A1 Refereed original research article in a scientific journal
Kalahari skinks eavesdrop on sociable weavers to manage predation by pygmy falcons and expand their realized niche
Authors: Lowney Anthony M, Flower Tom P, Thomson Robert L
Publisher: OXFORD UNIV PRESS INC
Publication year: 2020
Journal: Behavioral Ecology
Journal name in source: BEHAVIORAL ECOLOGY
Journal acronym: BEHAV ECOL
Volume: 31
Issue: 5
First page : 1094
Last page: 1102
Number of pages: 9
ISSN: 1045-2249
eISSN: 1465-7279
DOI: https://doi.org/10.1093/beheco/araa057
Abstract
Eavesdropping on community members has immediate and clear benefits. However, little is known regarding its importance for the organization of cross-taxa community structure. Furthermore, the possibility that eavesdropping could allow species to coexist with a predator and access risky foraging habitat, thereby expanding their realized niche, has been little considered. Kalahari tree skinks (Trachylepis spilogaster) associate with sociable weaver (Philetairus socius) colonies as do African pygmy falcons (Polihierax semitorquatus), a predator of skinks and weavers. We undertook observational and experimental tests to determine if skinks eavesdrop on sociable weavers to mitigate any increase in predation threat that associating with weaver colonies may bring. Observations reveal that skinks use information from weavers to determine when predators are nearby; skinks were more active, more likely to forage in riskier habitats, and initiated flight from predators earlier in the presence of weavers compared with when weavers were absent. Playback of weaver alarm calls caused skinks to increase vigilance and flee, confirming that skinks eavesdrop on weavers. Furthermore, skinks at sociable weaver colonies were more likely to flee than skinks at noncolony trees, suggesting that learning is mechanistically important for eavesdropping behavior. Overall, it appears that eavesdropping allows skinks at colony trees to gain an early warning signal of potential predators, expand their realized niche, and join communities, whose predators may otherwise exclude them.
Eavesdropping on community members has immediate and clear benefits. However, little is known regarding its importance for the organization of cross-taxa community structure. Furthermore, the possibility that eavesdropping could allow species to coexist with a predator and access risky foraging habitat, thereby expanding their realized niche, has been little considered. Kalahari tree skinks (Trachylepis spilogaster) associate with sociable weaver (Philetairus socius) colonies as do African pygmy falcons (Polihierax semitorquatus), a predator of skinks and weavers. We undertook observational and experimental tests to determine if skinks eavesdrop on sociable weavers to mitigate any increase in predation threat that associating with weaver colonies may bring. Observations reveal that skinks use information from weavers to determine when predators are nearby; skinks were more active, more likely to forage in riskier habitats, and initiated flight from predators earlier in the presence of weavers compared with when weavers were absent. Playback of weaver alarm calls caused skinks to increase vigilance and flee, confirming that skinks eavesdrop on weavers. Furthermore, skinks at sociable weaver colonies were more likely to flee than skinks at noncolony trees, suggesting that learning is mechanistically important for eavesdropping behavior. Overall, it appears that eavesdropping allows skinks at colony trees to gain an early warning signal of potential predators, expand their realized niche, and join communities, whose predators may otherwise exclude them.