COS 124-4 - Climates Extremes and Changes in Vegetation Together Drive Habitat Use and Movement

Background/Question/Methods

Climate change is predicted to increase the intensity and frequency of climate extremes, impacting the survival and population dynamics of species. Because movement is a fundamental characteristic of life, understanding how animals move across the landscape is critical to their conservation. Some animals use specific vegetation types to mitigate extreme heat and move differently in response to climate variability. Thus, linking how vegetation and climate extremes alter how animals use habitat and move across the landscape will be important for understanding how changes on the landscape influence their resiliency to climate change. Non-migratory species are predicted to be more negatively impacted by climate extremes because they require predictable resources.

We used a non-migratory species, the Northern Bobwhite (Colinus virginianus; hereafter bobwhite) as a model to study how a non-migratory animal uses habitat and moves through the landscape in response to climate extremes. We collected global positioning system data on bobwhite across western Oklahoma during 2019–2020 and paired these data with meteorological and vegetation data to analyze habitat use and movement using a generalized linear-mixed modeling approach. We analyzed movement by calculating three different movement metrics from an individual’s 12-hour path: cumulative distance, net displacement, sinuosity.

Results/Conclusions

We found that bobwhite used denser tree cover and higher normalized difference vegetation index (NDVI) values during hotter conditions. During windy conditions bobwhite used denser shrub cover as air temperature increased; however, during calmer conditions, bobwhite used denser shrub cover when air temperature < 30 C^o occurred. Regarding movement, the interaction between vegetation and climate influenced bobwhite movement. Bobwhite in areas with higher NDVI variance moved farther when mean air temperatures were >0^oC than bobwhite in areas with low NDVI variance. When mean air temperatures were < 0^oC, NDVI variance had little effect on the cumulative distance of bobwhite.

Our study determined that the interaction between vegetation and climate extremes drives habitat use and movement. Our findings show that non-migratory species such as bobwhite will likely require denser woody cover to survive increased climate extremes in the future, potentially creating a conservation paradox given the ongoing concerns regarding the impacts of increased woody encroachment on the conservation of North American grasslands. Further, conservation plans aimed at helping mitigate the effects of climate change on species should consider managing for heterogeneity to make species resilient to climate extremes, especially during high heat events.