Papers by Débora L Moreno Azócar
Zoology, 2015
Please cite this article in press as: Bonino, M.F., et al., Thermal sensitivity of cold climate l... more Please cite this article in press as: Bonino, M.F., et al., Thermal sensitivity of cold climate lizards and the importance of distributional ranges. Zoology (2015), http://dx.
Journal of Zoology, 2014
Body size (BS) varies in response to several selective pressures. In ectotherms, thermal inertia ... more Body size (BS) varies in response to several selective pressures. In ectotherms, thermal inertia may affect thermoregulation, since larger BSs increase heat conservation as Bergmann originally stipulated for endotherms. However, Bergmann's rule is controversial in ectotherms. The heat balance hypothesis states that ectotherms' thermoregulatory capability is relevant for trends in BS. In cold climates, larger BSs would be advantageous for small thermoregulating ectotherms, by increasing heat conservation. However, BS implies a delaying effect on heating too; therefore, ectotherms may need another trait to compensate the later effect. Thermal melanism hypothesis posits that melanism increases heat gain, and may be adaptive for animals inhabiting cold climates. We propose that the higher solar radiation absorption from increased melanism may be such a compensatory trait. We expect BS and melanism to increase with latitude in response to seasonal temperatures and solar radiation. To test this, we studied the monophyletic Liolaemus goetschi group of lizard species across its 2200 km (32-48°S latitude) range. We used phylogenetically informed analyses to study geographic variation of BS and melanism (dorsal, ventral and total) in relation to temperatures, thermal amplitude, cloudiness and net solar radiation. Our results show that lizards' BS increases latitudinally in relation to thermal amplitude and temperature. Only ventral melanism varied latitudinally, but all melanism variables varied in response to cloudiness and net radiation. The relationship between BS and melanism was significant and positive in all cases. We suggest thermal inertia may be a fair candidate mechanism explaining geographic variation in BS (heat balance hypothesis), while melanism may influence heat gain according to the thermal melanism hypothesis. However, it remains unclear why latitudinal variation is related to ventral instead of dorsal melanism, and further investigation is needed to clarify the relationship between BS and melanism in light of cold climates.
Regional Environmental Change, 2014
Ectothermic organisms strongly depend on temperature, making them an excellent model to study the... more Ectothermic organisms strongly depend on temperature, making them an excellent model to study the impact of global climatic change (GCC). Under global warming, species may be forced to move toward colder environments, such as higher latitudes, higher elevations or both. However, several studies show that responses may vary significantly in different groups of species. Therefore, it is unclear whether species' current distribution range sizes will be affected in future climatic scenarios. In addition to the specific possible effect of range size changes, the potential consequences of distributional range shifts also should be considered. Here, our aim is to assess whether GCC may affect a group of Liolaemus lizard species based on their current geographic distribution range size and whether the effect is uniform across all species using species distribution models (SDMs). Our results show that range boundaries of the fourteen species switch toward higher altitude and latitude in future scenarios. Additionally, there is not a unique pattern in terms of increase or decrease in potential range for lizards in Patagonia in future scenarios. Finally, our results show that the original distribution range size is determinant for the resultant SDMs projections, suggesting that species with a high degree of endemicity may be susceptible to a greater impact of GCC.
Oecologia, 2013
The importance of the thermal environment for ectotherms and its relationship with thermal physio... more The importance of the thermal environment for ectotherms and its relationship with thermal physiology and ecology is widely recognized. Several models have been proposed to explain the evolution of the thermal biology of ectotherms, but experimental studies have provided mixed support. Lizards from the Liolaemus goetschi group can be found along a wide latitudinal range across Argentina. The group is monophyletic and widely distributed, and therefore provides excellent opportunities to study the evolution of thermal biology. We studied thermal variables of 13 species of the L. goetschi group, in order to answer three questions. First, are aspects of the thermal biology of the L. goetschi group modelled by the environment or are they evolutionarily conservative? Second, have thermal characteristics of these animals co-evolved? And third, how do the patterns of co-evolution observed within the L. goetschi group compare to those in a taxonomically wider selection of species of Liolaemus? We collected data on 13 focal species and used species information of Liolaemus lizards available in the literature and additional data obtained by the authors. We tackled these questions using both conventional and phylogenetically based analyses. Our results show that lizards from the L. goetschi group and the genus Liolaemus in general vary in critical thermal minimum in relation to mean air temperature, and particularly the L. goetschi group shows that air temperature is associated with critical thermal range, as well as with body temperature. Although the effect of phylogeny cannot be ignored, our results indicate that these thermal biology aspects are modelled by cold environments of Patagonia, while other aspects (preferred body temperature and critical thermal maximum) are more conservative. We found evidence of co-evolutionary patterns between critical thermal minimum and preferred body temperature at both phylogenetic scales (the L. goetschi group and the extended sample of 68 Liolaemus species).
Oecologia, 2013
The importance of the thermal environment for ectotherms and its relationship with thermal physio... more The importance of the thermal environment for ectotherms and its relationship with thermal physiology and ecology is widely recognized. Several models have been proposed to explain the evolution of the thermal biology of ectotherms, but experimental studies have provided mixed support. Lizards from the Liolaemus goetschi group can be found along a wide latitudinal range across Argentina. The group is monophyletic and widely distributed, and therefore provides excellent opportunities to study the evolution of thermal biology. We studied thermal variables of 13 species of the L. goetschi group, in order to answer three questions. First, are aspects of the thermal biology of the L. goetschi group modelled by the environment or are they evolutionarily conservative? Second, have thermal characteristics of these animals co-evolved? And third, how do the patterns of co-evolution observed within the L. goetschi group compare to those in a taxonomically wider selection of species of Liolaemus?W e collected data on 13 focal species and used species information of Liolaemus lizards available in the literature and additional data obtained by the authors. We tackled these questions using both conventional and phylogenetically based analyses. Our results show that lizards from the L. goetschi group and the genus Liolaemus in general vary in critical thermal minimum in relation to mean air temperature, and particularly the L. goetschi group shows that air temperature is associated with critical thermal range, as well as with body temperature. Although the effect of phylogeny cannot be ignored, our results indicate that these thermal biology aspects are modelled by cold environments of Patagonia, while other aspects (preferred body temperature and critical thermal maximum) are more conservative. We found evidence of co-evolutionary patterns between critical thermal minimum and preferred body temperature at both phylogenetic scales (the L. goetschi group and the extended sample of 68 Liolaemus species).
Regional Environmental Change, 2014
Ectothermic organisms strongly depend on temperature, making them an excellent model to study the... more Ectothermic organisms strongly depend on temperature, making them an excellent model to study the impact of global climatic change (GCC). Under global warming, species may be forced to move toward colder environments, such as higher latitudes, higher elevations or both. However, several studies show that responses may vary significantly in different groups of species. Therefore, it is unclear whether species' current distribution range sizes will be affected in future climatic scenarios. In addition to the specific possible effect of range size changes, the potential consequences of distributional range shifts also should be considered. Here, our aim is to assess whether GCC may affect a group of Liolaemus lizard species based on their current geographic distribution range size and whether the effect is uniform across all species using species distribution models (SDMs). Our results show that range boundaries of the fourteen species switch toward higher altitude and latitude in future scenarios. Additionally, there is not a unique pattern in terms of increase or decrease in potential range for lizards in Patagonia in future scenarios. Finally, our results show that the original distribution range size is determinant for the resultant SDMs projections, suggesting that species with a high degree of endemicity may be susceptible to a greater impact of GCC.
Uploads
Papers by Débora L Moreno Azócar