Document: KRI-3-50-3

Hummingbird foraging behavior in different patch types: Simulation of alternative foraging strategies.

BAUM, K.A.* and W.E.GRANT

Texas A&M University, College Station, TX 77843 USA ¹

Abstract:
We describe the development of a model simulating alternative hummingbird foraging strategies and compare predictions of each version of the model with foraging data from the field. We tested the hypotheses that: 1) natural foraging patterns more closely resembled systematic foraging than random foraging; and 2) systematic foragers were more efficient when resource distributions were clumped versus random. Simulated foraging strategies included random searching, area-restricted searching, and directional searching. During field trials and simulations, hummingbirds foraged in patches with uniform (saturated), clumped, and random nectar distributions. We measured foraging efficiency as microliters of nectar consumed per time step, assuming higher rates of consumption were more efficient than lower rates of consumption. In random patches, the hummingbirds in the field foraged the most efficiently, while the field data and area-restricted searching methods proved the most efficient in clumped patches. The random searching strategy proved more efficient in patches with random versus clumped nectar distributions, while the area-restricted searching strategy was more efficient in clumped patches. No difference existed between patch types for the directional search strategy or the field data. In the uniform patch, the directional strategy performed the most efficiently, followed by the random and field foraging strategies. The area-restricted searching strategy resulted in the least efficient foraging. This study suggests hummingbirds use different foraging strategies in different patch types and use information not incorporated into the simulated foraging rules.

Keywords: simulation, foraging behavior, hummingbird

This abstract is being presented at: 9:30 AM in session:
Oral Session #3: Avian Ecology.