Living on the edge: Glucocorticoid physiology in desert iguanas (Dipsosaurus dorsalis) is predicted by distance from an anthropogenic disturbance, body condition, and population density
| Autor: | Henry B. John-Alder, Theodore Garland, Ellen Kohl, Jessica L. Malisch, Lindsey Stevenson, Laurence Claggett |
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| Rok vydání: | 2020 |
| Předmět: |
Male
Physiology 030209 endocrinology & metabolism Population density 03 medical and health sciences 0302 clinical medicine Endocrinology Stress Physiological biology.animal Animals Human Activities Glucocorticoids 030304 developmental biology Population Density 0303 health sciences Habitat fragmentation biology Reproductive success Lizard Road ecology Dipsosaurus dorsalis biology.organism_classification Habitat destruction Habitat Iguanas Female Animal Science and Zoology Corticosterone |
| Zdroj: | General and Comparative Endocrinology. 294:113468 |
| ISSN: | 0016-6480 |
| DOI: | 10.1016/j.ygcen.2020.113468 |
| Popis: | Ecological factors, such as habitat quality, influence the survival and reproductive success of free-living organisms. Urbanization, including roads, alters native habitat and likely influences physiology, behavior, and ultimately Darwinian fitness. Some effects of roads are clearly negative, such as increased habitat fragmentation and mortality from vehicle collision. However, roads can also have positive effects, such as decreasing predator density and increased vegetation cover, particularly in xeric habitats due to increased water run-off. Glucocorticoids are metabolic hormones that reflect baseline metabolic needs, increase in response to acute challenges, and may mediate endogenous resource trade-offs between survival and reproduction. Here we examined circulating concentrations of corticosterone (baseline and stress-induced) in desert iguanas (Dipsosaurus dorsalis) in relation to the distance from a major anthropogenic disturbance, a high-traffic road in Palm Springs, CA. Additionally, we analyzed body condition and population density as additional predictors of glucocorticoid physiology. Surprisingly, we found lower baseline CORT levels closer to the road, but no effect of distance from road on stress-induced CORT or stress responsiveness (difference between baseline and stress-induced concentrations). Both population density and body condition were negative predictors of baseline CORT, stress-induced CORT, and stress responsiveness. Given the known effect of roads to increase run-off and vegetation density, increased water availability may improve available forage and shade, which may then increase the carrying capacity of the habitat and minimize metabolic challenges for this herbivorous lizard. However, it is important to recognize that surfaces covered by asphalt are not usable habitat for iguanas, likely resulting in a net habitat loss. |
| Databáze: | OpenAIRE |
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