Every year, winter brings with it to the USA a host of birds not present in any other season. There are sparrows that are only present in winter, raptors that are only present in winter, and many others. This winter, there has already been a notable irruption of Snowy Owls, with reports of them coming in from all along the east coast. One of the signs that birders first look for to indicate the coming of colder months are geese flocks migrating south in that characteristic “V” shape, and these arriving geese flocks bring with them a whole manner of geese to consider; Snow Geese, strange hybrid geese, and rarer occurrences, Barnacle Geese and Pink-Footed Geese among them.
But what about unusual geese that don’t have bubble-gum pink feet? Many unusual geese don’t look so unusual; many of them look just like Canada Geese, and this is where identification of all the weird geese of winter gets confusing. Is it a Lesser Canada Goose or a Cackling Goose? It seems every flock of geese has few “runts” who seem smaller and darker than the rest, or have a higher pitched call, or an odd, bold white neck collar. Proving that these geese are something different can be quite a challenge, but there are some ways to narrow down the possibilities when deciding if a goose is really different from the rest of the flock. Many of the “runts” in a flock of geese are just that – runts. Geese that are normal in every way except for their size, and there is usually only an impression of small size when you first look at the bird. Here is a test I use to determine if a goose is really and truly unusually small: after finding a small goose in a flock, take some pictures of it, and then walk away. Continue down the trail you’re hiking, scan nearby shrubs for winter sparrows, but stop looking at the geese. Bird the area for an hour or so, and then go back to the geese flock. If you can quickly pick out the same goose as before, it is probably something different. If you find yourself going from small goose to small goose looking for the bird, then it’s just a runt – if it were something different you’d have no problem relocating it. Of course there are other field marks. If the bird has the obvious small bill of a Cackling Goose, than there isn’t any need for that kind of test.
Richardson's Cackling Goose
There is a small goose that has taken up residence with the other geese in a pond near where I live. It’s noticeably smaller, and I could easily find pick it out from the other geese three days in a row. I observed it enough to realize that it had an unusually high-pitched call, and have enough comparison photos of it next to Mallards to make it clear that is definitely not just a typical Canada Goose. But it doesn’t have a small bill, eliminating Cackling Goose as a possibility. Geese like this one are the ones that cause birders to tear their hair out in frustration as they rifle through field guides and click through countless internet photos of Lesser Canada Geese, Cackling Geese, and everything in between.
Lesser Canada Goose Small geese like the one in the photos above are difficult to identify – we can eliminate Cackling Goose because of the bill, but now what? Canada Goose x Cackling Goose hybrid? Lesser Canada Goose? Neither option is likely, but the bird is clearly different. Of the other options, parvipes is the most "likely." There are many other factors, like bill-length measurements, height and weight measurements, that can also be used, but in most cases it isn’t possible to obtain these. So, if the measurements are unobtainable, then take lots of pictures, especially comparison shots. It may seem better to get a high-quality, close up photo of the bird, but that's not as helpful because unless there is another goose or a Mallard in the photo, there aren’t any features that can be used to distinguish the bird from a normal goose. Comparison shots of the bird both in and out of the water are often necessary. As you can see in the photo, the goose is clearly small, but without the normal goose or the Mallard female in the background for comparison, it would be impossible to tell from the photo that there was anything abnormal about the bird.
It’s really easy to see a runt and believe it’s a different species or subspecies, but using some of these basic strategies should help really determine if the goose is an unusual one.
By
Patrick Carney
It’s really easy to see a runt and believe it’s a different species or subspecies, but using some of these basic strategies should help really determine if the goose is an unusual one.
By
Patrick Carney
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