July 7, 2018
Salish Sea, Pacific Northwest
The official name for these gulls is Heermann’s, and there is little reason anyone in the Salish Sea would use their historical name since we rarely see them in their white-headed breeding colors. There’s a very narrow window for us here and it’s — right now. They are already shifting into the mottled grey we see for most of the time these remarkable gulls are up this way.
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They breed down in the Sea of Cortez over a short period in the spring and depart immediately northward to spend the rest of the year feeding along the west coast. We only see them hereabouts until the end of October; they take a more leisurely path back to Baja on their southward migration.
White-headed, or Heermann’s, gulls are unusual in several ways. They —
—> are the only North American gull that is grey-bodied
—> have a bright orange bill
—> breed almost exclusively on one small island in the Sea of Cortez
—> migrate northward for the summer
—> live only along the ocean shores and out to sea
Because of their narrow niche, they are vulnerable to sudden environmental changes and local human activities. Heermann’s gulls enjoyed a resurgence in population after their nesting island was protected from egg-collectors in the 1960s, but other anthropogenic threats make their continued survival problematic.
IUCN Red-list
This species is considered Near Threatened as it has a highly restricted breeding range, with 90% of the world population breeding on a single small island. Nesting populations fluctuate widely in response to climatic events, although these fluctuations are less than one order of magnitude. It is likely to be at high risk from catastrophic events or local anthropogenic changes,
In the last eight years, almost total breeding failure has occurred in five nesting seasons. This is mainly due to environmental anomalies, that result in lack of food availability and, secondarily to overfishing of small pelagic fish (mainly Pacific sardine) their main food sources.
It’s always a relief for me to see them again each July. The juveniles won’t arrive for another month or two, if at all. In recent years juveniles have been rare, around here anyway.
Not many pics to share today, with the few gulls mostly parked out on Whale Rocks:
I counted about 40 there on the Rocks, with a few on the water. Checking eBird, I note reports have been coming in across the northern Salish Sea for the past few days. The first wave has arrived for the summer.
It is wonderful to see them in their breeding colors glory, however briefly. A 19th c bird illustration book describes them beautifully —
This bird can usually be spotted on shore or out at sea, and is rarely ever seen inland. It has a distinct appearance from other gulls, with its most most eye-catching feature being the pearly white head of the breeding plumage, which contrasts luminously against the dusky gray body and black wings.
John Cassin (1813-1869)
Plate 05, The White-headed Gull
From: Illustrations of the Birds of California, Texas, Oregon, British and Russian America
Philadelphia: J.B. Lippincott & Co., 1856
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