Ten Principles From Evolutionary Ecology for the Effective Conservation of Reptiles and Amphibians
Reptiles and amphibians are disproportionately threatened among vertebrates but are lagging behind other vertebrate taxa with regards to conservation plans. As the need to triage data-limited species becomes ever more necessary, calls for conservation priorities to be based on evolutionary considerations are increasing. Although there now exists a large body of literature documenting insight that theory can provide to conservation, complex life cycles of many reptiles and amphibians prevents a simple transference of management principles derived from other vertebrate taxa. Thus, there is a need for a set of principles that acknowledges the unique ecology and diversity of herpetofauna. Here we present 10 key principles from evolutionary ecology that can provide rules of thumb to guide management of reptiles and amphibians. Broadly, we identify five landscape-related principles and five life-history–related principles that account for novel ways in which reptiles and amphibians are shaped by the environments they inhabit. When considered in combination they can be useful in providing a holistic view of a species’ status. We hope this paper facilitates identification of species that are in critical need of management intervention and provides a guide for managers and conservation scientists to proactively mitigate extinction risk.ABSTRACT
The range of clutch sizes (top panel) and body sizes (bottom panel) across reptile and amphibian clades, as compared to birds and mammals. Each point represents a species. Body sizes are measured as snout-vent-length (SVL). Amphibian trait data were taken from AmphiBio (Oliveira et al., 2017) and data for reptiles were taken from Meiri et al. (2018). Data for birds and mammals were taken from Myhrvold et al. (2015).
A species’ position in trait space can be used to infer its relative sensitivity to novel sources of mortality. To show the broad range of trait space occupied by reptiles and amphibians, we plot covariance in adult mortality (with age at maturity as a proxy; y-axis) and juvenile mortality (with inverse lifetime fecundity as a proxy; x-axis). Gray points represent species in trait space. We then address the relative effect of the same magnitude of increase in adult mortality on a characteristic species in each corner of the graph. Lines reflecting the deterministic population dynamics are presented for (A) American Bullfrog, Strawberry Poison Dart Frog, and Red-cheeked Salamander, and (B) Leatherback Sea Turtle, Common Chameleon, and European Adder. Steeper drops indicate a stronger effect. A full model description and code used to produce figures are provided in supplementary data. All silhouettes were obtained from Phylopic under a creative commons license.
A species’ position in trait space can be used to infer its vulnerability to novel sources of mortality. To show the range of trait space occupied by reptiles and amphibians, we plot covariance in adult mortality (with age at maturity as a proxy; y-axis) and juvenile mortality (with inverse lifetime fecundity as a proxy; x-axis). Gray points represent species in trait space. We then address the relative effect of 80% reproductive failure on a characteristic species in each corner of the graph. Lines reflecting the deterministic population dynamics are presented for (A) American Bullfrog, Strawberry Poison Dart Frog, and Red-cheeked Salamander, and (B) Green Sea Turtle, Common Chameleon, and European Adder. Steeper drops indicate a stronger effect. A full model description and code used to produce figures are provided as supplementary data. All silhouettes were obtained from Phylopic under a creative commons license.
Sensitivity to increased adult mortality (top panel) and nest failure (bottom panel) for six representative reptiles and amphibians (American Bullfrog, Strawberry Poison Dart Frog, Red-cheeked Salamander, Green Sea Turtle, Common Chameleon, and European Adder). Compensatory capacity is measured as the reproductive potential ratio, i.e., the ratio between the baseline equilibrium population size and the new equilibrium population size following an increase in either adult mortality or nest failure. A full model description and code used to produce figures are provided as supplementary data. All silhouettes were obtained from Phylopic under a creative commons license.
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