Tuesday, February 1, 2011

A Wild Goose Chase

Well, it's January, time to study ducks, geese, and gulls in the arctic California winter.  So I slapped on shorts and a t-shirt, and headed out.  Weird Goose Number One hangs out at Earvin Magic Johnson Park.  Clearly, this bird is half Anser and half Branta. 
I called it half Canada Goose (Branta canadensis)-half Greater White-fronted Goose (Anser albifrons).  Norm Vargas says that looking at the shape of the bird's size, and how at rest its tail points upwards, he thinks the bird is half Graylag Goose (Anser anser).  This appears to match Kevin McGown's pictures of hybrid geese on the East Coast.

For comparison, here are a Cackling Goose, Branta hutchinsii leucopareia  (formerly the tiny race of Canada Goose) and a Greater White-fronted Goose feeding among the Canada Geese in the same flock at Magic Johnson Park:
Notice on the Canada Goose in the bottom left of the photo, below, that its head and bill have different proportions, and the actual shape of its head is different.  On Canadas, the bill slopes continuously with the face, while on Cackling, the bill sticks out from the face:

I just had a pair of Cackling Geese calling in flight at Legg Lake, and they sound really different from the familiar Canada Goose call.  For a well-produced in-depth recording that compares their sounds, click here.

And now, for a Weird Gull

Start counting gulls that are standing up along the edge of the concrete wall, ready to jump into the water.  The 2nd one from the left puzzled me for the following reasons:  Yes, he sorta kinda looked like a Western Gull, and he was in the middle of a flock of Western Gulls of various ages, but his body was noticeably smaller than the other Western Gulls, and his bill size and shape was proportionately smaller and thinner (even when compared to other immature Western Gulls).  Any thoughts?

Weird Goose Number Two really threw us for a loop.  We were on an organized field trip at Seal Beach National Wildlife Refuge, which is inside an active U.S. Navy base.

We were looking at a large flock of Canada Geese a couple hundred yards in the distance, partially obscured by a grassy knoll that was two or three feet high.  Susan Gilliland and I simultaneously noticed a swan among the geese.  The swan had a white head and neck, with a black bill.  Looking at the size of the bird's body, and its bill's shape, we assumed it was a Tundra Swan, and not a larger Mute or Trumpeter Swan.  It would stick its head up, look around, and duck back down.  We drove closer, and stayed inside the van, to avoid spooking the birds away.  These pictures were taken through the tinted glass side window of the van:
 If you can't see the bird very well, click on the photo, and it will come up on a separate page, in a larger size.  Here's another one of the same bird:
I have no idea if this Canada Goose is merely a leucistic genetic mutant, or merely a hybrid.

Hey, there was a Reddish Egret on base:
The bushes on the left side of the picture below held Belding's and Large-billed Savannah Sparrows, along with at least one Nelson's Sharp-tailed Sparrow.  The previous week, three Nelson's were seen.

View is looking northeast, towards 10,000 foot high Mount Baldy, 56 miles away.  Well, okay, it's actually 10,068 feet high.

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