December Quiz: Answer

To refresh your memory, here is the photo from December’s Bird Quiz. The bird was seen in Texas during the month of December. Don’t read any further if you want one last chance to identify this bird.

12_BocaChica-Brownsville-TX_PLH_3746

Hopefully you recognize this as a gull. If not, please scan through your field guide and take a look at the gulls. They’re all quite similar—same shape, approximate size, basic color pattern (especially on the wings), beak, etc. But even though these birds are clearly related, it is possible to look for slight differences. This is what makes it possible to tell them apart.

Before we go any further, I’d like to clarify something. There is no bird officially named a “seagull.” They are simply “gulls,” members of the family Laridae. Perhaps that’s because they’re often found inland. Some are definitely marine—I’d be pretty excited to see a Western Gull here in Colorado—but we do get other gull species in abundance, particularly around bodies of water and at the city dump. You can go ahead and call them seagulls with your non-birding friends—it will keep you from looking too geeky. But when you’re birding, you’ll gain more “field cred” if you get it right.

Now, how do we go about identifying which gull this is? Gulls are tricky. They take seemingly forever (it’s actually two to four years) to mature, and go through a series of different plumages in the meantime. I am not going to deal with immature birds in this post. It would take an entire book.

To make matters worse, gulls frequently hybridize. I’ll skip that as well. This gull is a mature adult, and it appears to be a purebred.

First of all, gulls can be divided into those with white heads and those with black heads. The white-headed species tend to be larger, and are harder to tell apart. (Hint: check the color of the eyes and legs.) Those with black hoods are smaller. They tend to avoid the big guys (but not always).

Unfortunately, those easily-seen black heads are only black during the breeding season—which is definitely not in December. In non-breeding birds, the black fades out to a fringe of darker plumage, much like a man who is going bald. This can look deceptively like an immature bird. In addition, the heads of many white-headed gull species turn speckled brown in winter. However, as those are brown rather than gray, with a bit of practice you’ll confidently distinguish them.

Other parts to examine closely include the shade of white/gray under the wing, and the color of the eyes, beak, and feet. These can be hard to see on a flying bird at a distance. Lucky you, you have a photo!

To describe this gull: it has a black beak, dark eye with weird white eyelids, we can’t see the feet, and it has dark splotches on the head. We can’t tell the size, either.

Those dark splotches narrow things down to the black-headed gulls: Franklin’s, Laughing, Bonaparte’s, Sabine’s, Black-headed, and Little Gulls are the North American choices. (Juvenile Kittiwakes also have black beaks and black smudge marks on their heads but these look more like earphones—and they’re definitely not found in Texas.)

Let’s look at the black beak. Many gulls have black beaks in winter, even though they turn yellow during the summer. Sabine’s Gull has a black beak with a yellow tip. Also, they migrate off the Pacific coast to the southern hemisphere, so it’s extremely unlikely that I’d see one in Texas in December. We can rule that out.

How about the eyes? Those white “eyelid” markings, with the black circle around the eye, are pretty obvious. We can eliminate the Little Gull based on the eyes, plus, in winter, it’s normally only seen along the mid-Atlantic seaboard. Black-headed gulls are mainly found along the Canadian Atlantic coast in winter. My field guide doesn’t have any indication that they make it to Texas. Its head has two black stripes, not at all like our bird. Cross it off. Bonaparte’s Gull also lacks the black ring around the eye, plus its head has dark ear-spots, not the general shading of our bird. It does occur in Texas in winter, but we can cross it off as well.

We’re down to two species, both with black beaks, black eye-rings, and black heads in summer. Franklin’s Gull is familiar to Colorado birders as a summer gull, but it only passes through Texas during migration. Still, we could have a straggler. Laughing Gulls are common all year along the Texas coast. It’s more likely, but we want to be sure.

Now to look at the black remaining on the head. In Franklin’s Gull, it’s a single, solid hood, from the top of the head to the middle of the back of the head. Laughing Gulls have a white patch in the middle of the dark area—just like the bird in my photo.

Yes, it’s a Laughing Gull, one of the most common hooded gulls along the Gulf Coast. Here are some more photos showing the black legs and variability of the head plumage. The final bird is a Bonaparte’s Gull, for comparison. Of course, the leg color makes ID easy—when you can see it!

LaughingGull @Florida Keys 1jan08 LAH 875

LaughingGull Lineup @Florida Keys 1jan08 LAH 872

The 2nd and 4th birds are 1st winter juveniles; the 5th is a 2nd winter bird.

Laughing Gulls @PadreIs LAH 031

Bonaparte's Gull_KillDevilHills-NC_LAH_LAH_2840_filtered

 

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One Response to December Quiz: Answer

  1. careymoonbeam says:

    Wow. Thanks! So cool you have enough photos to pull out comparison ones for us too.

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