title: Thermal ecological physiology of native and invasive frog species: do invaders perform better?
abstract: Biological invasions are recognized as an important biotic component of global change that threatens the composition, structure and functioning of ecosystems, resulting in loss of biodiversity and displacement of native species. Although ecological characteristics facilitating the establishment and spread of non-native species are widely recognized, little is known about organismal attributes underlying invasion success. In this study, we tested the effect of thermal acclimation on thermal tolerance and locomotor performance in the invasiveXenopus laevisand the Chilean nativeCalyptocephalella gayi. In particular, the maximal righting performance (μMAX), optimal temperature (TO), lower (CTmin) and upper critical thermal limits (CTmax), thermal breadth (Tbr) and the area under the performance curve (AUC) were studied after 6 weeks acclimation to 10 and 20°C. We observed higher values of μmaxand AUC inX. laevisin comparison toC. gayi. On the contrary, the invasive species showed lower values of CTminin comparison to the native one. In contrast, CTmax,TOandTbrshowed no inter-specific differences. Moreover, we found that both species have the ability to acclimate their locomotor performance and lower thermal tolerance limit at low temperatures. Our results demonstrate thatX. laevisis a better performer thanC. gayi. Although there were differences in CTmin, the invasive and native frogs did not differ in their thermal tolerance. Interestingly, in both species the lower and upper critical thermal limits are beyond the minimal and maximal temperatures encountered in nature during the coldest and hottest month, respectively. Overall, our findings suggest that bothX. laevisandC. gayiwould be resilient to climate warming expectations in Chile.
authors.affiliation: Departamento de Ecología, Center of Applied Ecology & Sustainability (CAPES), Facultad de Ciencias Biológicas , Pontificia Universidad Católica de Chile , Santiago 6513677 , Chile .
authors.forename: Pablo A
authors.initials: PA
authors.lastname: Cortes
authors.affiliation: Departamento de Ecología, Center of Applied Ecology & Sustainability (CAPES), Facultad de Ciencias Biológicas , Pontificia Universidad Católica de Chile , Santiago 6513677 , Chile .
authors.forename: Hans
authors.initials: H
authors.lastname: Puschel
authors.affiliation: Departamento de Ciencias Básicas , Universidad Santo Tomás , Santiago , Chile .
authors.forename: Paz
authors.initials: P
authors.lastname: Acuña
authors.affiliation: Instituto de Ciencias Ambientales y Evolutivas, Facultad de Ciencias , Universidad Austral de Chile, Campus Isla Teja, Valdivia , Chile .
authors.forename: José L
authors.initials: JL
authors.lastname: Bartheld
authors.affiliation: Departamento de Ecología, Center of Applied Ecology & Sustainability (CAPES), Facultad de Ciencias Biológicas , Pontificia Universidad Católica de Chile , Santiago 6513677 , Chile .
authors.forename: Francisco
authors.initials: F
authors.lastname: Bozinovic
keywords: Acclimation; amphibians; central Chile; invasive species; thermal performance curve; thermal tolerance