Wind constraints on the thermoregulation of high mountain lizards

Abstract

Thermal biology of lizards affects their overall physiological performance. Thus, it is crucial to study how abiotic constraints influence thermoregulation. We studied the effect of wind speed on thermoregulation in an endangered mountain lizard (Iberolacerta aurelioi). We compared two populations of lizards: one living in a sheltered rocky area and the other living in a mountain ridge, exposed to strong winds. The preferred temperature range of I. aurelioi, which reflects thermal physiology, was similar in both areas, and it was typical of a cold specialist. Although the thermal physiology of lizards and the structure of the habitat were similar, the higher wind speed in the exposed population was correlated with a significant decrease in the effectiveness thermoregulation, dropping from 0.83 to 0.74. Our results suggest that wind reduces body temperatures in two ways: via direct convective cooling of the animal and via convective cooling of the substrate, which causes conductive cooling of the animal. The detrimental effect of wind on thermoregulatory effectiveness is surprising, since lizards are expected to thermoregulate more effectively in more challenging habitats. However, wind speed would affect the costs and benefits of thermoregulation in more complex ways than just the cooling of animals and their habitats. For example, it may reduce the daily activity, increase desiccation, or complicate the hunting of prey. Finally, our results imply that wind should also be considered when developing conservation strategies for threatened ectotherms.

An anthropogenic habitat within a suboptimal colonized ecosystem provides improved conditions for a range‐shifting species

“…Despite the cooler conditions provided by docks, the thermal differences observed between habitats were less than the disparity in time spent in the sun would suggest. One possibility is that crabs in the open‐structured salt marsh experience greater convective cooling due to increased wind exposure (Ortega, Mencia, & Perez‐Mellado, ). However, our results suggest that the lower than expected body temperature of crabs in the salt marsh is more likely a result of differences in thermoregulatory behavior.…”

“…Despite the cooler conditions provided by docks, the thermal differences observed between habitats were less than the disparity in time spent in the sun would suggest. One possibility is that crabs in the open-structured salt marsh experience greater convective cooling due to increased wind exposure (Ortega, Mencia, & Perez-Mellado, 2017).…”

Exposure to artificial wind increases energy intake and reproductive performance of female Swiss mice (Mus musculus) under hot temperature

“…Lactating females exposed to wind consumed significantly more food than those that were not; the asymptotic food intake of females exposed to artificial wind was 22.5% (P<0.01) greater than that of controls, and females exposed to wind also had higher gross and digestive energy intake and produced more feces. Wind promotes heat dissipation by convection and evaporation (Porter and Gates, 1969;Winne et al, 2001;Tracy and Christian, 2005;Kearney and Porter, 2009;Ortega et al, 2017), allowing females lactating under hot ambient temperatures to dissipate more body heat. Exposure to wind could therefore decrease the risk of hyperthermia, thereby allowing females to consume more food and produce more milk.…”

“…Wind is a pervasive environmental factor that promotes heat dissipation by convection and evaporation (Porter and Gates, 1969;Winne et al, 2001;Tracy and Christian, 2005;Kearney and Porter, 2009;Ortega et al, 2017). Exposure to wind would therefore be expected to have a non-trivial effect on the reproductive performance of small mammals.…”

Linking behavioral thermoregulation, boldness, and individual state in male Carpetan rock lizards

“…Here, we aimed to test for associations between behavioral thermoregulatory strategy, boldness, and individual state in Carpetan rock lizards ( Iberolacerta cyreni ), a medium‐sized lacertid endemic to mountain ranges in the center of the Iberian Peninsula. Species in the genus Iberolacerta are cold‐adapted lizards living mainly in low thermal quality environments (Aguado & Braña, 2014; Carrascal, López, Martín, & Salvador, 1992; Jiménez‐Robles & De la Riva, 2019; Monasterio, Salvador, Iraeta, & Díaz, 2009; Ortega, Federal, & Grosso, 2017; Ortega, Mencía, & Pérez‐Mellado, 2017; Žagar, Carretero, Osojnik, Sillero, & Vrezec, 2015). Recent empirical data on I. cyreni indicate the existence of animal personality in different behavioral traits, with short‐term differences in state and environment potentially contributing to between‐individual behavioral variation (Horváth et al., 2016; Horváth, Martín, et al, 2017; Horváth, Mészáros, et al, 2017; López, Hawlena, Polo, Amo, & Martín, 2005).…”