Spring migration brings birds from afar | Field Notes

A redwing blackbird rests on a cattail.
A redwing blackbird rests on a cattail.
Photo courtesy of Gary Eduardo Perless
Posted

In colors the fields dress up in the Spring; 

In colors, are the little birds that come from afar...

translation of Mexican folk song,
“De Colores”

The merry month of May brings an invigorating combination of sun, showers, colorful flowers, and singing birds coming from afar. Hurray for May! 

While humans are busy tidying up from the winter storms, getting gardens ready for planting, and excitedly pulling out their colorful spring clothes, the birds are focused on mating and raising the next generation. After a long winter, the exuberant songs and colors of birds can raise our spirits, but there’s an important purpose behind the song and dance: It seems that the female birds choose to mate with the more brightly-colored, ostentatious males who sing well and vigorously defend their territory. 

For humans, spring is a lovely season of sights and sounds, but the life of a bird is fraught with dangers; predators ranging from crows to cats, window collisions, toxic pesticides, and loss of habitat. Add in the risks of migrating long distances, and once the nesting area is reached, a bird is most vulnerable when sitting on its nest (not to mention flightless youngsters). 

(Near the end of this column, I’ll list some positive actions we can take to help birds.)

Every spring in the Northern Hemisphere, birds are pulled northward by the instinct to breed. Birds need to eat frequently to maintain their active lifestyle, and so migrating to buggy, swampy places to breed and raise young is a proven strategy — thus, spring migration! By mid-May, the peak of spring migration, millions of birds are winging it northward. They know to follow the ancient flyways of their ancestors, frequenting customary rest stops en route to breeding grounds. To conserve precious energy, they wait for a change in the weather, to ride the tailwind.

Scientists are still unraveling the mysteries of how birds navigate this hazardous journey. We know that birds are guided by instinct, as well as the moon and the apparent rotation of the stars. Birds’ eyes have cells activated by the Earth’s magnetic field, pointing the flock northward like a compass needle (magnetic north, I suppose!).

One recent discovery — using radar technology to track flocks of birds — shows that many birds travel at night! Songbirds like Swainson’s Thrush, Black-headed Grosbeak, waterfowl like Red-breasted Merganser, and many more species join in this fly-by-night journey. 

They usually start migrating in the first hour after sunset, and the nightly movement peaks a few hours later. Using the website, birdcast.info I was able to find out that, on a recent night, between 9 p.m. and 6 a.m., an estimated 343,700 birds passed over Jefferson County! (Here’s the link: dashboard.birdcast.info/region/US-WA-031.)

Birds actually have two brains, each able to rest independently, so they can sleep one side of their brain while using the other to fly! Another hazard is light pollution: Songbirds migrating at night are attracted to bright areas, causing them to go off course, burn extra energy, and increase their risk of colliding with buildings or being caught by predators. This is why it is important to direct outdoor lighting downward, shield the light, or just turn it off at night.

Each year, in the month of May, bird lovers celebrate World Migratory Bird Day. This year’s theme is, “Dim the Lights for Birds at Night.” Go to the website to learn more.

My own migrations, for work, have taken me eastward, across the Cascade Mountains, to Sandpoint, Idaho; a gem of a small town that shares much with Port Townsend — mountains and forests, shorelines and historical tourism, local breweries and music festivals, and an abundance of birds. I’ll continue taking note of the changing bird populations — the departures and arrivals — which, for me, makes tangible the change of the seasons. Happy spring!

Some positive actions we can take to help birds:

Landscape with plants that attract insects or provide berries for birds.

Keep your cats indoors, or at least keep them away from nesting birds or feeders.

Avoid toxic garden sprays that persist in the food chain.

Leave hedgerows, brush piles, and a diversity of shrubs for birds to hide in.

Put out bird baths, water dishes, or create a pond.

Turn off outside lights at night, face lights downward, and pull the blinds to keep it dark outside.

To learn more about migration, click on the links below:

World Migratory Bird Day: worldmigratorybirdday.org.

How To Use the Birdcast Dashboard To See Your Local Migration In Detail: allaboutbirds.org/news/heres-how-to-use-the-new-migration-forecast-tools-from-birdcast.

(Gary Eduardo Perless is the education director with Admiralty Audubon Society. Contact him at gperless@gmail.com.)