In a high school writing class years ago, I wrote a compare-and-contrast essay on how to tell apart different species of Maine gulls. Even then, I was  both fascinated with birds and bent on encouraging people to take a second look at what’s usually dismissed as ordinary. My life as a bird nerd had begun. And 30 years later, I still find gull-watching to be a satisfyingly challenging exercise, especially in winter when most of our more colorful birds have fled to warmer climes. So before you scoff at the idea of watching those scavenging “rats with wings,” pay a little attention to this overlooked but ubiquitous family of birds.

An added bonus with gull-watching:  Pou don’t have to comb the fields and forests, tromping through snow in sub-zero temperatures to find them. You can often observe them from the warm comfort of your car. If you look carefully at the gulls mobbing a fishing boat, perched on harbor pilings, or waiting hopefully atop the roof of McDonald’s, you should be able to easily pick out several different species. And this time of year, when our local gulls have been joined by several northern species spending their winter in the relative warmth of the Maine coast — just call us the Riviera of the Arctic — some of those gulls might be real finds.

Let’s start with the quintessential “seagull,” the herring gull, found almost everywhere in North America. This is the typical white gull with black-tipped grey wings, the one tourists like to photograph perched next to a scenic waterfront landmark or raucously begging for scraps at picnic areas. Common enough that it can be found almost anywhere in the right season, the herring gull is a year-round resident here on the Maine coast. If you see a gull around here, odds are high that it’s a herring gull, which makes it the visual standard against which to compare other gulls.

The ring-billed gull is similar to though smaller than the herring gull, with, yes, a black ring around its bill. Although more common in summer, a few of these will stick it out through the winter. In a mixed group of both herring and ring-billed gulls, you can easily pick out the smaller species. For some reason the ring-bill in particular prefers hanging out at McDonalds, maybe because the pickings are easier and it doesn’t have to work so hard fending off larger gulls.

A third gull found here year-round, the great black-backed gull, is one of the largest gulls in the world. This big, aggressive bird is very distinctive, sporting an all-over black back and wings. The black-back definitely uses its size to its advantage. More than once I’ve seen one attack and kill a smaller gull, and it’s notorious for picking off eider chicks in the summer, as well. There are fewer of these around than herring gulls, but they certainly stand out in a crowd. (And just to keep things interesting, there’s also a lesser black-backed gull, which turns up around here every now and then.)

In addition to these three regulars, a keen eye may discern other species typically only found here in late fall – winter. Bonaparte’s and black-headed gulls are very small with black commas behind their eyes — all that remains of the black hood of their summer plumage (similar to our summer resident, the laughing gull).

Recent Christmas Bird Counts have turned up a black-headed gull or two in Rockland Harbor, as well as a several small groups of Bonaparte’s. Bonaparte’s gulls are frequently visible from the Rockland Breakwater and the North Haven/Vinalhaven ferries. I’ve also seen winter flocks congregated around open water on Chickawaukie Lake. The more common, pigeon-sized Bonaparte’s has a black bill, while the black-headed sports an orange one. Because of its size, the Bonaparte’s in particular can have a twinkling look as it flits in the air, especially when you come across a flock of them feeding together.

Another possible winter find is the Iceland gull, similar in size and shape to a herring gull but featuring much paler wings without the black tips. Some adults can indeed look almost white. For some reason I’ve usually found this gull on beaches, pecking among the stones below the Owls Head lighthouse, for example, or hanging out on a waterfront strand near Portland’s Eastern Prom, where I’ve also seen the similar but larger glaucous gull.

Most waterfronts offer good gull habitat, as well as less savory but noteworthy places like the Augusta landfill, although the real hotspot for gulls in Maine is Down East. The Old Sow, a giant whirlpool in the turbulent waters off Eastport, wells up with krill and tasty aquatic critters, attracting  thousands of gulls. A birder friend recently spotted nine gull species in one outing there, including all of the above-mentioned species, black-legged kittiwake, and the rare little gull (of which he actually saw four!)

And then there was that winter a few years ago when I drove to Gloucester, Mass., in a snowstorm to see my first-ever ivory gull, one of the most beautiful birds I’ve ever seen. Up in the Arctic,  you can find them getting down and dirty in a seal carcass, just like a herring gull here, but in New England the rarity of this errant bird combined with its angelic, pure white plumage elevate it to something truly special.

Who knew gulls could provide hours of such good, clean fun? On a sunny winter afternoon that’s too cold for a walk but too lovely to be wasted inside, pick up a good bird book, drive to a nearby harbor, and see how many gulls you can identify. My basic descriptions here were of adult birds. So if you’re observing a mixed-age flock, things can get really interesting. Once you think you’ve got the adults figured out, you can take things up a notch by trying to tell apart the motley juveniles. The herring gull, for instance, doesn’t take on full adult plumage till its fourth year, and looks very different after each yearly molt preceding full adulthood. I find myself giving a young herring gull a second look all the time, wanting to turn it into something exotic. You just never know. With bird identification, it’s all about paying attention to the details — and that’s what makes it so enjoyable for a bird nerd like me.