From Alaska

Marbled Godwit (Limosa fedoa)

The godwit in the video captures first what looks like a small crab, and later some kind of worm. These successful hits came after numerous plunges into the mud resulting in nothing. The birds have sensors in their beaks that allow them to feel what’s down there.

This species of bird, like the Long-billed Curlew I posted on the 13th, is only a part-time shorebird. It builds its nest and raises its chicks in the grasslands of the “Prairie Pothole Region” — the Dakotas, Montana, Alberta, Saskatchewan, Manitoba, and surroundings. That, at least, is the most numerous population. There are also smaller breeding sites on the Alaska Peninsula and in James Bay in northeastern Canada. Scientists have attached GPS trackers to a few birds to establish migration routes. Birds from the mid-continent area mostly spent the winters in Mexico.

Marbled Godwit on nest near Ugashik, Alaska. Source: Wikimedia. Photo Daniel Ruthrauff, USGS, Alaska Science Center

The birds we see here very probably came from the Alaska site and are of the Limosa fedoa beringiae subspecies. They nest onshore and inland in grasses with sedges and willows, in very thinly populated territory. Wikipedia has a photo of a godwit on a nest (right) near Ugashik, Alaska, a village with 12 inhabitants on the Alaska Peninsula. Another photo in the same area by the same photographer shows a godwit walking in grasses about as high as its neck.

On the birds’ migration they cross the Gulf of Alaska. Not counting possible rest stops along the northern coast, the direct distance from there to here is about 2,100 miles. A map based on GPS units attached to the birds indicates that many flew directly to California across the northern Pacific. but tended to follow the coast and make numerous rest stops on the migration back north.

As is also true of the curlew, female Marbled Godwits are a bit bigger and have longer beaks than males. Two of the birds I photographed this morning probably illustrate the difference. The top photo is, I think, a male. The other I believe is the female; her beak is noticeably longer.

Marbled Godwit (Limosa fedoa), probably male
Marbled Godwit (Limosa fedoa), probably female, based on longer bill

Scientists doing a study of more than 500 godwits captured the birds, drew a blood sample to establish gender, and measured the length of the upper crest of the bill (the culmen). Males measured less than 106 mm; females longer than 108 mm. The researchers established that in more than 95 percent of the cases the length of the culmen would correctly identify the sex of the bird. I don’t know why it was necessary to capture, draw blood from, and measure that many birds to establish this point.

Like the curlew, the godwit is threatened by loss of habitat.

Overall, the greatest threat facing Marbled Godwits on the mid-continental breeding grounds is loss and fragmentation of native grasslands and wetlands. At major mid-continental migration stopover sites, the principal threat is inadequate rights to, and/or availability of, water. This problem is further exacerbated by drought (G. Beyersbergen and H. Hands, pers. comm.). At coastal stopovers and in the winter range, Marbled Godwits face a host of major threats, principally residential development, industrial and petroleum contaminants, mariculture, and human disturbance, all of which contribute to habitat loss and degradation.

Read more: Conservation Plan Ayala-Perez Biogeography ADW Tracking Audubon Cornell Alaska Status

Similar Posts:

Leave a Reply

Your email address will not be published. Required fields are marked *

Translate »