TY  - JOUR
A1  - Grimm-Seyfarth, Annegret
A1  - Mihoub, Jean-Baptiste
A1  - Gruber, Bernd
A1  - Henle, Klaus
T1  - Some like it hot
BT  - from individual to population responses of an arboreal arid-zone gecko to local and distant climate
JF  - Ecological monographs
N2  - Accumulating evidence has demonstrated considerable impact of climate change on biodiversity, with terrestrial ectotherms being particularly vulnerable. While climate-induced range shifts are often addressed in the literature, little is known about the underlying ecological responses at individual and population levels. Using a 30-yr monitoring study of the long-living nocturnal gecko Gehyra variegata in arid Australia, we determined the relative contribution of climatic factors acting locally (temperature, rainfall) or distantly (La Nina induced flooding) on ecological processes ranging from traits at the individual level (body condition, body growth) to the demography at population level (survival, sexual maturity, population sizes). We also investigated whether thermoregulatory activity during both active (night) and resting (daytime) periods of the day can explain these responses. Gehyra variegata responded to local and distant climatic effects. Both high temperatures and high water availability enhanced individual and demographic parameters. Moreover, the impact of water availability was scale independent as local rainfall and La Nina induced flooding compensated each other. When water availability was low, however, extremely high temperatures delayed body growth and sexual maturity while survival of individuals and population sizes remained stable. This suggests a trade-off with traits at the individual level that may potentially buffer the consequences of adverse climatic conditions at the population level. Moreover, hot temperatures did not impact nocturnal nor diurnal behavior. Instead, only cool temperatures induced diurnal thermoregulatory behavior with individuals moving to exposed hollow branches and even outside tree hollows for sun-basking during the day. Since diurnal behavioral thermoregulation likely induced costs on fitness, this could decrease performance at both individual and population level under cool temperatures. Our findings show that water availability rather than high temperature is the limiting factor in our focal population of G.variegata. In contrast to previous studies, we stress that drier rather than warmer conditions are expected to be detrimental for nocturnal desert reptiles. Identifying the actual limiting climatic factors at different scales and their functional interactions at different ecological levels is critical to be able to predict reliably future population dynamics and support conservation planning in arid ecosystems.
KW  - behavioral adaptation
KW  - body condition
KW  - body growth rate
KW  - climate change
KW  - El Nino Southern Oscillation (ENSO)
KW  - Gehyra variegata
KW  - population dynamics
KW  - population size
KW  - survival
KW  - thermoregulation
Y1  - 2018
U6  - https://doi.org/10.1002/ecm.1301
SN  - 0012-9615
SN  - 1557-7015
VL  - 88
IS  - 3
SP  - 336
EP  - 352
PB  - Wiley
CY  - Hoboken
ER  -