round here, the raucous call of returning herring gulls is just one more sign of the advancing of the seasons. They begin showing up around mid-March at their favored nesting spots on area lakes— typically small, rocky, treeless islands— where they start staking out the best nooks and crannies for their nests.

In many cases, it’s a long wait, since gulls don’t start laying their eggs until the lakes thaw, which cuts off easy access to their nesting rocks for egg lovers like foxes, wolves, and coyotes.

With the ice typically encasing area lakes through April, this time of year can be lean pickings for gulls—which rely mostly on aquatic life for food. That’s why most of the gulls starting to show up right now typically retreat to open water, like Silver Lake in Virginia, in the evening. You can, sometimes, catch the aerial stream of gulls flying back and forth in mornings and evenings.

This time of year, you’re most likely to be seeing herring gulls, which are the largest of the gulls that breed in the mid-continent. In fact, there are really only two gulls that you’re likely to find breeding here— the herring gull and the significantly smaller ring-billed.

The two gulls are pretty easy to distinguish. While adults both have yellow bills and the familiar white and gray plumage we associate with gulls, the ring-billed gull has a prominent black ring near the tip of its bill, and its legs and webbed feet are yellow. The herring gull, by contrast, has pink legs and feet and adults sport a red dot on the lower half of their bill, near the tip. The herring gull is also a lot bigger— about the size of raven— while the ring-billed gull is roughly crow-sized.

Their larger size makes herring gulls more aggressive in defense of their nesting areas. Herring gulls, like most gulls, are colonial nesters, which mean they gather in large flocks in prime nesting locations. The gull rookery on Lost Lake, a quarter-acre sized slab of bare granite that rises from the waters not far from the public landing, is home to more than a hundred nesting pairs during the summer.

With that many birds on the small island, any marauding predator or clueless human is quickly subjected to assault from the skies. Herring gulls aren’t at all shy about sneak attacks, in which they fly up from behind and whack intruders on the head with their feet. They also like to take advantage of such attacks to drop a nice load of steaming gull poop down your back. And yes, I have personal experience with this delightful behavior.

While we think of gulls as pretty common these days, that hasn’t always been the case. Like most birds that rely on the aquatic food chain, gull populations nosedived starting in the 1950s, mostly as a result of the buildup of DDT in the aquatic food chain. The ban on the use of the DDT in the U.S. allowed the population of gulls, as with eagles, peregrine falcons, pelicans, and many other aquatic-feeding birds, to eventually recover. Today, they are common once again. And, like us, they’re here in early April, looking for signs of spring.