The shortening days of late summer and autumn trigger the leaves of our deciduous trees to begin preparing for winter. As the water supply is cut off to the leaves the green pigment chlorophyll dies first and the remaining pigments give us the beautiful colors.

Well, autumn signals changes for our birds, too. With leaves dying, and nothing for caterpillars to feed on, the warblers, vireos and tanagers head south. The cooler fall temperatures, and eventually freezing temperatures, also kill most of the flying insects.

I enjoy the birds of summer (not the heat and humidity) and it is sad to see warblers, and especially the wide variety of flycatchers, leave for warmer climes.

The hardiest of the flycatchers, the Eastern phoebe, hangs around the longest, often until mid-October. It is also the first to arrive back here. Sometimes they arrive before the last “onion snow.” This year my first Times News area sighting was March 29. Most years I see the first hardy one here about March 15-17.

They are also the first of the flycatchers to nest, and two weeks ago I spent an hour watching a female phoebe make numerous trips back and forth to her nest. Phoebes have adapted quite well to humans; well, actually their structures. They often nest under bridges, atop a window frame of a hunting cabin or under roof eaves. I, within a few miles, know where at least a dozen pairs are nesting now.

Flycatchers, except maybe for the Eastern kingbird, are rather difficult to identify. Members of the Empidonax family are best identified by their songs. The empids (for short) that breed in this region are the willow flycatcher, Acadian flycatcher, least flycatcher and the alder flycatcher.

Another hint in identification is their choice of habitats. I generally find willow flycatchers in areas of which their name implies. I have a favorite birding spot along Lizard Creek near German’s bridge where a wet/damp meadow is dappled with willows and shrubs. Their fitzbew, fitzbew song alerts me that they have returned.

The Eastern pewee is a forest bird, and I locate most of them in the white oak woodlands in and around the Bethlehem Water Authority reservoirs. The pewee got its name from its soft peee-weee song. It is rather distinctive.

As with many of our birds that travel to Central and South America, their populations are declining. On a walk last June in Penn Forest Township, I noted how quiet the woods had become.

Olive-sided flycatchers, like the others, sing mostly in the spring months, with their singing tapering off in late July. They have a unique song and rather loud for its size; some may relate well to this song: quick-three-beers, quick-three-beers. No other song bird song is even close. Unfortunately, their numbers have dropped, and it is now rare to see or hear one.

I’ve found more Olive-sided flycatchers in late summer, characteristically perched atop the highest limb on a dying or dead tree.

Kingbirds, with their white-tipped tails, characteristically perch on a lower branch, dash out to snag an insect and then return to the same perch. They are the second largest of our flycatchers, with only the great-crested flycatcher about a half-inch larger.

Maybe those few hints will help you find some of the nine flycatcher species I have seen in Carbon County. So, beginning the first week of May, listen and look for one or most of our flycatchers.

Test Your Outdoor Knowledge: This great-crested flycatcher has a beak full of nesting materials. What else besides mosses does it typically include in its nesting cavity? A. abandoned snail shell; B. hemlock cones; C. shed snake skin; D. pieces of a Phillies pennant.

Last Week’s Trivia Answer: The beautiful pintail duck does not breed in our local region.

Email Barry Reed at breed71@gmail.com