Seabird Die-Offs

Explanation: While hiking a winter beach in southern Oregon along the Pacific U.S. Coast in November of 2023, I encountered a series of seabirds that had perished and washed ashore. My discoveries included a Rhinoceros Auklet and several Western Grebes, photos presented here, as well as several Herring Gulls, all in one local stretch on one beach.

Occasional deaths of seabirds is not a new phenomenon. But recent years have seen unusual accounts of multiple incidents along Alaska, western Canada, Washington, Oregon and elsewhere. There was a massive die-off in 2016 in the Salish Sea between Washington and British Columbia, Canada, and along Alaska, affecting multiple seabird species including those listed here as well as Tufted Puffins, Common Murres, Cassin's Auklets, and others. It is thought that the die-offs occurred because of major heat waves causing ocean warming and associated loss of marine foods.

One account (see: Learn 2022, cited below) suggests that hundreds of Rhinoceros Auklets that had washed up in the 2016 event were food-starved (emaciated) and had died from some major bacterial infection, perhaps aggravated by ocean warming events.

And another major source of seabird die-offs seems to be avian influenza ("bird flu") that has now appeared from pole to pole, including in the Salish Sea.

A Western Grebe that had succumbed to
some local or regional event at sea in late 2023,
possibly yet to be determined.

I could not determine the specific cause of the demise of the birds I discovered, but I reported the finding to the Oregon Department of Fish and Wildlife who asks for any such sightings.

Information:
Learn, J.R. 2022. A wave of die-offs. The Wildlife Professional 16(4):16-24.
Wagner, E.L., S.F. Pearson, T.P. Good, P.J. Hodum, E.R. Buhle, and M.B. Schrimpf. 2023. Resilience to a severe marine heatwave at two Pacific seabird colonies. Marine Ecology Progress Series HEATav4. https://doi.org/10.3354/meps14222.

EPOW - Ecology Picture of the Week