the various status classes of adult jays. Furthermore, all Florida scrub jay group members fed all fledglings in their group; no brood division was found. (5) Food received by each fledgling increased with increasing numbers of helpers. Neither male breeders nor female breeders decreased contributions when helpers were present. (6) Helper enhancement of survival of fledglings and breeders may be related to predator detection and not to extra food provided.