Implications of sensory ecology for species coexistence: biased perception links predator diversity to prey size distribution

Abstract

Inherent to sensory systems is a discrepancy between the perceived and the actual environment. We modelled prey perception in different species of echolocating bats and show that differences in sensory systems can be important for shaping the niches of animals and for structuring animal communities. We argue that sensory specialization can lower interspecific competition by making the same world appear different. We specifically raise the claim that it is important to consider the interaction of sensory bias and the distribution of (prey) resource size. Using a modeling approach we assessed the potential contribution of sensory bias for species coexistence for the example of bat echolocation. We show that even relatively small sensory differences among coexisting species can translate into significant differences in access to food resources, if prey size distribution is skewed towards small prey. Specifically, for the prey size distribution occurring most frequently in nature, differences in sensory access to resources seem large enough to relax competition and facilitate species coexistence. Interaction between sensory bias and prey size distribution in a way that enhances species coexistence may be a general phenomenon not limited to bat echolocation.

Global warming alters sound transmission: differential impact on the prey detection ability of echolocating bats

“…In the natural world, most bat species that search for prey in open and edge airspace-and rsif.royalsocietypublishing.org J. R. Soc. Interface 11: 20130961 for these, detection volume likely matters the most-use low call frequencies well below 100 kHz [41,42]. Most tropical species of this group are predicted to gain prey detection volume ( figure 2); however, the differences in gain may still alter community composition.…”

“…By contrast, in temperate and arid climates, this shift is predicted to be stronger, because the crossover frequency falls within the frequency range of aerial-hawking bats. In Europe, for example, four to five aerial-hawking species call above the crossover frequency [41] and are predicted to lose prey detection ability, whereas about nine species call around and below f 0 [41] and will have constant or increased detection ability. Even if the disadvantaged species were fully able to compensate for the reduced detection volume, then the enlarged detection volume of the benefiting species might give them an advantage over the sympatric species.…”

Vision in avian emberizid foragers: maximizing both binocular vision and fronto-lateral visual acuity

“…For instance, visual acuity is used to detect predators and binocular vision is used to guide the bill towards food (Martin, 2014). By studying different visual dimensions, particularly in closely related species, we can begin to understand the steps involved in the evolutionary divergence of the avian visual system (Martin, 2012) as well as the role of sensory specializations in gathering specific types of visual information that can be the basis of partitioning foraging resources within ecological niches (Martin and Prince, 2001;Siemers and Swift, 2006;Safi and Siemers, 2010).…”

The simple ears of noctuoid moths are tuned to the calls of their sympatric bat community

“…Larger bats produce lower frequency echolocation calls than smaller bats (Bogdanowicz et al, 1999;Jones, 1999). Higher frequency echolocation calls improve the detection ability for smaller objects (Safi and Siemers, 2010), but acoustic calculations and empirical evidence show that even large bats with low echolocation call frequencies are capable of detecting prey that are smaller than the smallest moths in this study Houston et al, 2004;Jakobsen et al, 2013). Thus, it does not seem likely that the relationship between BF and size in moths is related to their conspicuousness to different bat species using different call frequencies.…”