Update: Michelle McDowell, a biologist with the U.S. Fish and Wildlife Service, emailed me today. She says that Bird Research Northwest just completed an aerial survey and noticed possible new colonies. Here is an excerpt from their website:
Aerial survey of the Salish Sea; main objective of flight was to identify active Caspian tern and double-crested cormorant colonies in the area; confirmed or suspected nest sites for terns include: Sea-Pac warehouse rooftop in Seattle (ca. 300 adults and 125 attended nest), NW Industries warehouse rooftop in Seattle (ca. 150 adults and 20 attended nests), Rat Island (ca. 220 adults and 50 attended nests), Dungeness Spit (115 adults, a few sitting), Smith Island (ca. 220 adults and 35 attended nests), and Bellingham waterfront warehouse rooftop (ca. 120 adults, a few sitting).
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Remember the Caspian terns? They’re the noisy birds that look like pointy gulls and often hang out in large numbers on the Everett waterfront.
A couple weeks ago, a few readers emailed wondering what had happened to them. The terns really like to hang out near the former Kimberly-Clark site. When the mill closed operations, the terns use the warehouse roof to lay eggs and raise their young.
This year, the terns showed up in April and, in their usual noisy way, made their presence known. Then, around the end off May, they vanished rather than hanging around to nest and raise young.
I contacted Ruth Milner, Washington Department of Fish and Wildlife biologist, to see if she had any idea why the birds had moved on. She visited the waterfront last week and didn’t see or hear any terns, either.
She said the U.S. Fish and Wildlife Service told her earlier in the spring that the property owners would not deter the terns from using the roof, but were trying to deter them from the gravel area.
Milner says her best guess is that the terns have decided the area is not suitable for nesting for some reason and have moved on to a better site.
“On my first visit to the site in April, there were 5 bald eagles circling the area,” Milner wrote in an email. “They apparently were, like me, making a check to see if the terns were back. It’s possible that once the birds returned, the eagles harassed them to the point where they felt unsafe for nesting. Caspian terns are known for occupying a site for a while, but then moving on. When I was there on May 5th, there were terns at the site, many of them coming in with fish, but no sign of nesting. If the site no longer felt safe, but no investment in nesting had begun, it’s likely they have moved to a different site and will nest elsewhere this year.”
So, that’s what I know about the terns for now. If I get any more information, I’ll be sure to share it.