For the past several weeks I've been witnessing sights and sounds indicating that familiar friends are returning to our region. In spring, there will be many seasonal movements bringing birds back from warmer climates in search of a place to raise their young.

Migration is an occurrence that helps us say, "Spring is here!" Some claim the American robin as their harbinger of spring. However, red-wing blackbirds arrive even earlier, and are more of a marker of seasonal changes, especially as many robins now remain in Massachusetts all winter.

Several other "early birds" showed up in early April. Great blue herons, north-bound Canada geese and hooded mergansers have returned to seek out open water. American woodcocks and killdeer searched between patches of snow for food in the softening ground.

Turkey vultures use the warming air currents to soar over the greening earth.

The bluebirds, phoebes, and tree swallows have arrived too. The birds that return early in the season usually spend the winter in the southern United States. Because they are closer, they can get back to their summer homes more quickly than the neo-tropical migrants who are in Central or South America.

The wood warblers, shorebirds and other long distance travelers are returning now, in mid-May or later.

Welcoming various species of birds back is like watching different marching bands and floats pass by in a parade. Each one adds its own music or flare in a specific order of appearance. They fill the fresh spring air with cheery songs and color and are a key reason why I love this time of year.

However, most of the magic of migration which I've experienced in the past has been the result of the movement, not in observing the actual movement. I welcome the birds back or in the autumn notice when they have left. Only in a few instances, such as during a fall hawk watch or when a skein of geese fly over, have I seen the act of migrating.

Perhaps that is why witnessing one of the most incredible migrations of the entire animal kingdom left me in sheer awe and amazement.

This winter, I was fortunate to have been given the gift of a trip to the east African country of Tanzania. This part of the world is home to the common wildebeest or gnu, a large bearded antelope with horns like a cow, a face like a moose, body like a buffalo and a tail like a horse.

There are more than 1 million wildebeest on the Serengeti plains of Tanzania and Kenya. Because of their constant need for fresh food and water, they are always on the move. Their migration never stops, and they make up to a 1,000-mile circuit each year. The pace of their movement and how long they stay in a particular area is completely dependant on rainfall, which stimulates the growth of the grasses on which they feed.

Along the way, they encounter lions, hyenas and dangerous river crossings with lurking crocodiles. The calves are born along the way and are able to stand and follow their mothers less than an hour after they are born.

The wildebeest herds, together with hundreds of thousands of zebras and gazelles, make up the world's largest remaining aggregation of land mammals. They fill the savanna from one horizon to the next, and appear like a great flowing river. The migration is a wonder to behold.

Yet, having witnessed the pounding hooves and straining muscles of one of the greatest migrations on the planet does not diminish my admiration for the eastern phoebe as it returns to build its nest on my porch overhang. Nor do I have less respect for the hermit thrush when his ethereal song rings again from the woods behind my house, announcing his safe return. Each of these encounters with wild creatures, whether in my own yard or halfway across the globe, reminds me what an incredible planet we live on.

Enjoy the coming of spring with all the movement and beauty that your corner of the world has to offer.

Birding in the Berkshires

What: Guided Bird Walk  to look for migrant birds,  especially wood-warblers, with Noreen Mole, past president of Hoffmann Bird Club

When: 7 a.m. Friday

Where: Canoe Meadows Wildlife Sanctuary, Holmes Road, Pittsfield.

Admission: $3, bring binocuars, beginners welcome

Information: berkshires@massaudubon.org

What: Hoffmann Bird Club Morning walk in search
of spring migrants and rails

When: 7 a.m. Sunday

Where: Meet Price Chopper parking lot, Pittsfield-Lenox Road, Lenox

Information: Gael Hurley (413) 281-1017.