Migrant Merlins

     I went to Chamber's Lake, which is a human-made impoundment in Chester County, Pennsylvania, for a few hours on October 3, 2016 to experience nature.  I saw overgrown fields of blooming goldenrod, tall grasses gone to seed, and patches of cattails and phragmites in low, moist places in the fields.  The lake was bordered on two sides by deciduous woods and its water level was down a little, exposing mud flats and gravel bars. 
     I saw some species of small birds in thickets on the edges of the impoundment.  They included permanent resident northern cardinals, song sparrows and northern mockingbirds, plus a few gray catbirds, a couple of eastern bluebirds, an American goldfinch and a migrant wood pewee, which is a kind of flycatcher.
     And I noticed a few pied-billed grebes, an osprey, an immature bald eagle, a great egret and up to a half dozen great blue herons around the lake.  These birds were there, in part, to catch fish, each species in its own way.  Grebes dive under water from the surface to snare small fish while egrets and herons wade the shallows after scaly prey.  Ospreys and eagles drop from the sky feet-first to catch larger fish in their curved, sharp talons.
     But what I didn't see, and thought I should have seen, were shorebirds.  I didn't see any on the flats or gravel bars at all.  And the reason for their absence was a few merlins perched on rocks on the bars.  Merlins are falcons in the hawk family and in the same genus as peregrine falcons.  Merlins specialize in eating small birds and large insects they grab in open habitats.  The mere presence of merlins on the flats at Chamber's Lake kept shorebirds off them.
     Merlins are intriguing hawks that are a bit smaller than rock pigeons.  Adult females and young are dark-brown on top and heavily streaked with brown below, which allows them to blend into their open, bare-ground habitats.  Adult males are slate-gray on top.  And all birds, young and older, male and female, have pointed wings and 22 to 25 inch wing spans for swift, powerful flight.
     Merlins raise four or five young in a brood in other birds' nests in deciduous or coniferous trees in clearings in spruce/fir forests.  They also rear offspring on cliff ledges, holes in banks and abandoned woodpecker hollows in trees along rivers and in park-like grasslands with scattered trees.  All those natural habitats extend across the northern part of the northern hemisphere, including most of Canada and Alaska.
     Merlins winter on beaches, mud flats, salt marshes, fields, golf courses and other open habitats along the Gulf Coast, and in Florida, the southwestern United States, Mexico, Central America and northwestern South America.  They patrol those habitats, natural and human-made, for shorebirds and small song birds.  And they often perch on a tree, rock or other elevation to watch for prey.
     These dark, nearly pigeon-sized falcons migrate across the entire United States, including here in southeastern Pennsylvania.  I see them here as migrants in October, and a few winter here, on a golf course with scattered trees, on a large lawn with a sprinkling of planted trees in a state park and in farmland harvested to the ground, for examples.  There they catch bluebirds, sparrows, horned larks and other kinds of small birds.           
     Merlins are exciting to see chasing small birds.  These slim, speedy falcons fly low and fast through open country, with quick, powerful wing beats, to overtake their panicky victims.  Because of their zip and aggression on the wing, merlins have been used in falconry.
     Since the ban on using DDT in the United States and merlins' adapting to human-made habitats, including cities, this falcon's population has increased significantly.  With a little looking in the right places at the right times, readers might see merlins in the future.  It's only a matter of getting out and waiting long enough.