Showing posts with label brandt's cormorant. Show all posts
Showing posts with label brandt's cormorant. Show all posts
Saturday, February 20, 2010
Feeding Frenzy!
The west side of the island seems to have two levels of bird activity: dead and absolutely teeming. Of late, it's been rare to observe more than a few dozen birds fishing off the west side of the island, but a bit earlier in the year we saw some very epic feeding frenzies.
In the above video from the first of February, we see innumerable western gulls, western grebes, brandt's and double-crested cormorants competing for their share of a fish run. Brown pelicans could be seen plunge diving among them.
click on the image for a larger size
The next day, there were still countless birds fishing between Alcatraz and the Golden Gate Bridge. Nearly all were cormorants.
click on the image for a larger size
The ways of the bay are mysterious indeed.
Wednesday, February 10, 2010
Tomb of the Cormorants!
Warning: This post contains graphic, though not gory, images of dead birds.
During the adventure upon which we discovered the falcon with her kill, we also explored the remnants of the cormorant colony. For our readers who aren't aware, by 2008, Brandt's Cormorants were the most populous nesting bird on Alcatraz, with 1700 nesting pairs reported in 2007, and 1500 in 2008. Then last year, in 2009, they began washing up dead by the hundreds around the bay and by the end of the nesting season, not a single pair bred on the island.
While the lack of nesting was pretty disturbing to us bird nerds out there on the rock, the full on carnage we found in the colony area was surely a result of the successful nesting colonies of years prior. Life is brutal, and bird life is certainly no exception. So put on your favorite gothy-metal album (I recommend some Fields of the Nephilim) and ponder the very nature of your existence as we present the horrors that were found in the......TOMB OF THE CORMORANTS!
Labels:
brandt's cormorant,
breeding,
brutal,
dead things,
gallery,
seasonal resident,
TOTALLY RAD
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1 comments
Friday, January 29, 2010
Island's western gull males remind desirious females that Valentine's Day is a ways off
Thinking I might have the opportunity to document some early mating, I recorded this female, the smaller gull on the left, trying to entice her male. She positioned herself with her back to her partner and began the upward movement of the head seen in the video, along with the vocalization that accompanies it.This is how one western gull tells another that he or she wants food or sex.
However, just as I hit the record button, the male gull violently denied her, giving her instead a stern bite to the neck. This occurs in the video's opening moment.
We observed similar interactions among other western gull pairs, albeit without the violence.
Odds and ends
- Canada geese have arrived on Alcatraz. We can't be everywhere on the island at once, but our sense now that we're hosting around eight or so. The canada goose is divided into several subspecies and one of the next items on our amateur bird detective agenda is to find out what subspecies our geese belong to.
- The pigeon guillemots have also returned, seemingly going from invisible and absent to ubiquitous and loud in about a week.
- Brown pelicans now fly over the island with regularity. As recently as a year ago, pelicans not sick or injured avoided Alcatraz as if it were the center of evil and dishonor in the bird universe. While this isn't exactly a sensational observation, it's no less baffling for that. What has changed?
- Numerous brandt's cormorants have been seen on Alcatraz and in the waters around it. We can't wait to see if they return to breed.
- The common raven pair has been far less visible over the last week or two.
- The falcon had a bloody adventure recently. Stay tuned to MAGANRORD for BourbonHawk's upcoming post. Here's a little taste:
I wonder what she has there.
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