In May 2023 COASST received an unusual set of reports from one of our partners. (With photos included. That’s our favorite kind!)
The incoming news was about a group of species not often discussed by our marine science program. Land birds – more specifically passerines, or perching birds – had washed up on Oregon beaches in large numbers.
In this excellent photo (credit: Joe Metzler. We can see you’re a COASSTer at heart!) birds are sorted by species and condition, which made identification a breeze for dead bird verifier Charlie Wright. We noted Western Tanager, Black-headed Grosbeak, Wilson’s Warblers, and Warbling Vireo, among others.
This type of report is uncommon enough that we jumped into action. We sent out a call to COASSters in the area near the reports (thank you for your replies!) and dove into our data to see if we could find anything like this event in a previous year.
Here’s what we discovered:
From our long-term dataset, we know that at this time of year (April-May) Oregon COASSTers usually only report 0.00586 land birds per km of beach. That translates to 5 carcasses every 1000 km of surveyed beach (approximately 620 miles)! In other words, beached perching birds aren’t too common this time of year.
We also found that Oregon COASSTers have conducted over 10,000 beach surveys in the last 23 years! But in all that time, only 48 surveys recorded perching birds (mostly crows), and the highest count of land birds on single survey was only 4 birds.
We confirmed our suspicions – this was an unprecedented event!
There was one other astonishing piece of news associated with the beached land birds. Beachwalkers reported PILES of insects in the wrackline along this same stretch of coast.
Look closely (if you dare!) at the photo to the right, and you’ll see ladybugs, flying ants, beetles, and more! The presence of these insects helps us figure out the mystery of the land birds.
While we aren’t sure exactly what happened, we have a strong suspicion. Strong east-winds were recorded the weekend of May 14th, which likely blew flying birds and insects alike out to sea. When they died close to shore, they were quickly washed back in and deposited on the local beaches.
Initially we were not sure that any COASSTers had captured this event in our dataset, but we are proud to say that our survey team at Roads End South came through! They recorded the first Oregon COASST report with SIX perching birds just a few days later. The COASST survey methods worked!
Thanks to Jay Withgott, Dave Lauten, Kathleen A. Castelein, Joe Metzler and the Oregon Birding Association for reaching out with wreck news and filling in the gaps in our story.