Browsing by Author "Buckley, Emma E."

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    Community- and species-level responses of reptiles to an avian ecosystem engineer
    (John Wiley and Sons Inc, 2025) Buckley, Emma E.; Maritz, Bryan
    Ecosystem engineers can alter the distribution and abundance of resources in a landscape, thereby impacting the distribution of other species that use those resources. Although reptiles are known to respond to the ecosystem engineering of birds, case studies are surprisingly rare. Here, we sampled reptile abundance and diversity underneath pairs of trees that do, or do not, contain the thatched colonies of sociable weavers (Philetairus socius) in the Kalahari. We conducted our systematic sampling both when the weavers were breeding, and again at the beginning of summer before the onset of breeding. We test the hypotheses that (1) reptile species richness and (2) overall abundance are higher under trees with weaver colonies, and whether differences in those measures vary with season. We additionally explicitly test whether colony trees hosted greater abundances of (3) Kalahari tree skinks (Trachylepis spilogaster), and (4) cape thick-toed geckos (Pachydactylus capensis)—the two most frequently detected species in our study. We find robust support for all four hypotheses. Trees with colonies had approximately twice the richness of trees without colonies when weavers were breeding but showed no difference in richness outside of the breeding period. Trees with colonies also yielded approximately twice the number of captures (from all reptile species) than did trees without colonies, but this effect was present in both seasons. We found strong support for trees with colonies hosting larger populations of Kalahari tree skinks than noncolony trees in both seasons. We also found strong support for cape thick-toed geckos occurring at higher abundances under colony trees. Taken together, our results indicate that multiple species of reptiles are responding to the presence of sociable weaver colonies in the Kalahari, and that those species effects are summing up to detectable community-wide effects.
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    Patterned, plain, and in-between: An assessment of ecogeographic divergence between colour pattern morphs of the common egg-eater Dasypeltis scabra
    (Taylor and Francis Ltd., 2024) Barends, Jody M; Bassier, Ielhaam; Buckley, Emma E.
    Intraspecific variation in colour patterns may reflect adaptive responses to local environmental regimes that favour selection of different trade-offs between visual communication, thermoregulation, and anti-predatory functions. Understanding the drivers of colour pattern variation within species can therefore provide valuable insights about adaptation. However, the ecogeographic correlates, and thus the ecological drivers, associated with the segregation of different colour morphs for most reptile species, including snakes, are not well known. Here, we examined differences in environmental niches associated with occurrence records of preserved museum specimens and georeferenced photographic images of common egg-eaters (Dasypeltis scabra) to characterise ecogeographic divergence between typically patterned, patternless, and faintly marked individuals. We gathered 1707 records that we assigned as either patterned, plain, or intermediate morphs. Most records were of patterned individuals, which were widely distributed in southern Africa. Climate niches differed between morphs as plain and intermediate snakes were restricted to high-elevation areas in the highveld grasslands of South Africa, and woodland-dominated areas in the central and eastern parts of both Zambia and Zimbabwe, but there were no areas where only plain or intermediate snakes occurred in isolation from patterned snakes. Environmental niche modelling predicted minimal areas suitable for co-habitation of colour morphs. We speculate that plain or weakly-marked colour patterns likely developed as an adaptation to increase camouflage ability in open areas in grassland and certain woodland habitats.