RVRI Research Update 03-27-13

RVRI Research Update 03-27-13

March 29, 2013

Adam Shreading and Rob Domenench share a research update about golden eagle, and osprey, tracking.

Five of the six adult Golden Eagles outfitted with GPS satellite transmitters on the MPG Ranch are well on their way towards their summer ranges.

This adult male spent his second winter entirely in the Bitterroot Valley, with the exception of a long loop through Idaho.

This adult female’s wintering movements were very similar to that of last year, including a trip east of the Continental Divide in mid-February.

We were beginning to think he would reside there, when he headed back west along the Clark Fork and I-90. He passed Missoula and, like 110270, went up the Ninemile Valley, continuing north into Canada. Currently he is in north British Columbia and still moving north. So far both he and 110270 have followed nearly identical routes through British Columbia along the Rocky Mountain Trench. We were surprised when this adult male left the Bitterroot Valley less than a week after capture, and spent more than a month between Anaconda and Butte.

The healthy eye shows the marbled, uniquely patterned iris indicative of an older Golden Eagle

This adult male has done several laps from the Bitterroot Valley out to the foothills of the Front Range west of Conrad, Montana.

This photo shows the transmitter as it was when located. Despite having the accuracy of a handheld GPS unit, the transmitter’s small size and the ruggedness of the area made it extremely difficult to find.

We expect the adult MPG Ranch Osprey to make a northern move for the ranch any day now. Currently, each Osprey is still on their wintering territories. We are checking on them daily and will put out an immediate update when they leave.

This adult male from the Ranch Entrance Nest is still sticking tight to his winter territory along the Bay of California on mainland Mexico. He appears to be doing well, fishing the mangrove islands and coastal estuaries.

The adult female from the Ranch Entrance Nest is still on her wintering ground along the Pacific coast of Nicaragua. We expect the females to stay on wintering territories a little longer than the males, who generally return first and secure the nest sites.

The adult male from the North Center Pivot Nest is along the Gulf Coast and coastal plain of Mexico. He spends all of his time near a small inland lake, bordered by a small aircraft runway. He is approximately 30 miles from the Caribbean Coast, 200 miles north of Veracruz, near the small farming village of Santa Rosa.