Understanding how changes in weather alter the movements of northern bobwhite (Colinus virginianus)

Landon Neumann, Samuel D. Fuhlendorf, Craig A. Davis, Kent Andersson, R. Dwayne Elmore and Laura E Goodman, Natural Resource Ecology and Management, Oklahoma State University, Stillwater, OK

Background/Question/Methods
Climate is one of the primary drivers of animal behavior. Even though climate and weather are intertwined they are different. Little is known how direct changes in different climate parameters influence animal movement, especially in smaller animals (< 14 kg) because of technology constraints. Animal movement can directly impact survival and the spatial arrangement of individuals across landscapes. As climate change continues to alter weather and biodiversity, it is important we understand how approximate changes in weather affect animal movement. The Northern Bobwhite (Colinus virginianus) is a small declining North American galliform that experiences a variety of weather extremes throughout its lifetime. We utilized the recent advancement in GPS technology to better understand how direct changes in weather influence their movements.
During 2019-2020, we fitted Northern Bobwhite with GPS transmitters at four Wildlife Management Areas (WMA) in western Oklahoma. We obtained hourly weather data from five Mesonet stations located near the WMAs and paired the data with the appropriate movement data. To quantify movement, we calculated two movement metrics, hourly movement and sinuosity and analyzed the data using a linear and generalized linear-mixed modeling approach. We used an a priori AIC method to investigate the top models.
Results/Conclusions
We analyzed 43,940 hourly movements and 9982 3-hour paths. Mean hourly movement was 50.6 m, while mean sinuosity for a 3-hour path was 0.50. For both movement metrics, the top model was the two-way interaction of air temperature and solar radiation and the two-way interaction of wind speed and solar radiation. At low solar radiation, we found that mean hourly movement increased as air temperature increased. However, at medium and high solar radiation mean hourly movement increased as air temperature increased until 27oC when it plateaued and then decreased. At medium solar radiation, mean hourly movement decreased as wind speed increased. We found that at low solar radiation mean sinuosity decreased as air temperature increased, while at medium solar radiation mean sinuosity increased as air temperature increased.
Our study showed that Northern Bobwhite change their movements in response to direct changes in weather. We detected thresholds where Northern Bobwhite movement increased but then decreased. These threshold points suggest that physiological limitations may be created when certain weather parameters become extreme. As climate change continues, altering weather, an understanding of how direct changes in weather influence animal movement will be vital to developing conservation strategies to moderate the impacts of climate change on animals.