Critical Connections

Illustration of bird migration paths

NPS Image


Conserving migratory species is one of the greatest challenges facing the NPS, particularly as human activities spread across areas used by migratory animals (Berger et al. 2010). Migratory birds nesting in NPS areas present unique conservation challenges because they are influenced by conditions and events in more than one part of the world, including along their migration routes and wintering areas that are often thousands of miles away from their protected breeding grounds. We launched our Critical Connections Program in 2014 to help expand our knowledge and understanding of the movements of Alaska’s migratory birds and identify the areas and resources they use throughout their lives. Contact Carol McIntyre with questions or to learn more about our program.

About Migratory Birds

Many of the birds that breed in Denali travel thousands of kilometers each year to return to their nesting areas. These are the true "globe trotters" of the bird world and they connect Denali to global ecosystems.

Many of the 21 species of shorebirds that breed in Denali are long-distance migrants. Shorebirds nesting at higher elevations include the American golden plover, upland sandpiper, surfbird, and Baird’s sandpiper. Shorebirds nesting at lower elevations include the semipalmated plover, greater and lesser yellowlegs, solitary sandpiper, wandering tattler, spotted sandpiper, whimbrel, least sandpiper, long-billed dowitcher, common snipe, and red-necked phalarope. Birds with intriguing names, like the wandering tattler, attract bird watchers by the score. The American golden plover has exquisite plumage, an evocative voice, and a globe-spanning reach (they winter in South America). Surfbirds, who spend most of their lives along coastal areas in the "surf", nest in the mountainous regions of Denali. George Wright made the first scientific observation of a surfbird nest on a rocky ridge in Denali on May 26, 1926.

Two elegant species, the long-tailed jaeger and the arctic tern grace the summer skies of Denali. The beautiful long-tailed jaeger nests on the tundra and these lithe aerial hunters patrol the northern landscape in search of prey. Their wintering areas are not well-documented, but they probably spent most of the winter at sea. Equally as agile and elegant as jaegers, arctic terns nest near the numerous lakes and ponds in Denali where they seem to hover effortlessly over the water in search of prey. The arctic tern is probably the most famous long distance avian migrant in the world, traveling between breeding grounds in the arctic and wintering habitat on the waters near Antarctica.

Several species of passerines are true globe trotters and these species attract much interest from bird watchers and scientists alike. Northern wheatears are summer visitors that nest in the tundra in Denali and spend their winters in sub-Saharan Africa. Arctic warblers commonly nest in willow thickets and their harsh calls are difficult to ignore. This Old World warbler winters in southeastern Asia (China, Indonesia, the Philippines, and Borneo) but returns to Denali and arctic regions to breed. (Adolph Murie, one of the first scientists to work in Denali, documented the first two nests of this species for North America among the tall willows of Igloo Creek in 1955.) Blackpoll warblers breed across the boreal regions of North America. This tiny bird is a celebrity in the migration world. Their annual journeys between North America and South America are among the longest of passerine birds.

Why Study Bird Migration Paths

  • Nearly 80 percent of bird species in Denali National Park are migratory. In spring, these birds arrive from locations around the world to nest and raise their young.
  • Scientists know that certain birds breed in one place and spend the winter in another place. However, little is known about the path between these locations.
  • Birds’ health is affected by conditions outside of Denali – specifically along their migration path and at wintering areas.
  • Studies show decreasing numbers of migratory birds. Death or injury during migration may be a major factor threatening populations.

Research in the Park

Park scientists work with the Denali Education Center and Alaska Geographic to run the Critical Connections Program. The Critical Connections Program aims to understand and communicate the year-round needs of Alaska’s migratory birds. Program researchers attach location devices to birds in Denali National Park. Upon retrieval, these devices help identify migration routes, wintering locations, and the effect environmental conditions have on bird survival. If you have questions about the program, please email Carol McIntyre, National Park Service wildlife biologist and project leader.


Further Reading

The Amazing Migratory Journeys of Blackpoll Warblers: Blackpoll Warblers make incredible migrations in autumn and spring. Blackpoll warbler movements from Denali were included in a range-wide study where scientists tracked individuals using tiny geolocator tracking devices. Blackpoll Warbler Migration.

Songbird Exposure to Mercury: Little is currently known about the level exposure to mercury encountered by migratory songbirds. While songbirds are more sensitive to mercury than other birds, high-latitude migrants have not been widely studied. This study looked at mercury exposure in 12 migratory songbirds breeding in Denali National Park and Preserve. Most species sampled showed low levels of mercury in their feathers, but some individual birds had high enough mercury concentrations that they may show physiological or behavioral impacts.Songbird Exposure to Mercury.

Arctic Animal Movement Archive: The Arctic Animal Movement Archive (AAMA) is a collection of studies in Movebank that contain animal movement and other animal-borne sensor data from the Arctic and Subarctic. As of November 2020, this collection includes 214 studies that contain over 43 million locations of over 12,000 animals recorded from 1988 to the present. Movebank is a global platform, and we recognize the Arctic as a region undergoing rapid climate and ecosystem changes that have impacts around the world. Animal movement data can tell us whether and how animals are responding to changes in the Arctic through altering their migrations and behaviors, and could provide remotely-sensed indicators of environmental conditions. We have developed the AAMA to strengthen efforts to archive, share and use Arctic-relevant data in Movebank to address urgent questions related to movement ecology, wildlife management and conservation, ecosystem monitoring and remote sensing in the Arctic. The AAMA also serves as a showcase for public and access-controlled data archiving that can meet data-sharing obligations for funding and publishing. Many studies are publicly available for exploration, and in all cases data owners can be contacted directly to discuss proposed uses.

Photo Galleries



This list of references will help you to learn to more about bird migration and studies of bird migration based in Alaska’s National Parks.

Berger, J., S. Cain, E. Cheng, P. Dratch, K. Ellison, J. Francis, . . . S. Zack. (2014).Optimism and Challenge for Science-Based Conservation of Migratory Species in and out of U.S. National Parks. Conservation Biology, 28(1), 4-12. Retrieved February 19, 2021.

Britten, M.W., C.L. McIntyre, and M. Kralovec. 1995. Satellite radiotelemetry and bird studies in national parks and preserves. Park Science 15:20-24.

Brown, J.L., B. Bedrosian, D.A. Bell, M.A. Braham, J. Cooper, R.H. Crandall, J. DiDonato, R. Domenech, A.E Duerr, T. E. Katzner, M. J. Lanzone, D.W. LaPlante, C.L. McIntyre, T.A. Miller, R.K. Murphy, A. Shreading, S.J. Slater, J.P. Smith, B.W. Smith, J.W. Watson and B. Woodbridge. 2017. Patterns of spatial distribution of golden eagles across North America: how do they fit into existing landscape-scale mapping patterns? Journal of Raptor Research 51: 197-215.

Davidson, S. C., G. Bohrer, E. Gurarie, S. LaPoint, P. J. Mahoney, ... K. Joly, ... J. P. Lawler, ...B. Mangipane, ... C. L. McIntyre, ... P. A. Owen, ... M. S. Sorum, ... et al. 2020. Ecological insights from three decades of animal movement tracking across a changing Arctic. Science 370(6517): 712-715.

DeLuca, W. V., B. K. Woodworth, S. A. Mackenzie, A. E. M. Newman, H. A. Cooke, L. M. Phillips, N. E. Freeman, A. O. Sutton, L. Tauzer, C. McIntyre, I. J. Stenhouse, S. Weidensaul, P. D. Taylor, and D. R. Norris. 2019. A boreal songbird’s 20,000 km migration across North America and the Atlantic Ocean. Ecology 00(00):e02651. 10.1002/ecy.2651

Jahn, A. E., S. B. Lerman, L. M. Phillips, T. B. Ryder, and E. J. Williams. 2019. First tracking of individual American robins (Turdus migratorius) across seasons. Wilson Journal of Ornithology 131(2): 356-359.

McIntyre, C.L., D.C. Douglas, and M.W. Collopy. 2008. Movements of Golden Eagles (Aquila chrysaetos) from interior Alaska during their first year of independence. Auk 125:214-224.

McIntyre, C.L., D.C. Douglas, and L.G. Adams. 2009. Movements of juvenile Gyrfalcons from western and interior Alaska following departure from their natal areas. Journal of Raptor Research 43:99-109.

McIntyre, C.L. and S.B. Lewis. 2016. Observations of migrating Golden Eagles in eastern interior Alaska offer insights on population size and migration monitoring. Journal of Raptor Research 50: 254-264.

McIntyre, C.L., and S.B. Lewis. 2017. Statewide movements of non-territorial Golden Eagles in Alaska during the breeding season: information for developing effective conservation plans. Alaska Park Science.

Phillips, L., and C. McIntyre. 2015. Critical Connections: Conserving Migratory Birds in Alaska’s National Parks. Alaska Park Science

Stenhouse, I. J., E. M. Adams, L. M. Phillips, S. Weidensaul, and C. L. McIntyre. 2019. A preliminary assessment of mercury in the feathers of migratory songbirds breeding in the North American subarctic. Ecotoxicology, DOI 10.1007/s10646-019-02105-2.

Last updated: February 25, 2021

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