Meeting Abstract

P1.210  Friday, Jan. 4  Neuroendocrine basis of cooperative breeding in the sociable weaver CHAN, H*; DEMATHIEU, SL; LOPES, PC; JOHNSTON, N; KRAUSE, JS; BENTLEY, GE; Univ. of California, Berkeley; Univ. of California, Berkeley; Univ. of California, Berkeley and GABBA, Univ. of Porto; Univ. of California, Berkeley; Univ. of California, Davis; Univ. of California, Berkeley and Helen Wills Neuroscience Institute hilarychan@berkeley.edu

Cooperative breeding is one of Nature’s enigmas. Why would individuals delay reproduction to help care for young that are not their own? Primarily studied from an ecological and evolutionary perspective, essentially nothing is known about the neuroendocrine control of cooperative breeding in birds. Gonadotropin-releasing hormone (GnRH) and gonadotropin-inhibiting hormone (GnIH), key neuropeptides in regulating reproductive physiology, are logical candidates for the regulation of cooperative breeding. While GnRH activates reproductive physiology and behavior, GnIH inhibits them. To explore differences in these neuropeptides associated with being a breeder or a non-breeding “helper”, we studied the sociable weaver (Philetairus socius). These birds live in large communal nests in semi-arid regions of southern Africa and breeding is linked to rainfall. From behavioral observations during the rainy season, we established the identity of individuals visiting each chamber containing offspring. We captured the birds and collected their blood and brains. The brains were processed via immunohistochemistry for the presence of GnRH and GnIH. Blood was used to examine steroid concentrations and determine paternity. By exploring a role for GnRH and GnIH in mediating the different behavioral phenotypes found in cooperative breeding species, our findings help us gain insight into the mechanisms controlling reproductive inactivity in helpers and contribute to further our understanding of the neural basis of cooperative breeding.