(Photos courtesy Kersti Muul)
Some WSB readers have asked about the status of the Caspian Terns – those prehistoric-sounding, angle-winged seabirds heard passing overhead in the past, when they nested on a roof along the Duwamish River – where a heat wave had catastrophic effects in 2021. Then they lost that nesting site entirely. West Seattle-based wildlife biologist Kersti Muul has continued to research and monitor them. Attention is now on a colony in north Puget Sound that is being ravaged by yet another problem. Kersti tells us:
It brings me great sadness to report that a fragment colony (more than 1,000) of nesting Caspian terns on Rat Island (Port Townsend) is being decimated by avian influenza (HPAI) and hundreds have died already. WDFW has collected over 800 adult carcasses so far and and over 150 chicks.
The nesting colony I’ve been researching since 2018 didn’t really materialize here this year; about 100 or so showed up in April and I spent the following months trying to locate them.
Their historical nest site was demolished in January and the Coast Guard had USDA put deterrents up where they attempted to nest last year. They weren’t in any other alternate sites. I went out with the Port of Seattle last month and went up river to investigate derelict barges also, but no nesting.
I had wondered if the colony got hit with HPAI in migration areas and just didn’t come back in the big numbers (colony was 4000+).
There are some nesting currently on Rat Island and somehow bird flu popped up with a vengeance. The area is closed and being closely monitored by WDFW. So far we have not had any positive pinniped cases, but has happened elsewhere in the world at these kinds of preserves where they share close spaces with nesting seabirds. It may be a matter of time. Three deceased seal pups were tested, but they continue to be negative, and no eagles yet either. They will be doing another body collection and count early next week. There are some oystercatchers nesting there as well and still have not been infected. That may change when WDFW assesses nest week.
This is the 3rd year in a row that has been catastrophic for the terns. As you remember, 2021 heat killed a lot of babies (over 200). 2022 total nesting failure, as they were flushed from nesting site and nested late. I hypothesize that embryonic development was corrupted by heat. 2023 local HPAI outbreak, and colony is being wiped out during nesting…. This colony fragment had become the largest and most important in the region. Last September I collected fish bones from the Coast Guard roof for diet analysis by NOAA Fisheries.
I spoke with Steve Hampton yesterday, Kitsap Audubon Conservation Chair, and now a docent at Fort Flagler, for the specific situation. He says adults are still coming in with food, which means there are still chicks to feed. They are nesting in a swale but it is impossible to see them from there.
It is likely that some of this colony is part of the colony that nested at T-106, and the Coast Guard roof respectively. The colony this year there is the biggest it has ever been. But we are still missing 3000+/- birds.
Rat Island also had an almost complete nesting failure last year as the colony was completely flushed on the 4th of July at low tide by human harassment, and then again in August when they attempted to nest again, via coyote predation on chicks. There were around 500 adults nesting and only 10 chicks were successful unfortunately after the second, very late attempt.
Rat Island remains closed and WDFW requests people refrain from going to the area. As you know, HPAI is highly infectious and can be moved to new areas on shoes and clothing, and dogs can be infected by inhaling viral particles of infected birds or carcasses.
(Tern babies at Terminal 106 in better times)
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