Lizard community structure and spatial resource use along a forest-savannah-urban habitat gradient in the Dahomey Gap (West Africa)

The city and its urban biome provides an extreme laboratory for studying fundamental biological questions and developing best practices for sustaining biodiverse and well-functioning ecological communities within anthropogenic built environments. We propose by studying urban organisms, urban biotic communities, the urban biome, and the interactions between the urban biome and peri-urban built and natural environments, we can (1) discover new "rules of life" for the structure, function, interaction, and evolution of organisms; (2) use these discoveries to understand how novel emerging biotic communities affect and are affected by anthropogenic environmental changes in climate and other environmental factors; and (3) apply what we have learned to engage residents of the urban biome, and design cities that are more biologically diverse, are provided with more and better ecosystem services, and are more equitable and healthier places to live. The built environment of the urban biome is a place that reflects history, economics, technology, governance, culture, and values of the human residents; research on and applications of the rules of life in the urban biome can be used by all residents in making choices about the design of the cities where they live. Because inhabitants are directly invested in the environmental quality of their neighborhoods, research conducted in and about the urban environment provides a great opportunity to engage wide and diverse communities of people. Given the opportunity to engage a broad constituency-from basic researchers to teachers, civil engineers, landscape planners, and concerned citizens-studying the translation of the rules of life onto the urban environment will result in an integrative and cross-cutting set of questions and hypotheses, and will foster a dialog among citizens about the focus of urban biome research and its application toward making more equitable, healthy, livable, sustainable, and biodiverse cities.

Discovering and Applying the Urban Rules of Life to Design Sustainable and Healthy Cities

Under the influence of light: How light pollution disrupts personality and metabolism in hermit crabs.


 Studies on habitat gradients are particularly interesting for the community ecology theory, but almost no investigation has been carried out on community structure of any vertebrate groups along gradients of habitat that were modified by humans in historical or prehistorical times, such as for instance the Dahomey Gap in West Africa. Here, we analyze the community structure of lizards in suburban Lomé (Togo) and in comparison with nearby savannah and forest sites, with a suite of statistical methods. Overall, we recorded 25 lizard species, with a heavy reduction in species richness from forest (18 taxa) to savannah (13) and suburbs (9). 24% of the species occurred in all habitat types, 40% exclusively in forest, and only two were exclusive of suburban habitats. Suburban habitat types were relatively homogeneous in terms of number of observed species (maximum number of taxa per habitat = 6). There were significant interspecific differences in both substratum type preferences and vertical spatial niche by species, but with no evidence of a nonrandom niche partitioning pattern, and hence with a competitively assembled community structure. There was a nonrandom “clustered” distribution of the various species along the available resource categories, thus indicating that species-specific preferences instead of community-driven mechanisms are more likely to explain the observed patterns. We concluded that lizard communities in tropical cities are (i) less species-rich than in the surrounding more natural habitats, (ii) usually clustered into specific habitat/substratum types (often artificial ones), and (iii) not assembled through competitive interactions.

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The City in the Tropics: Lizard Community Structure and Spatial Resource Use Along an Habitat Gradient of the Dahomey Gap (West Africa)

Most species of lizard are either diurnal or nocturnal, and it is extremely rare to find species that operate both diurnally and nocturnally, or that may shift from diurnality to partial nocturnali...

Nwaiwu Urubia

Papers

From diurnal to nocturnal activity: a case study of night-light niche expansion in Agama agama lizards