Habitat use and foraging ecology of Hudsonian Godwits Limosa haemastica in southern South America
105 – 108
1 August 11
Nathan R. Senner, Kate S. Coddington
Nathan R. Senner
Cornell Laboratory of Ornithology, Cornell University, New York, USA.
Hudsonian Godwits Limosa haemastica are widely distributed across the southern cone of South America during the austral spring, summer and fall (Sep–Apr). Despite their relative abundance, little effort has been made to quantify godwit habitat use and foraging ecology during their stay in the Southern Hemisphere. During an eight-month tour of godwit migration stopover sites and areas of concentration outside the breeding season in Peru, Brazil, Uruguay, Argentina and Chile, we sought a better understanding of the types of habitats godwits frequent and their numbers and foraging patterns. During this tour, we opportunistically collected data on the foraging ecology of godwits at 15 sites. Across all sites, godwits averaged 58.36 probes/minute and 1.82 prey items/minute. Using one-way ANOVAs, we found that godwit foraging behavior differed across all sites, but varied little between sites. Only Rio Grande, Argentina and Bahía Lomas, Chile significantly differed in the number of probes/minute. Across habitat types, those sites characterized by the softest sediments had higher numbers of probes and prey items captured per minute than did sandy or inland sites, and it may be that this difference, and the resulting differences in prey type and abundance, is what dictates the observed inter-site variation in these rates. This is the first study to quantitatively assess godwit foraging ecology at a large geographical scale and, along with our anecdotal observations of godwit habitat usage, should prove useful in future assessments of habitat quality and godwit behavior.