Yellow warbler. (Andy Reago and Chrissy McClarren)

As the days grow longer, a mass migration of millions of birds is set in motion. Three hundred and fifty different types of birds, many from the tropics, move into North America to find mates and raise their young.

The Western Maine Mountains are the destination for a large number of these birds and have led some to refer to our region as a “baby bird factory.” April is a good time to prepare for the arrival of these visitors from away. Clean out your bird boxes and feeders, and brush up on their songs and field markings. May and June are just around the corner, and we are about to be invaded.

Early arrivals include American woodcock and yellow-bellied sapsucker. In fact, these birds, along with some ducks and mergansers, have already moved into our area. Soon, Maine’s state bird, the common loon, will move from the coastal waters to our lakes and ponds. Great blue herons and turkey vultures, along with a number of different hawks, are among the larger, more visible visitors that will move in. Watch for chimney swifts, barn swallows and tree swallows, who will soon be swooping over fields and yards eating insects by the pound.

However, a host of other birds sneak into our area. Many thousands migrate at night and dissolve into the woods and marshes, often before they are noticed. Tropical warblers, the color of jewels in yellow, blue, orange and green, are small and blend in completely once trees have leafed out.

These include black-throated blue, chestnut-sided, and yellow warblers (photo by Andy Reago and Chrissy McClarren), along with the common yellow-throat, and can be found on almost any visit to Valentine Farm Conservation Center. A little later, toward June, we will host rose-breasted grosbeaks, scarlet tanagers and indigo buntings. If you don’t know these birds, look them up and you will be amazed that such bright colors are flitting in the woods around you.

If you are interested in learning more about these birds from away, join Mahoosuc Land Trust on Saturday, April 20, to observe the courtship flights of the American woodcock. Also, the second in the Beginner Birder Series will be held Friday, May 3, from 6 to 8 p.m. at the Valentine Farm Conservation Center. The focus will be migrating birds. The following morning, May 4, a walk will be held to catch a glimpse of these colorful birds from away.

James Reddoch, of Albany Township and Boston, leads birding events for the Mahoosuc Land Trust which celebrates 30 years conserving the natural areas of the Mahoosuc Region. Visit Mahoosuc Land Trust at 162 North Rd., Bethel, or at www.mahoosuc.org. To learn about events or to contact James, email info@mahoosuc.org.