Three separate prongs of research by Rocky Mountain College undergraduates are assisting osprey populations this year along the Yellowstone River. One effort has already resulted in a published paper with an RMC junior as lead author.
Ospreys are summer native “fish eagles” who eat the rich fish of the Yellowstone River while they raise chicks. About 45 nesting pairs live along the middle Yellowstone River. They winter as far as South America, and most return yearly, but face hazards from people’s activities. The studies use ospreys as biological indicators of ecological integrity of the Yellowstone River.
Renee Seacor (’16) of Ossining, N.Y., had her paper on baling twine entanglements of osprey nests published in the February Canadian Naturalist. Polypropylene twine used to wrap Montana hay bales persists through years of weather and rot. It is soft and shows up in abundance to cushion eggs in osprey nests. In three seasons, RMC Assistant Professor Kayhan Ostovar’s team found five of 178 banded fledglings entangled in nest baling twine.
Three were cut free and survived, one died, and one was euthanized. Seacor wrote, “Vigilance by citizen scientist nest monitors and assistance from power companies are the only short-term solutions to reducing mortality … from entanglement.”
Efforts to educate the public to reduce twine on the landscape will help ranchers and wool producers as well as nesting ospreys, Ostovar said, since twine hazards also negatively affect the humans’ livelihoods.
Matt DeWit (’15) of Billings is studying population distributions and nesting successes of ospreys in the Yellowstone valley. Working with citizen volunteers from Yellowstone Valley Audubon Society, DeWit has tracked active and abandoned nesting sites of osprey along the Yellowstone from Gardiner to Miles City. He has mapped more than 80 nests this season.
Conducting intensive observations of randomly selected nests, DeWit can determine the food intake of individual chicks by measuring the size and type of fish that parents carry. He will then work to look for correlations in the parents’ nesting success with the chicks’ diet, distance from the fish source, water clarity, and other variables. DeWit is finding the middle Yellowstone to be a sweet spot for osprey success, possibly related to a greater diversity of fish species, abundance of nesting structures, and water clarity.
Linnea Warlick (’15) of Warren, N.J., hopes to attend veterinary school and aspires to do wildlife veterinary work professionally. Warlick works with the osprey team and Professor Marco Restani of St. Cloud State University, who helps Yellowstone River Research Center (YRRC) to take tiny blood samples from fledglings to check heavy metal loads in their blood. Since ospreys are at the top of the aquatic food chain (as are humans), they can bioaccumulate toxins and heavy metals.
After a field season of making blood slides and learning how to band and handle wild birds of prey, Warlick will look for correlations between heavy metals such as mercury or lead and the white blood cell counts on her slides. Her research is blazing potential new techniques for evaluating wildlife health.
All three student projects, managed by Ostovar, have received professional and fiscal support from the Yellowstone River Research Center and the SEED (Science Education Enhancement and Development) program at RMC, a USGS grant from the Montana Water Center, Royal Bank of Canada, Cinnabar Foundation, Yellowstone Valley Audubon Society, and many local power companies who help researchers access nests.