Habitat use by female desert tortoises suggests tradeoffs between resource use and risk avoidance.

Autor: Nafus MG; Department of Wildlife, Fish and Conservation Biology, University of California, Davis, Davis, CA, United States of America., Daly JA; University of Georgia's Savannah River Ecology Lab, Aiken, SC, United States of America., Tuberville TD; University of Georgia's Savannah River Ecology Lab, Aiken, SC, United States of America., Klimely AP; Department of Wildlife, Fish and Conservation Biology, University of California, Davis, Davis, CA, United States of America., Buhlmann KA; University of Georgia's Savannah River Ecology Lab, Aiken, SC, United States of America., Todd BD; Department of Wildlife, Fish and Conservation Biology, University of California, Davis, Davis, CA, United States of America.
Jazyk: angličtina
Zdroj: PloS one [PLoS One] 2022 Aug 19; Vol. 17 (8), pp. e0263743. Date of Electronic Publication: 2022 Aug 19 (Print Publication: 2022).
DOI: 10.1371/journal.pone.0263743
Abstrakt: Animals may select habitat to maximize the benefits of foraging on growth and reproduction, while balancing competing factors like the risk of predation or mortality from other sources. Variation in the distribution of food resources may lead animals to forage at times or in places that carry greater predation risk, with individuals in poor quality habitats expected to take greater risks while foraging. We studied Mojave desert tortoises (Gopherus agassizii) in habitats with variable forage availability to determine if risk aversion in their selection of habitat relative was related to abundance of forage. As a measure of risk, we examined tortoise surface activity and mortality. We also compared tortoise body size and body condition between habitats with ample forage plants and those with less forage plants. Tortoises from low forage habitats selected areas where more annual plants were nutritious herbaceous flowering plants but did not favor areas of greater perennial shrub cover that could shelter them or their burrows. In contrast, tortoises occupying high forage habitats showed no preference for forage characteristics, but used burrows associated with more abundant and larger perennial shrubs. Tortoises in high forage habitats were larger and active above ground more often but did not have better body condition. Mortality was four times higher for females occupying low forage habitat than those in high forage habitat. Our results are consistent with the idea that tortoises may minimize mortality risk where food resources are high, but may accept some tradeoff of greater mortality risk in order to forage optimally when food resources are limiting.
Competing Interests: The authors have declared that no competing interests exist.
Databáze: MEDLINE
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