Wednesday, July 16, 2008

Rhinoceros Auklets - On the Decline?


Rhinoceros auklets, named for the horn-like growth on their beaks during the breeding season, are one of the most common sea birds in the San Juan Islands. We often see them bobbing in front of the lighthouse before sunset, small silvery fish dangling out of its beak. The rhinoceros auklet (affectionately called "rhinos") is able to hold multiple fish in its beak and still dive for more by using its spiny tongue to press the fish to the roof of its mouth. The above photo of an auklet was taken last October, but you can still see where the "horn" would be on its beak while in its breeding plumage.

While I've seen some auklets this summer on whale-watching trips, it seemed like they were much less plentiful than usual, so I posed to the question to my fellow naturalist Captain Pete to see what he thought. We often ponder wonders of the natural world together, but he hadn't personally noted anything different in the auklet population. Still, his curiosity piqued, he put in a phone call to a few of his friends to see what they thought.

One of the caretakers of Yellow Island Preserve does some informal surveys of seabirds flying by early in the morning. On a recent morning, he counted 700, which he felt was low, but he didn't have any historical counts at hand. Additionally, the leader of the marbled murrelet population survey team said on a recent count they counted 1000 auklets, compared to 2000 last year.

Hopefully its just a natural fluctuation in the population, and not part of the climate change related sea bird declines that have been prevalent in the Pacific Northwest over the past several years. Now that a few people around the islands have been alerted to my casual observation, maybe those doing bird surveys will take a closer look. I'll post an update if I hear any more updated data.

2 comments:

  1. Some of the recent literature (albeit 4 years old) doesn't rate population decline for the rhino auklet as of great concern. However, taking a look at populations further south, like at Point Reyes, there is a concern about the breeding population (difficult to see the date of that article). Cool picture of the rhino, BTW.

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  2. It always amazes me how things we do not expect are somehow linked to each other. Take this article that talks about rhino auklets being one of the most frequent species to perish in sockeye gill nets in Puget Sound. Since Sockeye numbers are now up (and presumably fishing for them is up) then that might be a reason that rhino auklet numbers are down?

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