Meeting Abstract

P1.4  Sunday, Jan. 4  Breeding behavior in Prothonotary Warblers: Is food availability the key? MOORE, JR*; WALTERS, JR; MOORE, IT; Virginia Tech s2jrmoor@vt.edu

Global climate change has resulted in the advancement of many phenological events in the spring such as budburst, insect emergence, and reproductive behavior of many birds. A long-term study of the Prothonotary Warbler (Protonotaria citrea) reveals that, over the past twenty years, males have advanced their arrival date by approximately three weeks however clutch initiation dates have remained unchanged. This appears to have resulted in a mismatch between timing of breeding and peaks in food availability. We examined whether experimentally supplementing food upon arrival would advance breeding and associated behaviors at two different sites in the James River Virginia watershed. Experimental pairs were supplemented with waxworms upon arrival and nest boxes were visited 3-4 times a week to determine clutch initiation dates. In addition we measured male aggression and testosterone levels in response to the food supplementation. Clutch initiation dates and male plasma testosterone levels did not differ between experimentally supplemented and control pairs. Thus it appears that while birds are arriving earlier a lack of available food is not the cue preventing them from advancing breeding.