Ecological interrelationships in the Desert under Climate change
Empirical (on the right panel) and modeling (on the left panel; edited figure from: Lovelace et al. 2020) approaches that were used to examine the interactions between different microhabitats and their ectothermic users in general and under climate change and habitat loss.
Welcome to the Extreme Side of the Earth
The Judean Desert in the Dead Sea Region
When deserts become too extreme, animals can have difficulty coping with the rapid and intense changes in their environment
The two pictures above (Pseudotrapelus aqabensis on the left and Mesalina bahaeldini on the right) show thermal images of my study species which I examine in my lab.
Ph.D. Publications
Micro-habitats shape body condition of desert lizards
In extreme environments such as the Judean Desert, access to shading elements (more vegetation than rocks) near the lizards greatly improved their body condition in both summer and winter. The contribution of rocks and vegetation goes beyond just thermal benefits, as they provide other ecologically important services in both seasons. The positive synergistic effect of vegetation and rocks on lizard body condition (see figure below) suggests that their functions are complementary rather than overlapping. It is possible that vegetation plays an indirect rather than direct role by mediating food availability, while rocks play a more direct role by providing protection from adverse temperatures and predators. While such complementary interactions have rarely been studied and observed in nature, here I provide evidence that by focusing on only one type of microhabitat, we can inadvertently underestimate the importance of others. Thus, in order to enhance and improve conservation efforts or make sustainable habitat changes in a given area, we should develop a better understanding of the effects of the natural microclimate in that area.
Figure: Higher availability of vegetation and rock cover synergically improves lizards’ body condition. The figure presents the significant interaction found in our statistical model between scaled mass index and the vegetation and rock cover. Under low vegetation cover, the positive impact of rock cover is much lower than under high vegetation cover. Similarly, higher rock cover substantially strengthens the positive impact of vegetation cover. Colours represent the predicted Scaled Mass Index of lizards.
Species need microhabitat diversity to survive under climate change and habitat loss
As biodiversity faces significant threats from habitat loss and climate change, we developed a biophysical modeling framework to study their impact on a desert lizard's activity and microhabitat selection. We predict that lizards will be active in open habitat during winter, but rocks are critical for their summer activity. Under climate change, however, warmer winters will necessitate bushes and small rocks for shade, while summers will become too warm for activity regardless of habitat loss. Our findings underscore the importance of seemingly insignificant microhabitats in future climates and emphasize the need for models that integrate microhabitat diversity and climate change for effective conservation.
Check out our paper in the media: Click Here
Seeking shelter from the extreme heat
Environmental temperatures are increasing worldwide, threatening desert ectotherms already living at their thermal limits. Organisms with flexible thermoregulatory behaviour may be able to mitigate the effects of extreme temperatures by moving among microhabitats, yet little work has tracked movement patterns of desert ectotherms in the wild over diurnal scales or compared behaviour among seasons. Here, we used camera traps to track the thermoregulatory behaviour and microhabitat choices of 30 desert lizards (Messalina bahaldini) in custom, outdoor arenas that provided access to open, rock, and bush microhabitats. We found that in the summer, lizards preferred to move to the shaded microhabitats and remain there under warmer
conditions. During winter, however, lizards’ activity was not related to temperature, and lizards mostly chose to remain in the open habitat. Interestingly, in both seasons, lizards tended to remain in their current microhabitat and moved infrequently between certain combinations of microhabitats. Our study shows that thermoregulation (shade-seeking behaviour) is a major factor during summer, helping lizards to avoid extreme temperatures, but not winter, and shows a novel effect of current microhabitat on movement, suggesting that other biotic or abiotic factors may also drive microhabitat choice. Understanding the complex factors at play in microhabitat choice is critical for developing conservation programs that effectively mitigate the
negative impacts of climate change on desert animals
conditions. During winter, however, lizards’ activity was not related to temperature, and lizards mostly chose to remain in the open habitat. Interestingly, in both seasons, lizards tended to remain in their current microhabitat and moved infrequently between certain combinations of microhabitats. Our study shows that thermoregulation (shade-seeking behaviour) is a major factor during summer, helping lizards to avoid extreme temperatures, but not winter, and shows a novel effect of current microhabitat on movement, suggesting that other biotic or abiotic factors may also drive microhabitat choice. Understanding the complex factors at play in microhabitat choice is critical for developing conservation programs that effectively mitigate the
negative impacts of climate change on desert animals
Figure: A lizard’s choice of microhabitat was determined by its current microhabitat in both seasons,
and by ground temperature in summer. Here, green and red arrows represent a high or low probability of
movement between microhabitats, respectively. Gradient-coloured arrows represent a positive (blue to
red gradient) and negative (red to blue) effect of temperature on movement, respectively. U-shaped arrows
represent probabilities of remaining in the same microhabitat. Numbers near solid arrows represent
the probability of movement between microhabitats. Numbers near gradient-coloured arrows represent
the change in the odds of movement per ◦C increase in temperature