Thursday, September 1, 2022

Bird quiz answers

The moment you've been patiently awaiting: answers to the challenging photos I posted last week. If you haven't seen the quiz yet, click here to try your hand before you read today's answers.

And here we go!

1. January 2022, Arrowhead Marsh, Oakland, CA

A duck in bad light. Woo hoo!  It's compact, so likely a diving duck, and it appears all dark, so you might think female Bufflehead or Ruddy Duck. But the bill is not right for either: too big to be a Bufflehead and too small to be a Ruddy Duck's super ski-slope bill. So what other dark ducks are there? Well, if you're in an Oakland estuary in winter, e.g., Arrowhead Marsh, you might be seeing scoters.

And that's in fact what this duck is: a female Surf Scoter, maybe an adult, maybe a first-year, I can't tell. From this other angle the bill definitely looks more scoter-like, and you get a hint of the white just dusting the base of the bill. Female Bufflehead's white cheek would be much brighter, and a male winter Ruddy's cheek patch would also be much easier to see, even in poor light. A female Ruddy's striped face might be difficult to see in this light, but still her bill would be a different shape. Check your field guide for comparison.

2. January 2022, Berkeley, CA

Not a ton of field marks to go on here, but there aren't a lot of birds that might perch on a monument up high. Pigeon? Maybe. Gray head, long body might fit. But the wingtip that extends past the tail wouldn't fit a pigeon, and even from this unusual angle the bird's posture looks more vertical than a pigeon's might be. It also looks slimmer than I'd expect a pigeon to be.

As it turns out, it's not a pigeon but a pigeon's worst nightmare: a Peregrine Falcon. Now you can see the hooded appearance, dark back, and white belly that identify these both as Peregrines, even at a distance. These birds are Annie and Grinnell, a pair that nested on UC Berkeley's Campanile from 2016 to 2022. Grinnell died this year, but new male Alden quickly took his place and helped Annie fledge two chicks.

3. March 2022, Inverness, CA

Brown bird on the ground in Northern California in late winter. By the habitat, season, location, plumage color and general body shape we might think Hermit Thrush or California Towhee or some other kind of sparrow. 

A Hermit Thrush would have a contrasting rusty tail, which this bird doesn't, so we can rule that out. A California Towhee's chest and belly are unmarked, its vent area is rusty, and its tail is longer, so cross that off. 

Some other kind of sparrow, then? Its back is unmarked uniform grayish brown, unlike a Song Sparrow or many other winter sparrows, but it does have markings on its underside. Thus, you can go ahead and call this a Fox Sparrow, specifically the Sooty form found on the Pacific Coast. Now that it's turned around, its bicolored bill shows, as do the triangle-shaped chest marks that merge into a central breast spot (or blob).

4. March 2022, Inverness, CA

Black and white birds, not much of a tail, one shows a red cap and a light breast. Black, white, and red usually mean woodpecker, and that would be right. In California, the black and white woodpeckers are Downy, Hairy, Nuttall's, and Pileated. However, all but the Pileated have white checks or other patterning on the back or wings, not solid black. And these are too small to be Pileateds.

The only California woodpecker with solid black and white (no bars or spots) and a good amount of red on the top of the head, not the back, is the Acorn Woodpecker. In this photo you can see the clownlike face and light iris on the top bird, and the bottom bird shows its sharply pointed woodpecker bill. The top bird also shows the pointed tail feathers typical of woodpeckers. These birds sat and preened in the light of sunrise before flying off to start their day.

5. March 2022, Inverness, CA

The upright posture, no visible legs, and choice of perch should say bird of prey to you. Is it an owl with all that speckling? No, owls have big round heads, and this bird's head is not big enough. The bulky body indicates a buteo, the genus of soaring hawks like the Red-tailed Hawk. Red-tails are widespread and common, so let's apply the Red-tail test. Does it have a red tail? No. But young Red-tails don't have a red tail; their tails have alternating thin light and dark bands. Does it show light colored scapular (shoulder) feathers shaped vaguely like a V against darker back feathers? I don't see that field mark, so I don't think this is a Red-tailed Hawk.

I also don't think this is an accipiter, the genus of Cooper's and Sharp-shinned Hawks. Their tails are banded like this but are much longer relative to the body, and the body overall would be less bulky than this bird.

This bird's tail shows alternating thin white and thick dark bands and is not very long. Its back is speckled, and its wings have a black and white checkerboard appearance. Those field marks add up to make it an adult Red-shouldered Hawk, sometimes called "the accipiter of the forest" because of its preference for trees and its very vocal nature, much like accipiters. This bird perched in the light of sunrise and preened several mornings in a row. It vocalized a lot then took off to pursue its day.

6. May 2022, Tigard, OR

Yellowish green songbird....goldfinch? No wing bars. Tanager? Same, no wing bars. Kinglet? It's all about the wing bars again. So that leaves...

A spring warbler! Yay! Here in the PNW we have only about a dozen warbler species to tackle, unlike the midwest and east with their three dozen. This bird showed up adjacent to my yard, and I first noticed it because of its voice. I took a ton of photos and loved that many of them showed just the tiniest hint of a field mark and would be great quiz photos.

So, no wing bars: that rules out a lot of warblers, like Yellow-rumped and Townsend's. Orange-crowned Warblers don't have wing bars and could be colored like this, but look at the bit of its head peeking out. It's gray. And I can see white around the eye. But there's a gray-headed form of the Orange-crowned Warbler with eye arcs and a light eyeline, isn't there? Yes, but from what I can tell from Sibley's, they are also much less yellow, so this bird's body color wouldn't fit. Plus, I don't see a light line through the eye, only the arc above it.

How about a female MacGillivray's? Maybe, but the white above the eye looks like it might be continuous rather than broken...hard to tell, though. And honestly I don't have enough experience with MacGillivray's to point out any other big differences.

So that leaves us with a warbler, no wing bars, a gray head, and a (possibly) complete white eye ring. If you look really close you can also see the tiny reddish feathers on its crown, making this an adult male Nashville Warbler.

Tell us how you did in the comments!

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