Rarity: A Brief Study of Herons

Scarborough Marsh in Southern Coastal Maine is no stranger to rarities. This year alone we’ve had visits from White-Faced Ibis, American Avocet and a Black-Necked Stilt. Some identifications are easier than others, but often patient study is required to reveal the correct identity of a bird.

Great-and-Snowy

Here we have a Great Egret and a Snowy Egret. The Great Egret is a much larger bird with a longer beak and a longer neck. The Snowy is not just more compact, but it also has bright orange feet, which of course, are not visible while it is wading. Size is not always a good indicator unless you can accurately gauge distance. Relative size helps, for instance when the two species are standing side by side.

During a fly-by, the yellow feet become visible and the identification is made all the more easy. But there are other herons that are close in size to the Little Blue Heron and often congregate with them.

In this gallery we first see a Snowy Egret and next we see a Little Blue Heron. I guess the Little Blue Heron is to the Great Blue what the Snowy Egret is to the Great Egret in some ways. But the last bird, looking at it what would you say it would be? Click on the pictures to make them larger and really take a good look. Examine the following:

1) The leg color and the foot color too.
2) The color of the lores, that space between the eye and the bill.
3) Then look at the bill itself.

Note that I told you to ignore the most obvious “field mark.” The color of the bird itself. This bird is an immature Little Blue Heron. The leg color, the lores, the color of the beak all match the adult little blue. As a juvenile the Little Blue congregates with the Snowy Egret and it takes a little time to make the distinction between the two species.

Molting-Little-Blue

So what about this bird? This bird looks pretty confusing right? Its like the bird equivalent of a softserve chocolate-vanilla twist. This is a juvenile Little Blue molting into it’s adult plumage. For about a year the Little Blue keeps its white feathers and then makes the transition to adult plumage. Again, if you ignore the feathers you can see how it compares with the other two images. BUT, believe it or not, there is a species of bird that is a purple-ish blue with white and its the same general size as the Snowy Egret and the Little Blue Heron. This is the Tri-colored Heron.

Tricolor-NJ

Generally I find the shape of the Tri-Colored to be more reminiscent of the Great Egret more than the Snowy Egret or the Little Blue Heron. Not very visible in this image is a white stripe that runs down the neck to the belly. And that is where we come to the rarity. While the Tri-Colored Heron is not all that common in Maine, the other common waders are easily eliminated when trying to identify the bird in the next picture. The Black-Crowned Night-Heron, Green Heron, American Bittern, and the Glossy Ibis don’t remotely look like this bird…

Tricolored-x-Snowy-Hybrid

Its got that bluish color like the Little Blue and resembles the juvenile Little Blue molting. But it also has that characteristic white strip of the Tri-colored Heron. The bill is pretty stout and colored like the Tri-colored Heron and it has dark legs and orange feet…

This bird is presumed to be a hybrid between a Tri-Colored Heron and a Snowy Egret, yet most resembles the juvenile Little Blue in molt when you look at it quickly. So the obvious clue, the feathers, is the most deceptive clue, and what you might easily overlook is actually quite a cool find.

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