In this study, we simulated predation on P. Powdered individuals of P. On each night, ground and off-ground traps were left out for equal lengths of time 2—6 h.
First, we assumed, as did Fraser and Maerz et al. Hungry three-spined sticklebacks, for example, feed in the denser portions of swarms of prey where predation risk is higher, whereas partially satiated sticklebacks feed in the safer, less dense edges of prey swarms Milinski and Heller ; Heller and Milinski We then released the salamander where we had found it.
We took note of the time between powdering the salamander and observation of its trail T. Full models included all interaction terms derived from the independent variables.
For each trail, we also measured the maximum displacement Dthat is, the straight linear distance between the salamander capture location and the mark furthest from that location.
Control individuals were measured, dipped in powder, and released with their tails intact. Each organism was placed into 1 of 6 size classes based on body length see Table 1.
Sampling was performed along forest transects systematically with no location sampled twice in order to avoid reusing the same salamander on multiple nights and to avoid confusing old and current powder trails. This physical limitation is unlikely to have affected our results because very few observed marks even approached this height.
Between andwe located salamanders under logs and rocks, except on 6 occasions when salamanders were located after dark; we found these salamanders foraging on leaf litter. Plethodon cinereus, the red-backed salamander, is potentially a good model species for studying predation risk in terrestrial species because it occupies distinct nocturnal habitats: Animals select microhabitats for a variety of reasons.
Marks that may have been left on plants above cm were not recorded because they were too high for the observer to find. Advanced Search Abstract Animals select microhabitats based on food availability, physiological cost, and mortality risk relative to other available habitats.
Models that take into account a trade-off between predation risk and foraging success tend to have the most explanatory power Gilliam and Fraser ; Railsback and Harvey Nighttime predators of P.
Terrestrial field studies, which have the advantage of addressing habitat selection under natural conditions, usually either describe risk—foraging trade-offs in more basic terms e. We conclude that salamanders use the plant habitat as a refuge from predation despite reduced foraging potential and increased physiological cost.
On each night, one of the traps was on the ground, with the rest of the traps off the ground, because in preliminary studies we found that off-ground traps captured significantly lower numbers of insects than on-ground traps; more traps improved the accuracy of our estimate for off-ground prey abundance.
Finally, we conducted observations of unmanipulated individuals of P. In the 3 tests with a climbing parameter as the dependent variable, we used SVL, D, and T as covariates.
We investigated the effect of simulated predation on microhabitat use in light of differences in prey availability in Plethodon cinereus, a small terrestrial salamander which displays nighttime plant-climbing behavior.
Typical taxa included flies, collembolans, lepidopterans adult and larvalbeetles, orthopterans, as well as arachnids mites and harvestmen.
This suggests that dehydration may physiologically constrain their microhabitat selection during nighttime foraging.Resource Depletion and Habitat Segregation by Competitors Under Predation Hazard () Habitat selection under predation hazard: test of a model with foraging minnows.
Ecology – () Resource Depletion and Habitat Segregation by Competitors Under Predation Hazard. In: Ebenman B., Persson L. (eds) Size. Habitat Selection Under Predation Hazard: Test of a Model with Foraging Minnows.
Variation and drivers of airflow patterns associated with olfactory concealment and habitat selection, Ecology, 99, 2, (), Feeding under Predation Hazard. Behavioral Ecology, Volume 19, Issue 3, 1 MayPages –, Terrestrial field studies, which have the advantage of addressing habitat selection under natural conditions, Habitat selection under predation hazard: test of.
Resource Depletion and Habitat Segregation Under Predation To determine whether the use of space by the guppy population can be altered during periods in which guabine are present, we selected an upstream pool, 2 m.
Gilliam JF, Fraser DF () Habitat selection under predation hazard: test of a model with foraging minnows. Ecology – CrossRef Google Scholar Gilliam JF. We tested the hypotheses that Lyngbya is an effective refuge from Bluegill Sunfish (Lepomis macrochirus) predation and that predator cues modify habitat selection by amphipods.
In no-choice assays, amphipods exposed to fish predation showed higher survivorship on Lyngbya than on Rhizoclonium.Download