Foraging Patch Selection by Snail Kites in Response to Vegetation Structure and Prey Abundance and Availability

Abstract

Abstract The role of food abundance and vegetation structure in selection of foraging habitat by the Snail Kite (Rostrhamus sociabilis) was explored. Selection of available foraging patches of either dense or sparse habitat structure within two prairie habitat types used extensively by foraging kites, Eleocharis flats and Panicum flats were examined. Estimated Apple Snail (Pomacea paludosa) densities on our study site ranged from 0.33 to 1.58 per m2. Vegetation structure (sparse vs. dense) of the habitat type had a greater influence on where prey was captured than did site, the dominant emergent vegetation, or prey abundance. These results are consistent with previous suggestions that dense vegetation may obscure prey and limit or preclude use of densely vegetated habitats by foraging kites. This may be true, even when prey is in relatively high abundance, and may indicate the difference between prey abundance and availability. Most water management recommendations related to the Snail Kite call for prolo...