Sequential assessment of prey through the use of multiple sensory cues by an eavesdropping bat

Abstract

Predators are often confronted with a broad diversity of potential prey. They rely on cues associated with prey quality and palatability to optimize their hunting success and to avoid consuming toxic prey. Here, we investigate a predator's ability to assess prey cues during capture, handling, and consumption when confronted with conflicting information about prey quality. We used advertisement calls of a preferred prey item (the túngara frog) to attract fringe-lipped bats, Trachops cirrhosus, then offered palatable, poisonous, and chemically manipulated anurans as prey. Advertisement calls elicited an attack response, but as bats approached, they used additional sensory cues in a sequential manner to update their information about prey size and palatability. While both palatable and poisonous small anurans were readily captured, large poisonous toads were approached but not contacted suggesting the use of echolocation for assessment of prey size at close range. Once prey was captured, bats used chemical cues to make final, post-capture decisions about whether to consume the prey. Bats dropped small, poisonous toads as well as palatable frogs coated in toad toxins either immediately or shortly after capture. Our study suggests that echolocation and chemical cues obtained at close range supplement information obtained from acoustic cues at long range. Updating information about prey quality minimizes the occurrence of costly errors and may be advantageous in tracking temporal and spatial fluctuations of prey and exploiting novel food sources. These findings emphasize the sequential, complex nature of prey assessment that may allow exploratory and flexible hunting behaviors.

Questions, ideas and tools: lessons from bat echolocation

“…Willis & Brigham 2007). Bats learn by watching other bats (Gaudet & Fenton 1984), behaviour that involves integrating multiple sensory cues, including echolocation (Page et al 2012) associated with social living.…”

Breaking the cipher: ant eavesdropping on the variational trail pheromone of its termite prey

“…Thus, we cannot exclude the possibility that alarm pheromones originating from defence secretions in much higher concentrations may also serve as less effective kairomones. Eavesdropping predators have been shown to accurately discriminate between vocal and vibrational signals in prey [12][13][14] and tend to select signals that may be easily distinguished, rather than necessarily conspicuous, such as signals that are evolutionarily selected for competition among and between species [2]. While trail pheromones are less abundant, they provide a reliable signal informing the predator of the presence or absence of prey.…”

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

“…A combination of perceptual bias and optimal eavesdropping is likely to contribute to all eavesdropper preferences, but the relative importance of these two mechanisms likely varies considerably across taxa. An interesting direction for future work would be to quantify the relative importance of perceptual biases in foraging decisions across animal taxa with different life history strategies and ecological characteristics, as has been done for other behavioral and cognitive traits (e.g., Careau et al 2009;Page et al 2012a). Differences in prey detection mechanisms and strategies could mimic the variance observed across animal taxa for behavioral flexibility in general (Sih et al 2004).…”