Human-Induced Habituation and Landscape Changes at Cultural Heritage Sites Affect the Anti-Predator Behavior of the Aegean Wall Lizard Podarcis erhardii
Slack, Ian
2023-04
Abstract
Predator-prey interactions are among the most common species relationships in nature, and prey will deploy a variety of anti-predator behaviors to manage levels of risk. Human activities can affect predator-prey relationships through both direct and indirect pathways. Here, we examine the expression of a variety of key anti-predator behaviors in a common lizard species, the Aegean wall lizard (Podarcis erhardii, Lacertidae, Reptilia) on the Aegean Island of Naxos (Greece, NE Mediterranean Basin). To do this, we assessed a combination of three complementary anti-predator responses: Flight initiation distance towards humans (FIDH), flight initiation distance towards a mesopredator decoy (FIDD), and field autotomy rates (FAR). Concurrently, we also obtained comprehensive metrics on the local ecosystem such as the relative abundance of humans, predators, prey, and the presence of refugia. We assessed the impact of human presence on the expression of anti-predator behaviors by comparing lizard populations using a paired experimental design in which commonly visited archaeological ruins were ranked by human presence and then divided into comparable sites of high and low human visitation. First, we find that the expression of anti-predator behaviors depends sensitively on the existence of refugia from predation. lizards in areas that offered ample hiding places in the form of stone walls interacted more boldly with potential predators. Furthermore, lizards were able to discriminate between different threats according to their perceived risk and adjust anti-predator behaviors accordingly. Lizards in areas with a higher relative abundance of stone martens (Martes foina), an agile mammalian predator, displayed elevated flight distances relative to areas where this predator was uncommon. In contrast, shyness towards humans declined with increasing human visitation as lizards became habituated to a disrupting, but not particularly dangerous, intruder. Notably, we found that increases in human visitation also resulted in a lessened anti-predator response towards stone martens. Such changes in anti-predatorial capacity are important to document as they can lead to elevated prey mortality as increased human presence results in the deployment of inappropriate anti-predator behaviors. Lastly, tail autotomy of individual lizards was also examined through binary logistic regression and, although not appearing to be significantly influenced by predation, does appear to be determined in part by the extent of human presence. Overall, this study demonstrates that human, predator, and suitable refugia abundance can significantly impact the risk perception of prey. Furthermore, this study highlights the need for further research into the effects pervasive human presence can have on predator-prey interactions.Deep Blue DOI
Subjects
behavior predation ecosystem ecology refugia
Types
Thesis
Metadata
Show full item recordCollections
Remediation of Harmful Language
The University of Michigan Library aims to describe library materials in a way that respects the people and communities who create, use, and are represented in our collections. Report harmful or offensive language in catalog records, finding aids, or elsewhere in our collections anonymously through our metadata feedback form. More information at Remediation of Harmful Language.
Accessibility
If you are unable to use this file in its current format, please select the Contact Us link and we can modify it to make it more accessible to you.