Critter Corner No. 30 – The Hudsonian Godwit by George Sly

The assemblage of bird species which make Goose Pond FWA their home, either permanently or seasonally, is remarkable. There are secretive rails, stealthy grassland sparrows, impressive numbers of migratory waterfowl, raptors such as owls and hawks, and a menagerie of passerines. And let’s not forget the bird that inspired the Friends’ annual Marsh Madness Festival, the sandhill crane. The Cornell Lab of Ornithology’s eBird.org site reports that 287 different kinds of birds have visited Goose Pond FWA since its establishment. Doubtless there is a bird species or bird family here that every outdoor enthusiast could claim as their favorite.

Among the wealth of avian residents at Goose Pond, one group, the shorebirds, often goes unnoticed—except by diehard birders. Their notoriously tricky identification can frustrate casual observers but overlooking them is a missed opportunity. The sandpipers, plovers, and phalaropes passing through on their fall and spring migrations carry some of the most astounding stories of bird migration imaginable. Just as importantly, their journey underscores the international significance of Goose Pond FWA’s restored wetlands.

One such bird is the Hudsonian godwit. This large (15 in.) representative of the sandpiper clan has been described thusly: a graceful shorebird with long, slightly upturned bills, long legs, and a glorious breeding plumage of gold, brown, and brick red.

During the summer, this species inhabits the wet tundra meadows, bogs, and tidal mudflats of northern Canada as well as southern and western Alaska. Using their long beak to probe in the mud, they feed on invertebrates such as larval insects, snails, clams, small crustaceans, and marine worms. The tip of their bill is flexible, allowing them to gasp such prey deep in the mud or even at the surface.

In June or July, Hudsonian godwits leave their self-sufficient young and begin one of the avian world’s longest migrations – a trip from the North American Arctic to the southern tip of South America some 10 000 miles away. Their southward route involves non-stop flights of great distance. Satellite data has revealed that some birds fly from the Mackenzie River Delta of Alaska to the southern Hudson Bay area without stopping. This flight takes two to three days and covers some 1,500 to 2,000 miles. Here they rest and forage for a few weeks in preparation for the next leg of their journey.

Leaving Canada, Hudsonian godwits head southeast, continue out over the western Atlantic, and then turn southward. During this leg of their trip, they make a nearly 4000-mile, nonstop flight (lasting five days) to the Orinoco River basin of Venezuela. Others may land in Columbia. From here they move southward at a more leisurely pace to their final destination in southern Argentina or even southern Chile. They arrive in August or September, springtime in the southern hemisphere.

One is left amazed when considering the ability of these birds to accomplish migratory trips of such immense distances. How do they do it? The implications for metabolic demands, navigation at night over vast stretches of water, and shear endurance are staggering.

Like other avian migrants, they use the sun and stars for navigation. They also utilize their ability to detect the earth’s magnetic field to orient themselves. Another strategy that may help during long migrations is known as unihemispheric slow-wave sleep. Utilized in some other bird species and certain marine mammals, this type of sleep relies upon one hemisphere of the brain being in deep sleep while the other half is active. This allows the migrants to rest while remaining alert to navigation cues and other outside sensory inputs.

In 2011/2012, Hudsonian godwits began showing up at Goose Pond FWA. This typically occurs in the fall because their return trip from South America in the spring follows a different, more westerly route (and may involve a non-stop flight of 6,000 miles.)

Some have hypothesized that the godwits passing through GPFWA are coming from Alaska. Do they fly directly here? Do they travel to southern Hudson Bay first? Data on godwits migrating inland are not abundant. Their tendency to linger here suggests that GPFWA isn’t just a quick stop but is acting as a staging area before the final push to South America.

Regardless of whether they make additional stops in the southern U.S. or head southeast to begin their ocean transit to South America, one thing is clear: Goose Pond FWA is of great importance in ensuring that these international travelers have a safe place to rest, feed, and thus fortify themselves before continuing upon one of the animal kingdom’s most astonishing migratory journeys.