| Publication Type: | Journal Article |
| Year of Publication: | 1986 |
| Authors: | Gayou, DC |
| Journal: | The Auk |
| Volume: | 103 |
| Issue: | 3 |
| Date Published: | 1986 |
| ISBN Number: | 00048038 |
| Keywords: | Corvidae, Cyanocorax, Cyanocorax luxuosus, Cyanocorax yncas, Garrulus, Garrulus glandarius |
| Abstract: | Accessory birds were absent at the nests of Green Jays (Cyanocorax yncas). However, young stayed in the family flock for one year. After the young from the following year fledged, the 1-yr-old young were forced from their natal territory by the breeding male. These young either dispersed into adjacent habitat or became floaters within their former territories until, possibly, a breeding position opened up in a family flock. The yearlings provided a significant amount of territorial defense, which freed the breeders of much of the energetic costs inflicted on them by the stringent territoriality required in south Texas habitat. I propose that south Texas Green Jays represent an early stage in the evolutionary sequence of development of cooperative breeding as a response to environmental factors. The retention of young on the natal territory without helping at the nest represents an evolutionary early step, heretofore only hypothesized, that may lead to a more complex cooperative system that includes helpers at the nest. |
| URL: | http://www.jstor.org/stable/4087126 |
| Short Title: | The Auk |
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