Comparing Plasticity of Response to Perceived Risk in the Textbook Example of Convergent Evolution of Desert Rodents and Their Predators; a Manipulative Study Employing the Landscape of Fear

Abstract

Foragers process information they gain from their surroundings to assess the risk from predators and balance it with the resources in their environment. Measuring these perceived risks from the perspective of the forager can produce a heatmap or their “fear” in the environments, a so-called “landscape of fear” (LOF). In an intercontinental comparison of rodents from the Mojave and Negev Deserts, we set to compare families that are used regularly as examples of convergent evolution, heteromyid and gerbilline respectively. Using a LOF spatial-analysis on data collected from common garden experiments in a semi-natural arena we asked: (1) do all four species understand the risk similarly in the exact same physical environment; (2) does relative relation between species affect the way species draw their LOFs, or does the evolutionary niche of a species have a greater impact on its LOF?; and (3) does predator facilitation between vipers and barn owls cause similar changes to the shape of the measured LOFs. For stronger comparative power we mapped the LOF of the rodents under two levels of risk: low risk (snakes only) and high risk (snakes and barn owls). We found concordance in the way all four species assessed risk in the arena. However, the patterns observed in the LOFs of each rodent family were different, and the way the topographic shape of the LOF changed when owls were introduced varied by species. Specifically, gerbils were more sensitive to owl-related risk than snakes and at the opposite correct for heteromyids. Our findings suggest that the community and environment in which a species evolved has a strong impact on the strategies said animals employ. We also conclude, that given the homogenous landscape we provide in our arena and the non- homogenous patterns of LOF maps, risk assessment can be independent of the physical conditions under which the animals find themselves.

Impact of food availability and predator cues on meadow vole response to social vs. non-social odorants

“…A similar response was found in Arizona pocket mice (Perognathus amplus), Bailey's pocket mice (Perognathus baileyi), and Merriam's Kangaroo rats (Dipodomys merriami) who abandoned food sources more quickly when barn owls (Tyto alba) were present (Brown et al, 1988). Therefore, a prey's change in foraging efforts due to predation pressure may be expected to mediate the impact of predation pressure on conspecific association in a mating context (Pianka, 1976;Koskela & Ylönen, 1995;Bleicher et al, 2018Bleicher et al, , 2019aBleicher et al, , b, 2020.…”

“…Resource availability and the threat of predation can clearly impact conspecific association. However, the occurrence of a predation threat and food deprivation are not necessarily mutually exclusive (Pianka, 1976;Koskela & Ylönen, 1995;Bleicher et al, 2018Bleicher et al, , 2019aBeckmann et al, 2022). The threat of predation can impact the amount of food eaten by prey, and therefore influence the energy available for mating (Pianka, 1976;Koskela & Ylönen, 1995;Bleicher et al, 2018Bleicher et al, , 2020.…”

“…However, elk congregations only occurred in the absence of wolves (Canis lupus), suggesting that the risk, or cost, of predation may be too great for congregations of foraging elk when wolves were present. Research on the impact of predation pressure on mating, grouping, foraging, and the interactions of these variables on prey behaviour is vital to the understanding of the complex behavioural responses of prey during a predation threat (Pianka, 1976;Koskela & Ylönen, 1995;Bleicher et al, 2018Bleicher et al, , 2019aBleicher et al, , b, 2020Haapakoski et al, 2018;Beckmann et al, 2022).…”

Balancing food, activity and the dangers of sunlit nights

“…These include resource competition (e.g., Morris 2003;Ovadia et al 2005) and ambient risk of predation. This risk is manifested in habitat structure (Bleicher 2017), shelter availability (Abu Baker and Brown 2010), the activity of predators in the environment (Bleicher et al , 2019Kotler et al 2016), and the most relevant to our study are ambient illumination (Longland and Price 1991;Kotler et al 2010) including photoperiodic length. Light cycles shift behavioral patterns of foragers and cause variation in stress hormones production .…”

Better safe than sorry: The response to a simulated predator and unfamiliar scent by the European hare

“…Although numerous studies investigated the spatial (Creel et al, 2005) and behavioral (Fendt, 2006) response toward the presence of predators, few studies evaluated a combination of space use and behavior to disentangle the relative importance of different anti‐predator strategies. Moreover, experimental approaches in field settings are important to systematically investigate anti‐predator behaviors (Bleicher, Kotler, & Brown, 2019; Clarke, Reichard, & Zuberbühler, 2012).…”