The Marbled Murrelet, a common seabird on the Oregon Coast, already suffers from loss of nesting habitat, and is now facing a new threat to its survival, says an article by published by Oregon Live on Tuesday.
Murrelets, related to common murres and puffins, have been fighting for habitat space for years, according to the article. They require old-growth forests to nest and lay eggs, and due to the loss of those forests, in the early 1990s the birds were given threatened status under the Endangered Species Act.
Unfortunately, loss of nesting habitat isn’t their only concern now, according to a recent study from Oregon State University. Warming ocean waters are causing a decrease in the bird’s normal food supply – Krill and Forage Fish such as smelt, anchovies, herring, and capelin. The study’s lead author and researcher in the College of Forestry, Matt Betts, told Oregon Live that the journey from ocean to nesting grounds, located as many as 60 miles from the coast, requires the birds to get the proper amount of food.
“Given that these prey items tend to be in lower abundance when ocean temperatures are high, changing climate conditions could reduce prey availability as well as the tendency for Murrelets to nest in the future,” Betts explained.
The co-author on the study, Jim Rivers, adds that the nesting patterns of Murrelets are rare. “There’s no other bird that feeds in the ocean and commutes such long distances inland to nest sites, that’s really unusual.”
The nesting sites of the Murrelets are in danger too, says Oregon Live. “As more forests in the Pacific Northwest have been subject to logging and wildfires, like the ones that have ravaged Oregon during the past several weeks,” author Kale Williams writes, “suitable habitat for the birds has been shrinking.” Intended to preserve old-growth forests, the Northwest Forest Plan was passed 25 years ago, but in spite of that plan, old-growth forests are still in decline in some places.
Researchers confirmed that Marbled Murrelet populations were down four percent per year in Washington between the years of 2000 and 2017. Increases in birds were seen in at-sea surveys in Oregon however. It turns out that ocean conditions can affect the numbers of birds who actually seek to nest each year.
Rivers told Oregon Live, “Murrelets might be missing from inland sites not because the forest is unsuitable for nesting, but because they have inadequate forage fish during the summer breeding season. That means it is critical that we consider factors that influence both marine food resources and terrestrial nesting habitat when considering how to recover Murrelet populations.”
The bird’s status under state regulations has been under debate in the last few years. In February 2018, the state wildlife commission moved the Marbled Murrelet from threatened to endangered, but reversed that decision a few month later. A judge ruled that the retraction was illegal because there was no written basis for the denial provided by the commission. The commission was ordered to hear evidence again for a change in the birds’ status. That meeting will take place in November.