Paper Reviewed
Martin, R.O., Cunningham, S.J. and Hockey, P.A.R. 2015. Elevated temperatures drive fine-scale patterns of habitat use in a savanna bird community. Ostrich 86: 127-135.

Noting that a future warming of the world could present new thermoregulatory challenges that may be particularly acute for animals living in already hot and arid environments, Martin et al. (2015) report that many animals already use thermally-buffered microsites to avoid temperature extremes, as reported by Wolf et al. (1996), Hetem et al. (2012) and Briscoe et al. (2014). And they thus suggest that these animals "may be able to reduce their exposure to the direct impacts of rising temperatures," citing the confirmatory findings of Williams et al. (2008), Kearney et al. (2009) and Scheffers et al. (2013).

Determined to learn for themselves, however, the three South African researchers proceeded to investigate patterns of tree use by birds in the southern Kalahari Desert across different times of day and days of varying maximum air temperature. And what did this investigation reveal?

Martin et al. report that "on 'hot' days (<35°C) birds showed increased preference for trees that provided the greatest density of shade (Boscia albitrunca)," and they say that "this effect was particularly pronounced at the hottest times of day," both of which findings led them to conclude that "these trees may be critical thermal refuges for birds," especially, it might be added, if the Earth were to begin to warm again after the nearly two decades of thermal stasis it has recently experienced.

References
Briscoe, N.J., Handasyde, K.A., Griffiths, S.R., Porter, W.P., Krockenberger, A. and Kearney, M.R. 2014. Tree-hugging koalas demonstrate a novel thermoregulatory mechanism for arboreal mammals. Biology Letters 10: 20140235.

Hetem, R.S., Strauss, W.M., Fick, L.G., Maloney, S.K., Meyer, L.C.R., Shobrak, M., Fuller, A. and Mitchell, D. 2012. Activity re-assignment and microclimate selection of free-living Arabian oryx: responses that could minimize the effects of climate change on homeostasis? Zoology 115: 411-416.

Kearney, M., Shine, R. and Porter, W. 2009. The potential for behavioral thermoregulation to buffer 'cold-blooded' animals against climate warming. Proceedings of the National Academy of Sciences USA 106: 3835-3840.

Scheffers, B.R., Edwards, D.P., Diesmos, A., Williams, S.E. and Evans, T.A. 2013. Microhabitats reduce animal's exposure to climate extremes. Global Change Biology 20: 495-503.

Williams, S.E., Shoo, L.P., Isaac, J.L.., Hoffmann, A.A. and Langham, G. 2008. Towards an integrated framework for assessing the vulnerability of species to climate change. PLoS Biology 6: 2621-2626.

Wolf, B. and Walsberg, G. 1996. Thermal effects of radiation and wind on a small bird and implications for microsite selection. Ecology 77: 2228-2236.