It happens every spring and fall. Millions of birds of hundreds of different species take part. They respond to cues mostly too subtle for humans to notice, and follow ancient pathways that are invisible to our eyes. Their journey may simply take them from a high alpine meadow to the lowlands a few miles away, or it may take them several thousand miles from boreal forest in the far north to tropical rainforest near the equator. They move to take advantage of seasonal abundance. In spring, birds travel to suitable areas in which to raise their young, and in fall they make their way back to places in which to pass the winter with the next generation in tow. The route is learned by the young ones, and the cycle of migration continues.
With a diversity of habitats and relatively mild winters, Western Washington provides both summer breeding areas and over-wintering sites for a wide array of migratory birds. Some birds migrate within the state, such as the Varied Thrush which moves from higher elevations to low lying areas as winter approaches. Other birds such as flycatchers, swallows, and swifts raise their families in our state during the summer, but fly south 2,500 miles or more to pass the winter months in Mexico, and Central and South America. Snow Geese and swans spend the winter months in Washington, but head north to Canada and Alaska in the spring. Some birds even migrate along an east-west path, such as grebes and loons, who nest inland on freshwater lakes but over-winter in saltwater bays.
No matter how short or great the distance traveled, migration poses many challenges for birds. Migrants may be subjected to inclement weather, predators, potential starvation, even sheer exhaustion when traveling long distances. Although it has always been a risky business, human influences add a whole new dimension to the dangers of migration.
At PAWS, we work with a number of different long- and short-distance migratory species. The majority of them are brought in for care after they suffer injuries related to human activity. One of the most frequent causes of injury is birds flying into windows. Just the day before this article was written an Orange-crowned Warbler and a Fox Sparrow, both migratory species, arrived at PAWS after striking windows. Both birds were badly stunned, but fortunately did not have any broken bones, and were released after spending the night at the Wildlife Center. Many other migratory birds are not so lucky.
On the same day the Orange-crowned Warbler and Fox Sparrow arrived, a Golden-crowned Sparrow, also a migrant, was admitted to PAWS Wildlife Center for care. This bird had run into another common, human-created danger: he had been attacked by a domestic cat. Unfortunately, the bird had suffered a fractured spine in the cat’s jaws and was paralyzed. The only help PAWS wildlife staff could offer him was a release from pain through humane euthanasia.
In addition to cat attack and window-strike victims, PAWS receives a number of migratory birds who have been hit by cars. But even in the absence of vehicles, the roads themselves can pose a threat to migratory water birds. From the air, the reflection off the surface of wet pavement can look very much like the reflection off of a lake or river. During migration, PAWS frequently receives water birds who have injured themselves by crash-landing on wet pavement. With some species, such as loons and grebes, even if they avoid injury while landing, they become stranded. Their bodies are so specialized for an aquatic existence that they must "run" on the surface of water for long distances before they are able to get airborne. On solid ground they are essentially flightless.
The greatest threat to migratory birds is one that cannot be readily observed as a cause for admission at PAWS. For many species, habitat in both their breeding areas and over-wintering areas is quickly disappearing. Some have been able to adapt and take advantage of human-dominated landscapes. Barn Swallows, for instance, nest almost exclusively on buildings, bridges, and other man-made structures, and Vaux’s Swifts have found chimneys to be a suitable substitute for hollow, dead trees. But most species cannot cope with such rapid changes in their environment. As habitat continues to disappear their numbers steadily decrease.
So what can we do to make migration a little less challenging for birds on the move through our neighborhoods? We can start by addressing some of the dangers around our own homes.
Birds generally hit windows because they see surrounding vegetation reflected in them. Windows can be "bird-proofed" by hanging windsocks, strips of foil, or other objects in front of them to minimize reflections. You can also place bird netting over your windows in such a way that it prevents birds from impacting the glass. The netting should be stretched tight, and there should be at least three or four inches of space between the net and the glass to provide an effective barrier.
You can make your yard much safer for all birds—and other wildlife—by not allowing your cat to roam freely. More information on keeping both wildlife and your pets safe can be found on our Wildlife Resources page.
Possibly the best thing you can do for migratory birds is to give them back habitat. Replace green lawns and manicured ornamental plants with native vegetation, and encourage friends and neighbors to do the same. You will see the results of your work firsthand when flocks of migrants use your property as a stopover point. You will be amazed to discover the number and variety of birds that even a small patch of quality habitat will attract during migration and at other times of year.
None of the above suggestions to help our wild friends thrive requires much time, money, or effort to accomplish. In a world where many problems seem too large to ever overcome, it’s refreshing to know that just a few small steps can make a real difference to our wild neighbors. The best gift you can give to a wild animal is a place to call home.