Separating effects of spatial location and microhabitat density on perceived predation risk in small mammals

2021 ◽  
Author(s):  
K. N. Denny ◽  
K. N. Bilodeau ◽  
C. A. Dumont ◽  
Z. H. Olson
Keyword(s):  
Predation Risk ◽  
Small Mammals ◽  
Spatial Location ◽  
Perceived Predation Risk

scholarly journals Shrub cover homogenizes small mammals’ activity and perceived predation risk

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Anne A. Loggins ◽  
Adrian M. Shrader ◽  
Ara Monadjem ◽  
Robert A. McCleery
Keyword(s):  
Predation Risk ◽  
Small Mammals ◽  
Vegetation Structure ◽  
Shrub Cover ◽  
African Savanna ◽  
Use Of Space ◽  
Disturbance Regimes ◽  
Woody Cover ◽  
Animal Communities ◽  
Perceived Predation Risk

AbstractAltered disturbance regimes, increasing atmospheric CO2, and other processes have increased woody cover and homogenized vegetation in savannas across the planet. African savannas with extensive versus minimal woody cover often have vastly different animal communities. However, we lack a clear mechanistic understanding of why animal communities are changing with vegetation structure. Our goal for this study was to understand how vegetation structure in an African savanna shaped the perceived predation risk of small mammals, hence affecting their activity. Using a reciprocal measure of standard giving-up-densities, amount of food eaten, we found sharp declines in rodents’ perceived predation risk and increased rodent activity underneath shrub cover. This response was consistent across species; however, species showed subtle differences in their responses to grassy vegetation. Our findings suggest that areas of minimal or extensive shrub cover (shrub encroachment) may be homogenizing rodents’ perceptions of predation risk and thus shaping their use of space.

Perceived predation risk, parasitism, and the foraging behavior of a freshwater snail (Potamopyrgus antipodarum)

1998 ◽  
Vol 76 (10) ◽  
pp. 1878-1884 ◽  
Author(s):  
Edward P Levri
Keyword(s):  
Predation Risk ◽  
Foraging Behavior ◽  
Freshwater Snail ◽  
Potamopyrgus Antipodarum ◽  
Plain Water ◽  
Fish Diet ◽  
Fish Predator ◽  
Size Dependent ◽  
Individual Size ◽  
Perceived Predation Risk

Foraging behavior can be influenced by such factors as predation risk, individual size, and parasite infection. Snails (Potamopyrgus antipodarum) placed in tanks with large rocks were exposed to four types of water: (1) water with crushed snails, (2) water from a tank in which fish (Gobiomorphus cotidianus) were fed only trout chow, (3) water from a tank where the fish were also fed snails, and (4) plain water. Snails could respond by moving to the top of rocks (where algal food was present) or to the bottom of rocks (where the predation risk was lower). The snails responded to fish chemicals by moving to the bottom of rocks. The response was dependent on snail size and fish diet. Smaller snails moved to the bottom of rocks more than larger snails did. Trematode-infected snails were found on top of the rocks more than other classes of snails, but infected snails still moved to the bottom of rocks in response to the fish predator. Snails eaten by fish in the field tend to be smaller than snails in the overall available population. Thus, snails that are more vulnerable to predation respond more intensely to the odor of fish by moving to the bottom of rocks. This size-dependent response to fish appears to be independent of the occurrence of trematode infection.

Functional Traits, Flocking Propensity, and Perceived Predation Risk in an Amazonian Understory Bird Community

2016 ◽  
Vol 187 (5) ◽  
pp. 607-619 ◽  
Author(s):  
Ari E. Martínez ◽  
Juan P. Gomez ◽  
José Miguel Ponciano ◽  
Scott K. Robinson
Keyword(s):  
Predation Risk ◽  
Functional Traits ◽  
Bird Community ◽  
Perceived Predation Risk

scholarly journals Spatial ecology of perceived predation risk and vigilance behavior in white-faced capuchins

2014 ◽  
Vol 25 (3) ◽  
pp. 477-486 ◽  
Author(s):  
Fernando A. Campos ◽  
Linda M. Fedigan
Keyword(s):  
Predation Risk ◽  
Spatial Ecology ◽  
Vigilance Behavior ◽  
Perceived Predation Risk

scholarly journals Scavenging and the ecology of fear: do animal carcasses create islands of risk on the landscape?

2018 ◽  
Vol 96 (3) ◽  
pp. 229-236 ◽  
Author(s):  
C.M. Steinbeiser ◽  
C.A. Wawrzynowski ◽  
X. Ramos ◽  
Z.H. Olson
Keyword(s):  
Small Mammals ◽  
Small Mammal ◽  
Human Error ◽  
Seedling Survival ◽  
Castor Canadensis ◽  
Trophic Levels ◽  
Risk Effects ◽  
Low Levels ◽  
Perceived Predation Risk ◽  
Predator Effects

Many vertebrate scavengers function as predators in ecosystems, suggesting that the presence of scavengers and occurrence of predator effects may be intertwined near carcasses. We tested for risk effects near a series of experimentally placed carcasses by measuring small-mammal foraging in a before–after control–impact design. Validation efforts revealed low levels of food loss from stations due to human error and invertebrate foraging, and habituation to stations occurred after 2 weeks. Increased perceived predation risk by small mammals relative to controls occurred in three of seven trials. The effect was observed across tested carcass types (beaver, Castor canadensis Kuhl, 1820; white-tailed deer, Odocoileus virginianus (Zimmermann, 1780)) and seasons (summer and fall). However, small mammals also increased foraging relative to controls in two of seven trials, and foraging reached a ceiling in two other trials that prevented inference on a response. Taken together, our results suggest that scavenger recruitment to carcasses can in some instances create islands of risk for prey on the landscape, but the effect is not likely to be universal. Where small-mammal foraging does decrease, further work will be necessary to determine if risk effects cascade to adjacent trophic levels through enhanced seed and seedling survival.

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