Birds of Denali Park

Birds from all over the world come to breed and nest here as in the circumpolar north.  Birds such as the Long-tailed jaegers from the south Pacific, Northern Wheatears from Africa, Asiatic birds and Arctic warblers and Arctic Terns from as far south as Antarctica come here for three reasons.

• To take advantage of 24 hours of daylight so they can feed around the clock and get their young fledged and ready for migrations of thousands of miles.
• Because of adequate, undisturbed nesting habitats and reduced competition, many of the migratory and resident birds of Denali spend their winters in dense flocks of the same or even mixed species but when they are in their breeding grounds in summer they are very territorial and need lost of space to spread out for breeding and nesting.  Denali’s wilderness and much of the circumpolar north provide this undisturbed space.
• Protein.  Even if these birds spend their winter in the tropics feeding on fruit, they need a high protein diet to raise their fledglings and we’ve got it big time in the form of mosquitoes.  Our peak insect abundance is at the time when most of the chicks hatch and is also in synch with our peak daylight hours, which is also in synch with our biggest floral bloom, which is also in synch with our most abundant hatching of the pollinators, which includes mosquitoes.  It is all tied together and driven by the sun.  If something gets out of synch, say there is a very late snow storm (and it can snow any month of the year here) and plants get delayed in producing flowers, or temperatures have not been warm enough for insects to hatch, everything get impacted.  Mosquitoes are a vivid example of this interdependence.  There are al least 30 known species of mosquitoes in Alaska and at least 13 species in Denali.  Each species of mosquitoes requires a certain number of hours above a certain temperature to hatch.  Usually by solstice, our longest day, we have had those temperatures, but if not, everything gets impacted including blueberries which gets pollinated by mosquitoes and there goes bear food.

Not only do these long distance migrators need healthy wintering grounds and healthy breeding and nesting grounds, what really underpins the success of their migrations are the several important staging areas they use in route.  Some of these birds literally travel thousands of miles and consume over half their total body weight to get there.  They are highly dependent on certain, predictable stopover sights to refuel.  The most important staging area in Alaska, particularly for shorebirds is the Copper River Delta.

Target Species List

The target list of 40 species of conservation concern in Denali was developed using contemporary information on each species group or individual species.  General conservation issues are summarized in Table 1 and briefly explained below.

1. Waterbirds including swans, ducks, and grebes are of conservation concern for many reasons.  Trumpeter Swans, although increasing in population size and distribution in Alaska, are vulnerable to habitat change (i.e., drying wetlands) and environmental contaminants on their wintering grounds.  Several species of diving ducks, including all three species of Scoters, exhibit population declines, perhaps due to change in breeding habitat.  Horned Grebe and Red-necked Grebe both exhibit change in distribution and perhaps population size. PLEASE NOTE:   Although Scaup are routinely observed during the summer in DNP, it is important to document their presence as both Lesser and Greater Scaup are exhibiting significant population declines across their range.
2. White-tailed and Rock Ptarmigan are of conservation concern due to their specific habitat requirements during the nesting season, and the likelihood that this habitat will change as a result of global warming.
3. Gyrfalcons are of conservation concern due to their specific habitat requirements and their low nesting densities.
4. Shorebirds are of particular conservation concern, owing to their long migrations, slow reproductive rate, and dependence on a wide variety of wetland habitats for which extensive losses have occurred (Myers et al. 1987, Bildstein et al. 1991, Brown et al. 2001, Donaldson et al. 2001).  Evidence accumulated during the past 10-15 years has suggested that many shorebird populations may be declining in North America and Europe (Browne et al. 12996, Austin et al. 2000), and perhaps worldwide (Wetlands International 2002, Stroud 2003).  In North America, Several species are exhibiting population declines including Lesser Yellowlegs and Solitary Sandpiper.
5. Long-tailed Jaegers are of conservation concern due to their specific habitat requirements and their low nesting densities.
6. Short-eared Owls are of conservation concern due to their low nesting densities and their significant population decline across most areas of North America.  This is a species in serious decline over much of its range.  Breeding Bird Survey data show a statically significant 3.5% per year decline from 1966-2001 across the overall range and an even steeper decline of 11.4% per year in Canada.  In northeastern U.S. the species was listed as threatened in 7 states as of 1993.  It is on the National WatchList of the National Audubon Society.
7. Several species of passerines are of conservation concern due to population declines and their rapid response to changes in their habitats.

Images courtesy of Kirsty Knittel