Tuesday, December 15, 2015

A Ross's Goose with Snow Geese

On Sunday I was browsing Birding Ohio when I saw a report of two Snow Geese and a Ross's Goose in Lancaster, Ohio. The semester had just ended and I was back in my hometown of Circleville, a mere 30 minutes away from Lancaster, so I thought "why not go see them?" I got in my car and headed off to see the three rare geese!

Rare Birds in Urban Areas
I made the drive and arrived at this incredibly wild and biodiverse... retention pond. Okay, maybe not so wild, and not so biodiverse, but sometimes really strange things show up in ponds like this. Take for example the three white geese in the photo above (2 on land, 1 in the water).

Snow Geese Ohio
I pulled up closer to the geese, using my car to act as a blind. People don't always realize how useful of a blind a car can be; animals tend to equate humans with danger, but cars are just those big, quickly moving things that never really bother them. As a result, many animals will allow for a closer approach by car than they would with you trying to sneak up on them. The two white geese pictured above are the Snow Geese in question.

Snow Goose Ohio

The Snow Goose is my favorite goose. It's also a species that's eluded me for years. This year, however, has been different! I recently got my lifer Snow Goose in Athens, which I wrote about here. Now two more Snow Geese! The Snow Goose is a rare, but regularly occurring, bird in Ohio. They breed in the high Arctic and migrate to locations east and west of Ohio. During migration, they use flyways that bypass Ohio completely, and the vast bulk of individuals never visit the state. However, every year a few dozen individuals migrate through Ohio. These individuals end up in Ohio for a variety of reasons; some are blown off course by weather fronts, others might be juveniles who don't have this "migration" thing down yet, and others might be individuals who have some sort of a flaw with the navigating portion of their brain. Birds use various mechanisms to migrate, including Earth's magnetism, star-navigation, and location of sunsets, and if the part of their brain that facilitates navigation is either deformed or injured, you might end up with a bird that knows it needs to migrate, but just doesn't know exactly where to go. Generally speaking though, since we are so close to the flyways Snow Geese use, the ones that show up in Ohio are probably just individuals blown a bit off course by weather.

Ross's Goose vs Snow Goose
The report mentioned a Ross's Goose was also present, and a quick check of all three individuals made it clear who was who. In this photo, the Ross's Goose is the one in the front, while a Snow Goose is behind him. The Ross's Goose looks really similar to the Snow Goose at first glance, right? Further inspection reveals some subtle differences. But first, how do you tell if the white goose you might be looking at is a Snow or Ross's Goose, and not just an escaped white domestic goose? Look at the wing-tips! In a Snow/Ross's Goose, the wingtips will be black, as you can see above, while a white domestic goose will be completely white. Since these guys have black wingtips, how can you now differentiate between the two species? First, notice that there's a nice size difference between the two; the Ross's Goose is only about half the size of a Snow Goose. Obviously size can be deceiving in some circumstances (especially if you don't have a nearby Snow Goose to compare it to), so identification must rely on other characteristics. The most tell-tale field mark, in my opinion, is the beak. Notice how the Snow Goose has a large beak that seems pretty proportional to its head. Now, compare that beak with the tiny, thin beak of the Ross's Goose. If you see a small-looking white goose with a tiny beak, you've probably got yourself a Ross's Goose. Another thing to take into account is the length of the neck. Snow Geese have long necks, while Ross's Geese have shorter, stubbier necks, but once again this can be deceiving in some circumstances.

Ross's Goose Ohio
The Ross's Goose was the more exciting of the two species in question. Although Snow Geese are rare in Ohio, they occur in mind-blowing numbers elsewhere. The Ross's Goose, however, has a much smaller global population, making them uncommon even in places they're supposed to be. Now, couple that with the fact they aren't supposed to be in Ohio, and you've got yourself a very exciting goose! Like the Snow Goose, the Ross's Goose breeds in the high Arctic and migrates to the southern US and northern Mexico. However, the range of the Ross's Goose is much more restricted than the range of the Snow Goose. Interestingly, the Ross's Goose has been expanding in both population and range over the last 40 years, resulting in more and more individuals turning up in places that they normally wouldn't. With this recent trend, it is possible that the Ross's Goose might become a much more regularly-occurring bird in Ohio.

Snow Geese with Canada Geese
It was wonderful to see these geese so close to home. This year has been filled with rare and interesting birds, and hopefully this trend continues into next year.

Thanks for reading!

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