This research is being primarily conducted by Jeff M. Martin for his doctoral dissertation work. There are four primary themes: fossils, heat stress, nutritional isotopes, and implications.
He uses the fossil record to describe a trend in body size change in response to climate change. He then uses thermal imaging technology to measure heat stress, cold stress, heat load, and body size in modern bison throughout the Great Plains from Saskatchewan to Texas. Later, he will use stable isotopes to describe food change along a temperature gradient of the Great Plains. Lastly, he will combine the results from above into conservation policies and commercial management protocols to help ranchers, managers, and stewards adapt to these changing animals in response to climate change.
He uses the fossil record to describe a trend in body size change in response to climate change. He then uses thermal imaging technology to measure heat stress, cold stress, heat load, and body size in modern bison throughout the Great Plains from Saskatchewan to Texas. Later, he will use stable isotopes to describe food change along a temperature gradient of the Great Plains. Lastly, he will combine the results from above into conservation policies and commercial management protocols to help ranchers, managers, and stewards adapt to these changing animals in response to climate change.
1. Fossil Record - The Past is the Key to the Present
Based on the data we have, bison are incredibly variable through time and respond very quickly to abrupt climatic shifts, sometimes within a generation or two. They have done so numerous times in the past during extreme high and low temperatures. To show this, we have prepared a walk-through of the data, click here or click on Current Research, Fossil Record tabs.
2. Thermal Imaging - Cutting Edge Technology for Measuring Heat Stress
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Heat stress is detrimental to mammals at most stages of their lives. Particularly, during growth, it may be a cause of smaller body size. I am visiting about 15 bison locations (National Parks, State Parks, and Ranches) to document bison heat loads under summer and winter conditions. To learn more, click here or click on Current Research, Thermal Imaging.
Thermal image of a mature female bison facing into the sun with wind at her back. Notice the white, yellow, and red areas are warm, whereas the greenish-blue and blue areas are cool. J.M.Martin, 2017.
3. Nutritional Isotopes - Food Quality and Quantity Change over Time
Plants absorb minerals and elements from the atmosphere and ground. They grow in certain climates that support their needs. Particularly, Carbon and Nitrogen are of interest for plant energy and protein. As bison eat these plants, the bison absorb these same elements from the plant and are deposited in their tissues (bones, teeth, hair, meat, and organs alike). I will be sampling bison tissues from various harvested bison at meat processing plants to analyze differences in absorbed nutrient quality and quantity. To learn more, click here or click on Current Research, Isotopes.
4. Implications - What does it all mean?
The above is all very cool work. Combined, they will shed light on the mechanisms controlling bison body size as it relates to climate. Once the primary mechanism is figured out, I will ask to work with folks to help develop plans and protocols to help conservationists and producers adapt and mitigate with future climate change impacts on bison. To learn more, click here or click Current Research, Implications.
A table of references can be found here.