Nature Connection: The Wonder That Is Migration

In our area May is perhaps one of the most miraculous times of year. It is when migrating birds appear in large numbers after a long, quiet winter.

Birds migrate for several reasons, but food and reproduction needs are at the top of any list. Insect eaters, such as warblers and flycatchers must follow the food source. In New England, spring and summer are busy times for insects of all kinds but fall and winter are times when insects become scarce or even non-existent. Those birds that feed on nectar, such as hummingbirds, also need to leave as the flowers fade. If they didn’t, they would starve.

Those birds that remain here all winter are seed eaters mostly, though some also consume berries. There are those that prey on other birds or small mammals and those that survive eating carrion, but winter is a season of making do for many of the birds and animals that remain here through all seasons.

Migration is a movement between locations. Some movements are over very long distances and can cover several continents. Others are much shorter, maybe covering no more than a few hundred miles. The impulse to migrate seems instinctive and the timing of both the annual departures and arrivals of migrant birds is often predictable and historically repetitive.

We have many migratory birds here on Cape Cod, and beginning in mid-March there is a nearly constant influx of species culminating in May. This means we are about to experience the peak of the migration season.

For many, birds seem to simply appear and disappear seasonally. Back in the day people thought birds hibernated like some mammals. They couldn’t imagine that tiny feathered creatures could fly thousands of miles. It didn’t make sense to them. These days we understand more about the instinctual pull to relocate every spring and fall as well as the mechanics of migratory birds and animals.

Many birds come and go quietly. Often, they fly at night, accounting for the mystery that surrounded their movements for many years. Stand outside on a spring night and you may hear the birds moving overhead. It is an eerie sound, especially the first time you hear it, as it can seem like a muttering, not a clear communication. It is the sound of birds keeping in touch in the dark, letting each other know where they are as they make their way north.

On May mornings birdwatchers arise before the sun to see and hear what migrants may have appeared overnight. Treetops come alive with the sounds and sights of tiny birds foraging for food before they continue on north or settle in to nest.

Many of our nesting birds are only here for a few months, feeding voraciously, feeding and raising young, and then heading back to their winter grounds. These include the orioles, towhees, catbirds, scarlet tanagers, rose-breasted grosbeaks, some shorebirds like terns and various herons, and warblers, to name a few. Hawks also migrate, though we obviously have some year rounders here.

Birds are not the only migrants here. Whales, dolphins, and many species of fish also travel to and fro in our waters on a seasonal basis. Humpback whales head south each fall where they will live for months without feeding. Many females will give birth during this time and lead their babies back north in early spring where the food is abundant. This is when the herring are heading upstream in great numbers, something the whales are happy to take advantage of. Right whales, which consume plankton rather than fish, are in our waters in late winter and very early spring but migrate north for the summer.

Striped bass, mackerel, bluefish, and even great white sharks migrate in spring and fall. As our waters warm due to climate change, we are seeing more species of tropical fish in our waters as well. We are also seeing more sea turtles here in the summer, some of whom get stranded on our beaches each fall due to plummeting ocean temperatures.

A few butterfly species also migrate, the most famous being the monarch butterflies. Even some dragonflies migrate, something you can see most easily in the fall when the big green darners gather over fields in impressive numbers.

May is a great time to get outside and enjoy our native wildflowers, the abundance of turtles, frogs, and other small creatures. If you’re lucky you may spy a family of foxes frolicking on the marsh or share a moment with a family of ducks as they make their way to a pond.

It’s time for the hummingbird and oriole feeders to go up, for the bird baths to be cleaned and readied for summer if they’re not out already. Maybe consider adding some native shrubs or plants to your gardens or yards that provide food for birds and pollinators, especially those that have berries.

No matter how sophisticated or cool we humans think we may be, it’s difficult to imagine the power and energy demanded of these small bundles of muscle and feathers that travel from South America to here and back in just a few weeks, sometimes even a few days. Migration isn’t without a multitude of perils, especially in our modern world filled with man-made obstacles, such as too much light, which distracts and disorients, tall reflective buildings to smash into, constant noise interfering with communication, and habitat destruction.

When you see a tern or an oriole or an osprey this summer, give it a nod. It has done something none of us can ever do. It has arrived on a wing and a prayer and pure guts. It’s a tiny miracle, really, and yet so common we often forget the effort and perseverance it represents.