Food selection and feeding patterns in nectarivorous bats: Leptonycteris yerbabuenae and Glossophaga soricina

TL;DR

Two nectar-feeding bat species, Leptonycteris yerbabuenae and Glossophaga soricina, show distinct feeding preferences and timing in controlled experiments, reducing competition.

Contribution

The study reveals novel insights into how sympatric nectarivorous bats avoid competition through differential resource selection and feeding patterns.

Findings

Glossophaga soricina prefers nectar similar to Ipomoea and sucrose, while Leptonycteris yerbabuenae prefers nectar similar to Acanthocereus cacti.

The two bat species exhibit different timing patterns in feeding, further reducing potential competition.

Low competition is observed under abundant resources and low individual density, but this may change with scarcity.

Abstract

Sympatric species reduce competition for resources due to differences in one or more of their niche dimensions. Biotic interactions between pollinators and variations in the availability and quality of resources are important factors that determine food selection in bats. The nectarivorous species Leptonycteris yerbabuenae and Glossophaga soricina coexist temporarily in much of their distribution and depend on nectar to feed. These species have similar requirements but differ in the way they obtain food. The coexistence of bat species with similar requirements, such as L. yerbabuenae and G. soricina, suggests that these species have strategies for avoiding competition and maximizing their nectar consumption. However, it is unclear how these bat species select resources and adjust their visits to the available floral resources. We therefore analyzed nectar selection and feeding patterns in these two bat species under captive conditions. We conducted experiments in which we controlled resource type and its availability by offering the bats different artificial nectar solutions, while we removed interspecific interactions. These solutions differed in concentration and sugar type, and some were similar to the nectar offered by chiropterophilic plant species. The bat species presented differences in food selection; G. soricina fed mainly on resources similar to Ipomoea and sucrose sugar. In contrast, L. yerbabuenae preferred those resources similar to the nectar of Acanthocereus cacti. In addition, the timing of feeding for each solution also differed. These results suggest low levels of competition between species under abundant resources and low density of individuals; however, such conditions are not always found in nature, and patterns may change with increased food scarcity and a high density of competitors.

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