Hunt or hide: How insularity and urbanization affect foraging decisions in lizards

Abstract

Foraging decisions should reflect a balance between costs and benefits of alternative strategies. Predation risk and resource availability in the environment may be crucial in deciding how cautious individuals should behave during foraging. These costs and benefits will vary in time and context, meaning that animals should be able to adjust their foraging behaviour to new or altered environments. Studying how animals do this is essential to understand their survival in these environments. In this study, we investigated the effect of both insularity and urbanization on risk‐taking and neophobia during foraging in the Dalmatian wall lizard (Podarcis melisellensis). Small islets tend to have both a lower number of predators and less resources. Therefore, islet populations were expected to show more risk‐taking behaviour and less neophobia in a foraging context. Previous studies on behaviour of urban lizards have yielded inconsistent results, but due to a lack of both predators and arthropod prey in urban habitats, we expected urban lizards to also take more risks and behave less neophobic. We sampled several inhabited and uninhabited locations on Vis (Croatia) and surrounding islets. Risk‐taking behaviour was tested by measuring the latency of lizards to feed in the presence of a predator model, and neophobia by measuring the latency to feed in the presence of a novel object. We found that islet lizards do indeed take more risks and were less vigilant, but not less neophobic. Urban and rural lizards did not differ in any of these behaviours, which is in sharp contrast with previous work on mammals and birds. The behavioural differences between islet and island lizards were novel, but not unexpected findings and are in line with the theory of “island tameness”. The effect of urbanization on the behaviour of animals seems to be more complex and might vary among taxa.

Parental habituation to human disturbance over time reduces fear of humans in coyote offspring

“…We quantified risk‐taking behavior as the willingness to forage with persistent human disturbance (i.e., human observer). This is similar to previous studies that assess individual differences in risk‐taking and boldness in relation to anthropogenic disturbance (Dammhahn & Almeling, ; De Meester et al, ; Greenberg & Holekamp, ; Patrick, Charmantier, & Weimerskirch, ; Samia, Nakagawa, Nomura, Rangel, & Blumstein, ). Second, we predicted that second‐litter pups would be less risk‐averse than their first‐litter siblings.…”

“…This is likely due to strong parental influence, in which parental habituation level is an ever‐present cue that offspring use to modify their fear responses toward humans. It remains unclear, however, whether reductions in fear of humans have fitness consequences for developing coyotes in the wild, as is the case for other taxa (De Meester et al, ; Hall et al, ). In addition, it is still uncertain whether such traits observed during development are consistent across multiple life stages.…”

How to behave when marooned: the behavioural component of the island syndrome remains underexplored

“…avoidance and inspection of predator models, startles, latency to resume feeding) when confronted with varied threat stimuli (e.g. predator cues, loud noise and novel objects) (see [ 31 ] for a review of techniques; and [ 60 – 63 ] for examples in island–mainland comparison).…”

“…avoidance and inspection of predator models, startles, latency to resume feeding) when confronted with varied threat stimuli (e.g. predator cues, loud noise and novel objects) (see [31] for a review of techniques; and [60][61][62][63] for examples in island-mainland comparison). Increased boldness on islands is typically attributed to reduced predation pressure, although quantitative or even qualitative estimates thereof are seldom presented.…”