Thursday, February 15, 2018

Gull Excitement at Hagerman NWR

Text and photos by Laurie Sheppard

In early spring, Hagerman National Wildlife Refuge attracts large numbers of gulls, as many preparing for migration join those that wintered here. Most are Ring-billed Gulls, but it’s worthwhile to look closely through the large flocks because frequently you will find a few Herring Gulls, Franklin’s Gulls, or other species migrating through. This week, though, we have had a very unusual visitor – a Glaucous Gull (Larus hyperboreus) has landed in our midst. Jack Chiles reports that this is the first time one has been seen at Hagerman NWR and many birders have rushed to the refuge to get that rare sighting.

Glaucous Gulls are very large, with some approaching 28 inches, compared to the Ring-billed Gulls’ mere 17-21 inches. The Glaucous Gulls’ typical wingspan is nearly five feet, which rivals that of the familiar Turkey Vulture, and the gulls can exhibit bursts of speed of up to 40 mph. They are said to be the second largest gull species, behind only the east coast’s Great Black-backed Gull. They are strikingly pale and have been described as “ghostly”. Adult Glaucous Gulls have a yellow bill and both adults and juveniles have dark pink legs and feet. In any group of gulls, the refuge’s visitor will appear much bigger and lighter than others nearby, particularly because of its white wing tips. Most other gull species found in north Texas have dark wing tips.

Note the differences in size and coloring between the larger Glaucous Gull and the smaller, more common Ring-billed Gull.
Glaucous Gulls breed in the Arctic, along marine and freshwater coasts, or on nearby tundra, cliffs, or ice edges. Both sexes build their nest which is little more than a shallow depression in a mound of grass, moss, twigs, and occasionally feathers with little or no lining. These might be at the water’s edge or in grassy areas atop cliffs, on the cliff’s ledges, or in the rocky scree at the base of the cliff. Both parents tend the eggs and care for the young until they become independent. It takes four years for a Glaucous Gull to fully reach maturity and their lifespan in the wild may be ten years or more.

Glaucous Gull shows its pale feathers and pink feet as it prepares to land.
 Like most gulls, Glaucous Gulls are omnivores with a varied diet. They will eat fish, berries, mollusks, small birds or mammals, eggs and chicks of other birds, and vegetation. They will also scavenge dead fish, carrion, and human refuse, and will attempt to steal food from other gulls and terns. They often forage while walking or swimming. The gull at the refuge has frequently been seen in the vicinity of other gulls, especially in the shallow water near Harris Creek or the exposed area off J Pad.

Glaucous Gull feeding on a dead fish.
During the winter, Glaucous Gulls migrate south along the coastal edges of the continent, but most adults remain north of Virginia in the east and California in the west. Occasionally, some birds migrate further south, but nearly all of those are immature Glaucous Gulls. This appears to be the case with the one seen on the refuge, which has the black-tipped bill and occasional brown freckling of a third winter bird. Migrating Glaucous Gulls are rarely found very far inland, which makes our visitor unusual.

Markings of an immature gull include the black-tipped pink bill bordered by brown feathers and slight brown freckling on the chest and wings.





1 comment:

  1. interesting; wonder if this bird will eventually find its way back to its own type or will remain with this crowd.

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