An expanding cityscape and its multi-scale effects on lizard distribution.

Area of Science:

• Urban ecology
• Ecology and conservation
• Wildlife biology

Background:

• Urbanization causes complex environmental shifts, impacting species selection pressures.
• Understanding how urbanization's scale, heterogeneity, and land-use change affect species persistence is crucial.
• The Peninsular rock agama (Psammophilus dorsalis) is studied in Bengaluru, India, to assess urbanization impacts.

Purpose of the Study:

• To evaluate how urbanization alters environmental conditions and influences the presence of Psammophilus dorsalis.
• To examine the relative importance of landscape and microhabitat factors in predicting lizard presence and abundance across an urbanization gradient.

Main Methods:

• Environmental factors (habitat composition, connectivity, land surface temperature [LST], artificial light at night [ALAN]) were derived from remote sensing and citizen science data.
• Urbanization was measured by distance from city center and proportion of built-up area.
• A multi-scale approach was used to predict lizard presence (landscape scale) and abundance (microhabitat scale).

Main Results:

• Habitat diversity and ALAN showed non-linear changes with urbanization.
• Lizard presence at the landscape scale was predicted by LST (positively correlated with cropland).
• At the microhabitat scale, Psammophilus dorsalis presence was associated with a higher proportion of rocks.

Conclusions:

• Urbanization creates environmental predictors that do not consistently vary across gradients.
• Many environmental factors do not appear to be strong selection pressures for this rock agama in the urban landscape.
• Quantifying urbanization across multiple axes and considering species-specific environmental factors at various scales is vital for understanding species persistence.