Osprey

An osprey comes in for a landing next to its mate on their nest.
Ospreys come to Yellowstone in the summer to fish and raise their young.

NPS/Jim Peaco

 

Like many other birds of prey, osprey (Pandion haliaeetus) populations declined due to pesticide use in the mid-1900s. Populations rebounded during the latter part of the 1900s. The first study of osprey in Yellowstone National Park occurred in 1917 by M. P. Skinner, the park’s first naturalist. It was not until 1987 that the Yellowstone National Park bird program began monitoring breeding osprey annually, although an extensive survey on reproduction, diet, and habitat was conducted during the 1970s.

Since monitoring began, Yellowstone’s population of osprey has been considered relatively stable. On average, 50% of nests succeed (produce young) each year, with each successful nest producing an average of one to two young.

Ospreys are surveyed via fixed-wing aircraft and by ground-based surveys from May through August. During the survey flights, the majority of nests are monitored for occupancy and breeding activity. In addition, all suitable lakes and rivers are surveyed for potential new territories and nest sites.

 

Number in Yellowstone

  • In 2016, 29 active nests were monitored, with 69% of them successful, higher than the 30-year average (51%).
  • 33 young were produced. Productivity for active nests in 2016 (1.14 young per nesting female) was greater than the 30-year average (0.82).
  • None of the 3 osprey nests at Yellowstone Lake were successful in 2016.

Identification

  • Slightly smaller than the bald eagle.
  • Mostly white belly, white head with dark streak through eye.
  • Narrow wings, dark patch at bend.
  • Fledglings have light edges to each dark feather on their backs and upper wing surfaces, which gives them a speckled appearance.

Habitat

  • Usually near lakes (such as Yellowstone Lake), river valleys (such as Hayden, Madison, Firehole, and Lamar valleys), and in river canyons (such as the Gardner Canyon and the Grand Canyon of the Yellowstone River).

Behavior

  • Generally returns to Yellowstone in April and leaves in September.
  • Builds nest of sticks in large trees or on pinnacles close to water.
  • Lays 2–3 eggs in May to June.
  • Eggs hatch in 4–5 weeks.
 

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 nesting success at Yellowstone Lake.

 
Bald eagle standing over a fish that it's eating.

Bald Eagle

Bald eagles can be seen along Yellowstone's many rivers and lakes.

A peregrine falcon perched on a branch.

Peregrine Falcon

Peregrine falcons are some of the fastest birds.

A pair of white pelicans floating on water.

Colonial Nesting Birds

Colonial nesting birds—pelicans, gulls, and cormorants—primarily nest on the Molly Islands.

A loon swimming on a lake.

Common Loon

Loons in Yellowstone are some of the southern most breeding populations.

A pair of swans swimming on a lake.

Trumpeter Swan

Trumpeter swans are the largest wild waterfowl in North America.

A white-breasted bird with gray and black wings and black beak on a mound of snow

Songbirds and Woodpeckers

Passerine and near passerine species comprise the majority of bird species in Yellowstone.

A small, gray bird perched on a rock along a stream holding an insect in its beak.

American Dipper

Also known as the water ouzel, these birds dive into water for aquatic insects.

Profile of a raven's head and chest

Raven

Ravens are smart birds, able to put together cause and effect.

A sandhill crane walking through a marshy landscape.

Sandhill Crane

Sandhill cranes nest in Yellowstone during the summer.

A yellow-breasted bird with black markings calls out as it stands on a stick

Birds

About 150 species build their nests and fledge their young in Yellowstone.

An eared grebe near Mammoth Hot Springs

Sound Library

Immerse yourself in the aural splendor of Yellowstone.

 

Resources

Annual Bird Program Reports. National Park Service, Yellowstone National Park. https://www.nps.gov/yell/learn/nature/birdreports.htm

Baril, L.M., D.W. Smith, T. Drummer, and T.M. Koel. 2013. Implications of cutthroat trout declines for breeding opsreys and bald eagles at Yellowstone Lake. Journal of Raptor Research 47(3): 234–245.

Poole, A.F., R.O. Bierregaard, and M.S. Martell. Osprey. The Birds of North America Online. https://birdsna.org/Species-Account/bna/species/osprey/introduction

Last updated: June 16, 2017

Contact the Park

Mailing Address:

P.O. Box 168
Yellowstone National Park, WY 82190-0168

Phone:

(307) 344-7381

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