Biological Sciences Faculty Publications

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The drive for animals to regulate their water content can have significant consequences for food webs in xeric ecosystems. But the importance of animal water balance (gains vs losses) for mesic food webs has not been explored. Impervious surfaces in cities absorb and re-radiate solar radiation, raising local temperatures. Higher temperatures lead to greater rates of organismal water loss. Thus, urbanization of mesic regions may lead to greater likelihood of desiccation, with consequences for food webs. We tested the effects of animal water balance on a mesic urban food web by supplementing animal-available water (but not plant) within trees in a parking lot in Raleigh, NC, a mesic city with previously documented urban warming. We found that during dry periods, arthropods in control trees were desiccated (lower water content), with higher water demand behavior. This coincided with shifts in community composition during dry periods. Continuous experimental supplementation of animal-available water mostly reduced or erased these patterns. Thus, animal water balance may play a role in mediating food web dynamics in mesic cities.

Publisher's Statement

VC The Author(s) 2018. Published by Oxford University Press. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact

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Publication Title

Journal of Urban Ecology





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