Raptor View Research Institute: Research Projects, Osprey

Missoula is located along the Clark Fork River, just downstream from of one of the largest Superfund sites in the country. For more than 100 years, heavy-metal contaminants from mining operations at the Anaconda smelter have accumulated behind the Milltown Dam. These contaminants include mercury, arsenic, lead cadmium, zinc and copper. The removal process is already underway and there is legitimate concern that these heavy-metal contaminants could find their way into the watershed downstream. For more information on the Clark Fork remediation project, visit the Clark Fork Coalition.

As top predators that feed exclusively on fish, ospreys serve as biological indictors, i.e. “canaries in the coal mine” of the health of the aquatic ecosystems. By testing ospreys for contaminants and monitoring the health of local populations, we can gauge the level and extent of the contamination present in these ecosystems. RVRI’s osprey research project presents an ideal opportunity to establish baseline data for pre- and post-dam removal contaminant levels, as well as using ospreys as “bio-sentinels” for other Montana watersheds.

We are proud to be partnering with several local experts, University of Montana researchers Dr. Heiko Langner and Dr. Johnny Moore (Environmental Biogeochemistry Lab) and Dr. Erick Greene (Division of Biological Sciences and Wildlife Biology), to closely examine the causes, locations and possible effects of mining-related contaminants on ospreys and the ecosystems that support them. Preliminary findings from our research show that blood sampled from many ospreys along the Clark Fork River contain high concentrations of mercury and selenium.

During the 2007 field season we accessed 15 nests, tested and banded 28 nestlings, roughly doubling our sampling effort from 2006. This brings our two-year project total to nearly 23 nests and more than 43 nestlings. Preliminary results are troubling, with many of our nestlings showing mercury levels 100 times higher than what would be considered toxic in humans.

Baling Twine Project

Through monitoring, we have encountered a serious, rather unexpected hazard to area ospreys. Baling twine is a polypropylene rope used to tie bales of hay, and it often gets left in fields after ranchers open the bales to feed livestock. Ospreys apparently go to great lengths to collect baling twine and line their nests with it: We have found baling twine in nearly every nest located in our study area. This results in a big problem, since the chicks and even the adults can easily get tangled in it. In some areas it kills more than 10 percent of the chicks before they fledge, as well as some of the adults. An osprey nest that blew down in a wind storm last spring contained more than a quarter of a mile of baling twine!

We are excited to report that two students from Hellgate High School, Max Egenhoff and Matt Parker, are working diligently to remedy this problem. These two outstanding young men are working closely with Dr. Erick Greene and Anicka Kratina-Hathaway (an undergraduate biology student from The University of Montana) and have taken the lead on finding a solution to the osprey baling twine dilemma.

OSPREY PROJECT