• A bull elk bugles in Yellowstone National Park

    Yellowstone

    National Park ID,MT,WY

There are park alerts in effect.
hide Alerts »
  • Craig Pass Closed for the Season; Mammoth to Norris Closed Sept. 14-30

    The road linking West Thumb and Old Faithful is closed for the season—traffic should detour through West Thumb, Lake, and Canyon. The road from Mammoth to Norris is closed for two weeks—traffic should detour over Dunraven Pass. More »

Osprey Information Continued

Osprey sitting on large nest of sticks.

This osprey in its nest on a rock outcropping.

NPS/Bowersock

Identification
Osprey are slightly smaller than the bald eagle. They have a mostly white belly, a white head with dark streak through eye. Their wings are narrow, with a dark patch at the bend. These fish-eating raptors live near lakes (such as Yellowstone Lake), river valleys, and in river canyons such as the Gardner Canyon and the Grand Canyon of the Yellowstone River. In early spring, Osprey pairs build nests of sticks in large trees or on stone pinnacles close to water. The female lays 2–3 eggs in May to June and the eggs will hatch in 4–5 weeks. Fledglings have light edges to each dark feather on their backs and upper wing surfaces, which gives them a speckled appearance. Osprey migrants generally return to Yellowstone in April and leave in September.

Research
A recently completed study conducted by park biologists found a significant relationship between the declines in cutthroat trout and osprey reproduction at Yellowstone Lake. Recent increases in the number of young cutthroat trout caught by the Yellowstone fisheries program during the fall netting assessment are encouraging. An increase in cutthroat trout production may lead to an increase in nesting pairs of ospreys and improved nest success at Yellowstone Lake.

Did You Know?

Bison in Yellowstone.

There are more people hurt by bison than by bears each year in Yellowstone. Park regulations state that visitors must stay at least 25 yards away from bison or elk and 100 yards away from bears.