Toward a community ecology of landscapes: predicting multiple predator–prey interactions across geographic space

Abstract

Community ecology was traditionally an integrative science devoted to studying interactions between species and their abiotic environments in order to predict species' geographic distributions and abundances. Yet for philosophical and methodological reasons, it has become divided into two enterprises: one devoted to local experimentation on species interactions to predict community dynamics; the other devoted to statistical analyses of abiotic and biotic information to describe geographic distribution. Our goal here is to instigate thinking about ways to reconnect the two enterprises and thereby return to a tradition to do integrative science. We focus specifically on the community ecology of predators and prey, which is ripe for integration. This is because there is active, simultaneous interest in experimentally resolving the nature and strength of predator-prey interactions as well as explaining patterns across landscapes and seascapes. We begin by describing a conceptual theory rooted in classical analyses of non-spatial food web modules used to predict species interactions. We show how such modules can be extended to consideration of spatial context using the concept of habitat domain. Habitat domain describes the spatial extent of habitat space that predators and prey use while foraging, which differs from home range, the spatial extent used by an animal to meet all of its daily needs. This conceptual theory can be used to predict how different spatial relations of predators and prey could lead to different emergent multiple predator-prey interactions such as whether predator consumptive or non-consumptive effects should dominate, and whether intraguild predation, predator interference or predator complementarity are expected. We then review the literature on studies of large predator-prey interactions that make conclusions about the nature of multiple predator-prey interactions. This analysis reveals that while many studies provide sufficient information about predator or prey spatial locations, and thus meet necessary conditions of the habitat domain conceptual theory for drawing conclusions about the nature of the predator-prey interactions, several studies do not. We therefore elaborate how modern technology and statistical approaches for animal movement analysis could be used to test the conceptual theory, using experimental or quasi-experimental analyses at landscape scales.

Tritrophic interactions between a fungal pathogen, a spider predator, and the blacklegged tick

“…Boxes extend the interquartile range (IQR) from 25th to 75th percentile, and whiskers from IQR to 1.5*IQR, outliers are plotted individually TA B L E 6 Summary of the fitted model of the proportion of questing nymphs, relative to the number of nymphs that survived, including effects of spider treatment, spider survival, and spider activity at time of observation. There was a significant effect of spider activity cues from S. ocreata influence questing behavior or fitness of ticks (Schmitz, Miller, Trainor, & Abrahms, 2017). Chemotactile cues provide a possible mechanism by which ticks may modify their questing behavior in response to S. ocreata.…”

“…Web of Science searches (for “Ixod* AND preda*”; “Ixod* AND prey”; “Ixod* and “trait‐mediated”; Ixod* AND “nonconsumptive”) returned no prior studies reporting antipredator behavior in ticks. Further experiments would enable testing whether chemotactile cues from S. ocreata influence questing behavior or fitness of ticks (Schmitz, Miller, Trainor, & Abrahms, ). Chemotactile cues provide a possible mechanism by which ticks may modify their questing behavior in response to S. ocreata .…”

Habitat complexity mediates the predator–prey space race

“…, Schmitz et al. ). However, when prey depend on a limited and patchy food resource they may be forced to endure higher spatial overlap with predators, as predators are able to readily predict prey location (Sih ).…”

“…When predators are confined to a narrow habitat domain to hunt successfully, prey can readily avoid them, resulting in strong spatial antipredator behavior (Hugie and Dill , Heithaus , Schmitz et al. ). Any limitation on predator hunting conditions (i.e., required stalking cover) allows prey to mitigate their predation risk by utilizing areas where predator hunting efficacy is diminished (Sih , Cresswell et al.…”

Predator, prey, and substrate interactions: the role of faunal activity and substrate characteristics

“…Predation and the associated behavior of both predator and prey are important drivers of evolutionary change (Vermeij 1982), with predator-prey interactions receiving considerable research attention (e.g., Heck and Crowder 1991, Chivers and Smith 1998, Schmitz et al 2017. Many species display a repertoire of strategies and defense mechanisms to reduce the risks associated with predation that reflect adaptations developed over millennia (Strauss et al 2006, Belgrad and Griffen 2016, Alberti et al 2017.…”