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| Author(s): |
Maya Romano Maia
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB) |
| Defense date: | 2014-07-15 |
| Examining board members: |
Fernando Ribeiro Gomes;
Denis Otavio Vieira de Andrade;
Patricia Izar Mauro
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| Advisor: | Fernando Ribeiro Gomes |
| Abstract | |
A longstading question in ecophysiology is how behavior buffers environmental challenges in animals. Amphibians loose water at high rates through skin and assume risks when searching for water. We tested if five species of treefrogs differ in water search strategy and whether differences in physiology and in behavior would correlate with temporal distribution and microhabitat choice for reproductive activity. We classified strategies as direct or energetic erratic according to individuals\' activity finding water in a maze. Temporal distribution and microenvironmental conditions related to water availability were recorded associated to males reproductive activity during a year in a same pond. We observed high interspecific differences in treefrogs activity in search for water. Species from genus Hypsiboas demonstrated a clear trend towards direct strategy, taking longer to find water source but being more accurate. Species from Scinax genus were energetic erratic, finding water source sooner by an erratic-active search. Hypsibos bandeirantes, however, had a generalist behavior, exhibiting both strategies. Discriminant analysis indicated that water search strategies had higher discriminative power when associated to temporal distribution of reproductive activity (96.24% correct classification, 100% cross-validated results), with higher dependence of species from direct search strategy to wet season. Within microhabitat variables, energetic erratic strategies could be differentiated by occupying microhabitats with higher humidity. These results suggest that while species with the direct strategy concentrate activity at the wet season peak regardless of microenvironment conditions, energetic erratic species opportunistically call when UR% is very high, independent of the season. Interspecific variation in the physiological variable, the skin resistance to water loss (RWL), can also be discriminated on the basis on temporal distribution (89.4% correct classification, 94.5%. cross-validated results). The lower RWL values (H. albopunctatus < S. crospedospilus < S. hayii) are directly proportional to their dependence to wet season and seems to reflect both adaptation to environmental water availability and phylogenetic inheritance, particularly with species characterized by low RWL tending to call at periods of high water availability. Tests on more species are necessary to confirm this pattern (AU) | |
| FAPESP's process: | 12/15129-6 - Intra-and interspecific variation in microhabitats selection and its relevance to the maintenance of water balance in anurans |
| Grantee: | Maya Romano Maia |
| Support Opportunities: | Scholarships in Brazil - Master |