PASTURE FLYCATCHERS

     Southeastern Pennsylvania farmland has many cow pastures of short grass, and a few tall trees that shade livestock.  Many of those meadows have a stream running through them, which waters the stock.

     Several kinds of birds nest in those meadows, including three kinds of flycatchers, including eastern kingbirds, willow flycatchers and eastern phoebes.  Each of these species of flycatchers, however, has its own niche, which allows the three kinds the opportunity to nest in the same pastures, with little competition for food and space among their relatives.

     All species of flycatchers use their beaks to snare flying insects in mid-air, which gives them their common names.  Each individual of all species flutters out, grabs an insect and zips back to its perch to ingest its meal and watch for another victim and another.

     Because flying insects are not available in North America in winter, almost all flycatchers migrate south to Central and South America, where flying insects are still for the taking.  Only a few eastern phoebes stay north during winter, if they can find a warmer microclimate in sunny thickets near water.  Sunlight and warmth coming off water helps keep a few insects active during part of many winter days.   

     Eastern kingbirds raise young in open, short-grass pastures, each with a few trees scattered here and there.  Each pair of kingbirds places its twig and grass cradle among twigs in one of those trees.  

     Kingbirds are black on top and white below, with a white band on the end of their black tails, which helps identify them.  They utter a sputtering song and have a quivering flight on shallow wing beats.  

     Willow flycatchers nest in thickets of shrubs, vines and young trees where their little nurseries are well hidden.  This species is a dull, brownish-gray all over, which camouflages them well in thickets.  Males repeatedly sing an explosive "fitz-bew", which gives away their presence and identifies them.

     Eastern phoebes in meadows is a surprise because this species is a woodland flycatcher.  They traditionally hatch offspring on rock ledges, under overhanging boulders near water in woodlands.  But these adaptable flycatchers have adapted to nesting on support beams under bridges and porches in woods.  And they adjusted to rearing young under little bridges surrounded by thickets in pastures.  

     Phoebes are plain brownish-gray all over, which hides them among the shadowy woods and thickets  they nest in.  Male phoebes sing an oft-repeated "fee-bee, fee-bee", which again gives away their presence and identifies them.  But, as with all song birds, phoebes sing to establish nesting territory,  attract a mate for raising young, and repel other males of their own kind.

     These kinds of flycatchers adapted to nesting in southeastern Pennsylvania cow pastures, but each  in a different niche, which lowers competition for food and space among them.  They all have increased their populations by adjusting to rearing offspring in human-made habitats, as well as in natural ones.  Adapting is a key to success.           

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