The term “snowbirds” sometimes refers to people who head south to avoid the cold and snow of winter. There are some real birds who, in recent years, have been doing just the opposite by spending winters in the Northeast.

Observations by bird watchers can provide long-term data to document these trends.

I keep an annual “yard list” of birds that I observe around my habitat. Over the past 19 years, I’ve identified 107 species from our 4.5 acres of woods and fields. The most species recorded in any one year was 78 (2023). Beyond the raw numbers, I’ve watched the diversity of birds grow and witnessed changes in the seasonal occurrence and overall abundance of some species.

On New Year’s Day, I was surprised that the first two species of this year were a Carolina wren and a red-bellied woodpecker, two species that were not on my list two decades ago. Changes in land use, climate and various other factors are making some birds more common while others are in decline.

According to NH Audubon’s “State of the Birds” report, the Carolina wren was “extremely rare in the state until the 1990s, occurring only as a vagrant or occasional winter visitor.” 

As you might imagine from its southern-sounding name, it was more common in the warmer regions, breeding throughout the mid-Atlantic states to Florida and in the mid-west. From the early 1990s until around 2010, reports of this bird in New Hampshire were uncommon.

Since that time, their numbers have increased dramatically throughout the state, south of the White Mountains.

I recorded my first Carolina wren in 2011. They have been year-round residents on our property for the past two years. It’s easy to know if these little birds are in your neighborhood. Like most wrens, they are quite vocal. The male sings a loud “teakettle-teakettle-teakettle” song and other punctuating chatters.

If you glimpse one of these songsters, look for a distinct white eye-stripe, an erect tail and relatively long beak. The male and female have the same soft brown plumage and form a life-long and year-round pair bond. I’ve had the pleasure of watching a pair snuggle together in the abandoned phoebe nest each cold night for the past few weeks. They now seem destined to be regular entries on my yard list.

Red-bellied woodpeckers have been consistently on my yard list since 2011. For most of those years, they have been present in winter in addition to the breeding season.

Data in NH Audubon’s Breeding Bird Survey reflects that trend across the central and southern parts of the state. The traditional breeding territory of these woodpeckers is similar to the Carolina wren.

Red-bellied expansion into our state began around 2000 with a dramatic increase around 2010. The name of this bird can be confusing because the wash of red on their belly is barely visible.

A more prominent field mark is the red on the top of the head of the male. Both male and female have red on the back of their head or nape. Their back feathers are black and white like some of our other native woodpeckers. The underside is tan.

Keep your ears open for the shrill calls of these woodpeckers. The Cornell “All About Birds” reference states that “a rolling “kwirr” of “churr” may be given by either the male or female. A gruff “cha, cha, cha” also pierces through the woods if they are nearby.

The northern invasion of this species may relate to an increase in some invasive insects including the woodboring larvae of the emerald ash borer. The availability of dead trees for nesting cavities also has likely helped these woodpeckers find favorable nesting sites.

As with the Carolina wren, the red-bellies take advantage of suet and bird feeding stations put out by those of us who enjoy bringing wild birds closer to our homes.

The changing climate may also be contributing to the population increase of these two species, just as it is having the opposite effect on other birds.

It’s unknown whether the trend of southern species spending more time in northern states will continue. However, it’s nothing new. Some birds that we most enjoy, including northern cardinals, American robins and eastern bluebirds were once rare or only seen during the summers in northern New England.

If trends in bird populations are of interest, visit NH Audubon’s State of the Birds.