On December 29 we were walking around at the Gilbert Riparian Preserve when we heard a tremendous amount of honking coming from one of the ponds – a flock of Canada Geese was in residence. This is the right time of year to spot a Snow Goose or two mixed in here, so I scanned the flock, and sure enough…
But is that a Snow Goose? (These photos were taken using the 200 mm lens I got for Christmas. The bird was pretty far out.)
There are two very similar-looking species of white goose in North America, the Snow Goose (the larger, more common one, which I’d seen before) and the Ross’s Goose (the smaller, less common one, which would be a new life bird for me). The usual way to tell them apart is by examining the head and bill. Ross’s Geese have rounder heads and shorter bills. Their bills have some bluish or greenish coloring around the base and typically don’t have the black “grin” that a Snow Goose’s bill does. To further complicate things, the two species hybridize pretty regularly. So what’s this one? I wasn’t sure, and since Ross’s Goose would be a lifer, I posted the (admittedly crappy) photos on Twitter and Facebook. On Facebook I directed my question to an old college birding buddy who’s now a PhD student in ornithology, while on Twitter I just posted a general plea for help, which led to someone there forwarding the photos to an ornithologist acquaintance of his own.
The bill coloration looks Ross-ish, but in that last photo the head shape and bill size look more Snow-ish. My Twitter follower and his ornithologist friend decided it might be a hybrid. My ornithologist buddy from college, on the other hand, declared that to be a cop-out and put his money on Ross’s Goose, albeit maybe one with a slightly bigger bill than normal. When I checked eBird and saw that someone else had reported a Ross’s Goose at the Gilbert Water Ranch the same day, I decided to call the bird in these photos my life Ross’s Goose.
Yes, birders really do spend their time thinking about and debating this sort of thing. Here are a Snow Goose and a Ross’s Goose so you can make your own comparison. What do you think?
(Let’s all agree to pretend I took the photo like this on purpose to be artsy. I meant to focus on the plants in the foreground instead of the birds.)
I’m in Arizona this week for Thanksgiving break. Took this photo yesterday at the Gilbert Riparian Preserve – white pelicans aren’t terribly common around here, so this was a treat. We also got a great look at a Peregrine Falcon perched on a power pole. It makes a change from hunting for crossbills in the bog at home.
Recently I shared the news that feral cats had been eliminated from one of my favorite birding spots in the Valley (that’s the greater Phoenix area to you not familiar with Arizona lingo), the Gilbert Water Ranch. Last night we went for a walk there around dusk. In winter, the ponds are full of many species of ducks, but at this time of the year things are much quieter.
In fact, other than one lone Cinnamon Teal the only ducks I spotted were manky mallards like these, begging for handouts.
Summer is when the Black-necked Stilts and American Avocets turn up, which are always a treat. We saw a few of those, but a lot of the ponds were dry, their beds plowed. Not sure what purpose plowing them serves. (As I explained in my previous post about the Water Ranch, it’s technically a wastewater treatment facility, where graywater is allowed to sink into the ground and recharge the water table.)
We also saw… one lone gray cat. Sigh. I guess they were a little premature in announcing the total extirpation of the site’s feral cat population.
Even if summer is a relatively quiet time for water birds in southern Arizona, it’s still pleasant to walk along the paths, all landscaped with native plants. It’s easy to forget here that you’re in the vicinity of the sixth most populated city in the country.