Cold and dark captivity: Drivers of amphibian longevity

Abstract

Aim Longevity is a critical life‐history trait of organisms. Multiple abiotic and biotic factors are thought to exert different selection pressures, resulting in a great variation in species longevity. We examined factors that, according to evolutionary theories of senescence, are thought to be related to extrinsic and intrinsic mortality rates, and thus shape the variation in longevity among amphibians. Location World‐wide. Time period Present. Major taxa studied Amphibia. Methods We collected literature data on the maximum longevities of 527 amphibian species. Correcting for phylogeny and sample size, we modelled the relationship between amphibian longevity and body size. We also examined the effects of chemical protection, activity period, microhabitat preferences and annual temperature on amphibian longevity. Results In general, members of larger amphibian species live longer. Body size, however, explained less of the variation in amphibian longevity than it does in mammals and birds. Nocturnal amphibians, species that use poison for defence and those inhabiting cold regions live longer, but microhabitat preferences had little effect. Main conclusions Our results supported predictions of evolutionary theories of senescence. Large amphibians living in colder environments probably experience slower growth and metabolic rates, reducing intrinsic drivers of mortality and increasing longevity. Moreover, species that reduce extrinsic mortality pressures via chemical protection and nocturnality have increased longevity. Sampling captive animals and sampling more individuals of a species increases the chances of finding older individuals and should be corrected for when studying maximum longevity.

Climate change and ageing in ectotherms

“…Across‐species comparisons indicate that larger endotherms live longer than smaller ones ( r 2 = .46 and .39 in birds and mammals, respectively; Speakman, 2005). In contrast, body size explains only a small portion of the variance in longevity in vertebrate ectotherms, as observed in amphibians ( r 2 = .07–.14; Stark & Meiri, 2018) or reptiles ( r 2 = .04–.23; Stark, Tamar, Itescu, Feldman, & Meiri, 2018). The weaker correlation between body size and maximum lifespan in vertebrate ectotherms than in endotherms probably indicates that the traits have evolved at least partially independently in species with indeterminate growth.…”

Frogs with denser group-spawning mature later and live longer

“…Alternatively, larger-bodied species have lower basal metabolic rate which is correlated with increased longevity in endotherms 50 . In particular, there are evidences that body size is positively correlated with longevity across taxa in both endotherms and ectotherms 2,4,5,27,30,51 . Body size is positively associated with longevity across amphibians and within the large amphibian orders 4 .…”

“…Most studies have found longevity to be strongly associated with both intrinsic and extrinsic mortality rates in animal kingdoms 2,4,17,28–31 . For example, the use of poison and nocturnality, which ascribe to reduced predation pressure (low extrinsic mortality rate) are associated with longer longevity in amphibians 4 . Stark et al .…”

“…In addition, competition is the other force that drives the evolution of life history 43 . According to life history theory, increasing population size would enhance competition, the K-selected strategy would be favored in this scenario that eventually shapes the whole life history, such as prolonged longevity 12 .Although the factors (e.g., chemical protection, activity period, microhabitat preferences and annual temperature) influencing longevity have been tested formally in amphibians 4,29,44,45 , the relationship between group-spawning and longevity in anurans remains untested.…”

Age and growth in a European flagship amphibian: equal performance at agricultural ponds and favourably managed aquatic sites

“…The age of amphibians exposed to seasonal environments can be determined through skeletochronology (the counting of lines of arrested growth in bone cross sections; for a review see, for example, Sinsch 2015), and a large body of literature using this method has revealed that demographic population structures can vastly differ across latitudes and altitudes both within as well as between species (e.g. Zhang and Lu 2012;Oromí et al 2012;Hjernquist et al 2012;Liao et al 2016;Sinsch and Dehling 2017;Stark and Meiri 2018). Because time-limited growth determines size which in turn is related to fecundity, longevity in amphibians can be interpreted as the result of life history strategies to maximise reproductive output under given constraints (Sinsch et al 2010).…”