Foraging & Microclimates
Changes in the earth’s climate are occurring nonlinearly through space and time. As an example, winters of the Northern Hemisphere are warming at an accelerated rate resulting in an attenuated winter season and a higher likelihood of extreme weather events (like cold snaps and early snowmelt). These changes are occurring against a backdrop of persistent land use changes. Understanding how populations and species will respond to changes in climate, weather, and land cover is a central goal of climate change ecology. Phenotypic flexibility — the ability of an organism to adapt to environmental changes — is key to understanding how species and populations will adapt to a changing climate.
The quandary of the “little bird in winter” has perplexed ecologists for years as birds must carefully balance the need to acquire enough energy to meet thermogenic demands while being exposed to predation during a time of year when resources are most limiting. We are using radio-frequency identification-enabled (RFID) bird feeders) to obtain information on the foraging behaviors of individual birds that have been fitted with Passive Integrated Transponders (PIT). By placing feeders in a diversity of woodlots spanning a fragmentation gradient, and collecting fine-scale temperature (microclimate) and habitat information, we are able to examine foraging in birds through space and time to determine what and how broad- and fine-scale environmental factors influence behavior and survival.
Recent related publications
Bonter, D.N., B. Zuckerberg, C. W. Sedgwick, W. M. Hochachka. 2013. A tradeoff between starvation and predation risks in bird foraging behavior? Proceedings of the Royal Society B | Biological Sciences 280: 20123087. Link
Latimer, C. and B. Zuckerberg. 2016. Forest fragmentation alters winter microclimates and microrefugia in human-modified landscapes. Ecography | DOI: 10.1111/ecog.02551. Link
Seeking Shelter in the Snow
For many winter-adapted animals, below-the-snow environments serve as important refugium from extreme winter temperatures. The effects of climate change, including less persistent snow cover and increasing thawing and refreezing events, will likely alter the winter landscape for many species. When snow conditions are favorable, Ruffed Grouse (Bonasa umbellus) and other gallinaceous birds often roost in burrows under the snow. When the snowpack is too shallow or dense, grouse roost in trees or on top of the snow. We are conducting a radio telemetry study exploring the ecological conditions that drive grouse winter roost site selection and the demographic consequences that may be associated with a warming winter environment. Grouse roosting outside of snow burrows may experience increased stress resulting from cold exposure or predation risk. Changes in forest cover influence winter microclimates, wind exposure, and snow accumulation and persistence. Consequently, we are also exploring how these landscape features may be associated with favorable snow burrowing conditions and snow burrow use by grouse.