Millions of birds are on the move up and down the Atlantic coast. Spring migration is one of the largest seasonal natural history occurrences easily observed by individuals living in southern Maine. An estimated 3.5 billion birds migrate to the United States and Canada each year according to the Cornell Lab of Ornithology.

Red-winged blackbirds have already made their return to Maine, and are now being joined by other species like American woodcock in getting a jump on establishing their territory. Toby Talbot photo/Associated Press

Peak time for songbirds in our area is typically mid-May, although annual variation does occur based upon weather conditions. We live in the Atlantic flyway, one of four major flyways in North America. The others are the Mississippi, Central, and Pacific. Generally, many bird species making their way farther north will pass through states along the coast, with birds dispersing inland to occupy breeding territories.

The annual migration of birds is directly tied to the availability of food. Each spring birds make their way north to take advantage of the warmer weather and the appearance once again of insects and other invertebrates. Every fly, moth, beetle, or spider is a perfect protein package that is needed by birds for egg production and growth of the chicks. This phenomenon reaches its zenith in the Arctic, where the summer months result in hordes of insects and near 24-hour daylight feeding conditions.

Here in southern Maine some of our breeding birds have already arrived, such as Red-winged blackbirds and Eastern bluebirds. Other species are still making the journey. Yet other species will pass through the region on their way north to breeding grounds. An example is the Blackpoll warbler on its journey to the boreal forests of northern Canada and Alaska. Sightings of many of our most colorful birds are beginning with Baltimore orioles, Rose-breasted grosbeaks and numerous wood warblers being reported. Birders know the best time to see many of these birds are before the leaves are out, affording unobstructed views.

This is the time to put your boots on and find a nearby trail. Many birders will flock to popular spring destinations such as Evergreen Cemetery in Portland. The trail system at the back of the cemetery has dozens of birders on any given May weekend morning. Some of the most dazzling songbirds are on display, especially the wood warbler family with the males in their brightly colored plumage.

On a good day, over 20 species of warblers can be found. With luck you might see Magnolia, Yellow-rumped, Canada, Black-throated Green, Cape May, Blackburnian, Chestnut-sided, and Yellow warblers. We have other equally good, but less birded sites right here in Scarborough.

A few suggestions include Warren Woods, Fuller Farm and Pleasant Hill Preserves. Each location has a variety of habitats, increasing the diversity of bird species found. You can help our land management by sending bird lists from Scarborough Land Trust preserves to info@scarboroughlandtrust.org.

Knowing what species are present will help us with management practices for wildlife. Managed by the Cornell Lab of Ornithology, eBird (ebird.org), is an international on-line database of bird sightings. You can enter your data or check out recent sightings from others. Keep in mind a standard tenant about finding birds, they are most active early in the morning and again later in the day closer to sunset.

Small songbirds such as sparrows, warblers and vireos can be difficult to identify for novice birders. Fortunately, in Scarborough we have a fantastic alternative with Scarborough Marsh. This largest contiguous salt marsh in the state is summer home to many larger species of birds, such as: Great egrets, Snowy egrets, Glossy ibis, osprey, willet, and more.

The wide-open expanse of the marsh provides for easier observation with binoculars or a spotting scope. A good route through the marsh is the Eastern Trail. Another excellent birding area is our Blue Point Preserve off Seaveys Landing Road. This small preserve provides opportunities to watch both forest birds and marsh birds. Two observation points provide an overlook out to Scarborough Marsh. The marsh is tidal, so high or low tide can make a difference for marsh birds. Low tide will expose mud flats favored by shorebirds, such as willets and Greater yellowlegs.

Enjoy the spectacle of spring migration and the wonders of birding. Members of the Scarborough Land Trust staff are always happy to help answer questions and give advice on local trails and conditions. Call during normal business hours, 207-289-1199. Also, check out upcoming bird walks and other programs at http://scarboroughlandtrust.org.