Across Northern California, on beaches from Monterey to Point Reyes, malnourished seabirds have been appearing in alarming numbers, some shrunken to little more than feather and bone.
The sea-loving common murres, whose black or brown wing feathers and white bellies get them mistaken for penguins, are rarely seen alighting on beaches when healthy. Many of the thin-billed species are being brought into the International Bird Rescue Center in Fairfield, which says it is taking in the birds at the highest rates in 18 years.
The murres’ presence is significant to scientists because they’re considered a marker species, whose movements and numbers signal changes in the ocean’s food supply.
Six freshwater tanks at the bird rescue center are being used to nurse 140 common murres back to health. Typically the center only uses one or two tanks this time of year for stressed seabirds. Within the last month, more than 250 common murres have been brought into the center, which usually sees around 10 birds each month in late summer and early fall, said spokesman Russ Curtis.
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“We have seen murres covered in oil come in in large numbers over the years, but not this amount,” said Curtis. “These birds are not oiled – they’re just down to feather and bone.”
“They need a lot of calories and they need to grow,” he said. “The birds we are seeing do not even have flight feathers yet. Our gut tells us there is something going on in the marine environment.”
It’s not yet known why so many more birds are appearing, but scientists say warmer El Niño conditions in the Pacific Ocean may be to blame.
Warmer sea temperatures off the West Coast – up to 10 degrees warmer in some southern regions – are not likely to abate anytime soon, said Nate Mantua, research scientist with the National Oceanographic and Atmospheric Administration.
“Marine life is going to be really stressed for at least another six or seven months along the Pacific coast,” said Mantua.
Kyra Mills-Parker, deputy director for the Oiled Wildlife Care Network at UC Davis, said the slackening of trade winds, which is an effect of El Niño, decreases nutrient flow into the upper layers of the ocean. As a result, the birds must dive deeper to catch food, she said.
“An adult murre can dive up to as much as 590 feet, but young murres don’t have that ability and require fish to be at shallower depths,” Mills-Parker said.
Some of the birds that are being brought into the center are showing symptoms of catastrophic molting, where large patches of their bodies are missing feathers, said Kelly Berry, wildlife manager with the center. The cause is unknown, Berry said.
“This does not allow birds to behave normally, and that is when they get out of the water,” she said.
Many of the birds found on the beaches are young, but observers are now seeing adult murres suffering on area beaches.
During late summer, adults replace flight feathers all at once and become flightless for about a month.
“If the food is too deep or too far away, they can’t find enough food to survive, and they can’t fly out of the area,” said Hannah Nevins, seabird program director with the American Bird Conservancy. “Yesterday I was at Moss Landing State Beach and saw at least 50 dead murres in a stretch of 200 yards. This is an unusually high level of deposition.”
Edward Ortiz: 916-321-1071, @edwardortiz