Tuesday, May 22, 2012

Increasing seabirds in Gulf of Alaska and decreasing in Southern California?

An interesting article appears on the Marine Ecology Progress Series in the article: Phenology of pelagic seabird abundance relative to marine climate change in the Alaska Gyre by Thompson SA, Sydeman WJ, Santora JA, Morgan KH, Crawford W, Burrows MT (2012).

Part of the abstract states:
Overall, 5 species showed no change, 1 declined, and 9 species as well as all species combined showed increasing abundance. By season, 3 species increased in winter, 7 in late spring, and 6 in late summer. Eight of 15 species showed relationships with our environmental index. Increases in seasonal seabird abundance may be related to lengthening of the ‘growing season’, as demonstrated by temporal temperature shifts and expansion of peak chlorophyll concentrations. Seabirds of the Alaska Gyre are probably responding to changes in forage nekton that are related to this extended growing season by shifting their migration to later dates.
The full text appears in a pdf link. This is one study of several that may point to a redistribution of seabirds (abundance and diversity). It appears there is a trend for fewer seabirds in the Southern California Bight and more birds for a longer portion of the year in the SE Gulf of Alaska.

Saturday, May 12, 2012

Oregon pelagic birds: Horned Puffin

pelagic birds

On our May 5th trip we found a Horned Puffin, one of Oregon's rarer pelagic birds, 28 miles off Newport. The bird we found is my photo above. How rare is it? We've run almost 150 pelagic trips since 1994 and this was only the 5th time we've spotted this bird. That's about 3.3%

The Handbook of Oregon Birds (2009) by Herlyn and Contreras has this to say: "Rare to sometimes abundant visitor to the offshore waters of the [northeast] Pacific.... occasionally seen onshore in winter and spring." So, far offshore larger numbers of birds may occur in certain years. But the birds generally occur farther offshore than most traditional pelagic trips, and at seasons where there are fewer pelagic trips scheduled. You might say that the bird itself might not be all that rare in Oregon's offshore waters, but it is rarely seen.

However, also occasionally, a Horned Puffin will be found in summer amid breeding Tufted Puffins on the Oregon coast, but they do not breed in Oregon. So if you wait long enough, and do lots of seawatches, you will possibly see one of these birds from shore in Oregon.

Here, then, are the details of our sightings on our boat tours:
  • April 4, 1998, on a 20-hour trip where we got on the boat at night and were 60 miles offshore from Depoe Bay at dawn, we encountered 2 birds.
  • March 27, 2007 we encountered 7 live and 2 dead Horned Puffins 15-33 miles offshore from Newport. This followed unprecedented numbers of dead puffins (150+) washing up on Oregon's beaches during the winter/spring.
  • August 16, 2008 there was a bird just off the jetties at Newport.
  • February 21, 2009 a couple of people spotted a bird flying away from the boat about 8 miles offshore.
  • May 5, 2012 one bird 28 miles offshore from Newport.
So it is possible to see Horned Puffins on winter or spring pelagic trips from Oregon, especially if the trips travel well beyond 30 miles from shore. But it's not very likely. This species remains one of Oregon's rarer pelagic birds.