10.6084/m9.figshare.11347007.v1
Gavin Stark
Gavin
Stark
Rachel Schwarz
Rachel
Schwarz
Shai Meiri
Shai
Meiri
Does nocturnal activity prolong gecko longevity?
Brill Online
2019
activity time
body size
Gekkota
intrinsic mortality
lizards
metabolic rate
solar radiation
Ecology not elsewhere classified
2019-12-27 07:50:44
Journal contribution
https://brill.figshare.com/articles/journal_contribution/Does_nocturnal_activity_prolong_gecko_longevity_/11347007
The majority of lizard clades are ancestrally and predominantly diurnal.
The only major taxon in which most species are nocturnal is the Gekkota (geckos
and pygopodids). As ectothermic thermoregulators, lizard metabolic rates are
highly temperature dependent, and diurnal lizards therefore demonstrate higher metabolic
rates than nocturnal ones. Furthermore, exposure to solar radiation is thought
to reduce ectothermic longevity by increasing both metabolic costs and the rate of
accumulating harmful mutations through UV radiation (UVC specifically). In being nocturnal, ectothermic species may reduce their intrinsic mortality rates and thus
live longer. To test this hypothesis, we collected literature data on the maximum longevities of 740 lizard
species, of which 185 are geckos. We examined whether geckos live longer than
other lizards, and whether activity time affects gecko longevity. While geckos
live relatively long for lizards of their size, their activity time was found to be unrelated to
longevity, contradicting our predictions. We suggest that diurnal
species may have evolved higher resistance to UV radiation via thicker, more
keratinized skin. Elevated metabolic rates do not automatically equate with
faster aging. Mortality through extrinsic causes (e.g., predation) may impose
much stronger selective pressures than intrinsic causes.