Foraging Ecology of the Long‐Nosed Bat, Glossophaga Soricina, With Respect to Resource Availability

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Abstract
The relationship between foraging behavior and resource availability for the long—nosed bat (Glossophaga soricina) and five species of plants it fed on in northern Columbia was investigated in a 10—mo study. Glossophaga employed two foraging tactics: (1) territorial defense of concentrated food sources, and (2) trapline foraging along regularly used feeding routes. The tactic used depended on availability of Agave desmettiana nectar and the individual bat's ability to dominate conspecifics. When both hunger and nectar levels were highest, bats concentrated their feeding activity on A. desmettiana. Aggressive behavior was displayed by dominant male and female bats during the first 3—5 h of feeding. Territorial behavior ceased suddenly when nectar levels were depleted by 50% or more at 2.5—5 h after sunset. Later in the evening, bats foraged briefly from one plant to another at several species along regularly used routes. Bats that maintained early—evening territories had increased access to nectar—rich agave flowers and had significantly smaller total foraging areas than nonterritorial bats. The feeding territories of female Glossophaga were shared with their immature offspring. Territorial behavior at agave was attributed in part to defensibility of its flowers. Foraging experiments demonstrated that G. soricina used a feeding strategy that was efficient with respect to choice of food patch and allocation of time. This is the first study that used marked individuals to document feeding territories and trapline foraging for nectar—feeding bats.