When to approach novel prey cues? Social learning strategies in frog-eating bats

Abstract

Animals can use different sources of information when making decisions. Foraging animals often have access to both self-acquired and socially acquired information about prey. The fringe-lipped bat, Trachops cirrhosus, hunts frogs by approaching the calls that frogs produce to attract mates. We examined how the reliability of self-acquired prey cues affects social learning of novel prey cues. We trained bats to associate an artificial acoustic cue (mobile phone ringtone) with food rewards. Bats were assigned to treatments in which the trained cue was either an unreliable indicator of reward (rewarded 50% of the presentations) or a reliable indicator (rewarded 100% of the presentations), and they were exposed to a conspecific tutor foraging on a reliable (rewarded 100%) novel cue or to the novel cue with no tutor. Bats whose trained cue was unreliable and who had a tutor were significantly more likely to preferentially approach the novel cue when compared with bats whose trained cue was reliable, and to bats that had no tutor. Reliability of self-acquired prey cues therefore affects social learning of novel prey cues by frog-eating bats. Examining when animals use social information to learn about novel prey is key to understanding the social transmission of foraging innovations.

Not-so-social learning strategies

“…Thus, being trained in the presence of a bat that reliably went to B encouraged the observers in group 50-social to reverse their original preference for A over B. According to Jones et al [8], this reversal was a consequence of group 50-social adopting the strategy of copy when dissatisfied, where the dissatisfaction arose from the introduction of the 50% schedule associated with A. Support for this interpretation is provided by the additional finding that during the test, group 100-social, which presumably did not experience dissatisfaction, did not relinquish its original preference for A.…”

Male‐biased dispersal and the potential impact of human‐induced habitat modifications on the Neotropical batTrachops cirrhosus

“…As cooperation both between related and unrelated females is frequently observed in this species (Carter & Wilkinson, ), (kin)cooperation seems to be the driving force for the observed female philopatry and male‐biased dispersal. While T. cirrhosus can quickly acquire novel foraging behavior by observing conspecifics (Jones, Ryan, Flores, & Page, ; Page & Ryan, ), the social learning observed in this species is via eavesdropping where one individual opportunistically observes the foraging behavior of another. Thus, unlike Desmodus rotundus , female T. cirrhosus are likely not cooperating while foraging or in sharing food resources at the roost.…”

Perceptual bias does not explain preference for prey call adornment in the frog-eating bat

“…It is likely both mechanisms contribute to this preference, although we believe that learning might play a greater role than innate preferences as both T. cirrhosus and other bat species have been shown to be highly plastic and quick to learn in their foraging decisions and response to prey cues (Siemers 2001;Page and Ryan 2005;Ratcliffe and ter Hofstede 2005;Jones et al 2013b;O'Mara et al 2014). For example, a reversal learning experiment with T. cirrhosus demonstrated that after only five rewarded trials bats can develop positive phonotaxis toward the call of a poisonous toad species to which they were initially strongly averse (Page and Ryan 2005), and bats can socially learn to associate completely synthetic calls (phone ringtones) as prey calls (Jones et al 2013b). This novel response could then be transmitted rapidly between bats via social learning, suggesting that once an innovative response to prey cue arises, it can spread rapidly in a population (Page and Ryan 2006;Jones et al 2013b).…”

“…For example, a reversal learning experiment with T. cirrhosus demonstrated that after only five rewarded trials bats can develop positive phonotaxis toward the call of a poisonous toad species to which they were initially strongly averse (Page and Ryan 2005), and bats can socially learn to associate completely synthetic calls (phone ringtones) as prey calls (Jones et al 2013b). This novel response could then be transmitted rapidly between bats via social learning, suggesting that once an innovative response to prey cue arises, it can spread rapidly in a population (Page and Ryan 2006;Jones et al 2013b). An interesting experiment that would serve to elucidate the role of learning in this eavesdropper preference would be to compare the strength of this preference between juvenile bats and adult bats at sites where T. cirrhosus shows a preference for complex calls over simple calls.…”