As a group [reptiles] are neither ‘good’ nor ‘bad,’ but iare interesting and unusual, although of minor importance. If they should all disappear, it would not m

Reports of declining amphibian populations in many parts of the world are numerous, but supporting long-term census data are generally unavailable. Census data from 1979 to 1990 for three salamander species and one frog species at a breeding pond in South Carolina showed fluctuations of substantial magnitude in both the size of breeding populations and in recruitment of juveniles. Breeding population sizes exhibited no overall trend in three species and increased in the fourth. Recent droughts account satisfactorily for an increase in recruitment failures. These data illustrate that to distinguish between natural population fluctuations and declines with anthropogenic causes may require long-term studies.

Biological responses to climate change have been widely documented across taxa and regions, but it remains unclear whether species are maintaining a good match between phenotype and environment, i.e. whether observed trait changes are adaptive. Here we reviewed 10,090 abstracts and extracted data from 71 studies reported in 58 relevant publications, to assess quantitatively whether phenotypic trait changes associated with climate change are adaptive in animals. A meta-analysis focussing on birds, the taxon best represented in our dataset, suggests that global warming has not systematically affected morphological traits, but has advanced phenological traits. We demonstrate that these advances are adaptive for some species, but imperfect as evidenced by the observed consistent selection for earlier timing. Application of a theoretical model indicates that the evolutionary load imposed by incomplete adaptive responses to ongoing climate change may already be threatening the persistence of species.

Climate change has had a significant impact globally on the timing of ecological events such as reproduction and migration in many species. Here, we examined the phenology of reproductive migrations in 10 amphibian species at a wetland in South Carolina, USA using a 30 year dataset. We show for the first time that two autumn-breeding amphibians are breeding increasingly later in recent years, coincident with an estimated 1.2°C increase in local overnight air temperatures during the September through February pre-breeding and breeding periods. Additionally, two winter-breeding species in the same community are breeding increasingly earlier. Four of the 10 species studied have shifted their reproductive timing an estimated 15.3 to 76.4 days in the past 30 years. This has resulted in rates of phenological change that range from 5.9 to 37.2 days per decade, providing examples of some of the greatest rates of changing phenology in ecological events reported to date. Owing to the opposing direction of the shifts in reproductive timing, our results suggest an alteration in the degree of temporal niche overlap experienced by amphibian larvae in this community. Reproductive timing can drive community dynamics in larval amphibians and our results identify an important pathway by which climate change may affect amphibian communities.