Relations between environmental and physiological conditions of activity and its importance for the distribution alterations of toads with climatic changes

• Grant number: 16/01782-0
• Support type: Scholarships in Brazil - Post-Doctorate
• Effective date (Start): May 01, 2017
• Effective date (End): November 30, 2020
• Field of knowledge: Biological Sciences - Ecology
• Cooperation agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Carlos Arturo Navas Iannini
• Grantee: Braz Titon Junior
• Home Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 14/16320-7 - Impacts of climate/environmental change on the fauna: an integrative approach, AP.PFPMCG.TEM

Abstract

Temperature rise due to global climate change is one of the main responsible for species redistribution in all biomes and ecosystems. When physiological adjustments or genetic adaptation are not enough to support the environmental changes in a given population, the extinction probability rises. Among lizards, extinction can reach 16% to 30% of species between 2050 and 2080. This function for predicting changes in patterns of distribution and/or extinction in lizards was modeled from physiological performance curves as a function of temperature, and temperature characteristics of occurrence points of the species. For amphibians, water availability and temperature seem to be very consistent factors determining the occurrence of the species. Despite the existence of physiological data related to water balance and performance curves considering temperature and hydration level for some species, there are no observational data on weather conditions in which these animals are active in nature, as well as on the possible higric and thermal restrictions offered by the environments. In addition, body and immunological conditions associated with stress may be indicative of activity restriction. The objective of this study is to investigate possible macro and microclimatic differences determining patterns of activity for Rhinella, and also, investigate the relations between physiological and environmental conditions of activity. In addition, this study will provide bases for the development of distribution models based on climate change scenarios to assess risk situations for this group, incorporating both performance curves described in the literature and possible environmental constraints resulting from global warming. To do so, environmental and physiological conditions of activity will be investigated for Rhinella species in fragments differing in degrees of degradation. This investigation will be performed by monitoring body temperature, dehydration rates, voluntary tolerance to dehydration and climatic conditions (temperature, relative Humidity and precipitation) e by collecting blood sample and measuring corticosterone levels and evaluating immunological condition. (AU)