Audubon’s Pewee

It’s a day in late May and already the nests of our eastern phoebes are bursting with nestlings preparing to fledge. Over the 47 years we have lived on our mountain, our buildings have hosted many eastern phoebe nests.

A phoebe in Plummer’s Hollow

A phoebe in Plummer’s Hollow (Photo by Dave Bonta in Flickr)

Some buildings, such as the guesthouse portico and the old outhouse, contained nests for several decades, but the outhouse finally collapsed and the phoebes deserted the guesthouse portico after years of successful fledgings. They continue to use either the outside or inside of the small springhouse, while the barn overhang has become a more recent popular nesting place.

Still, there has never been a year when phoebes have not used the top of a veranda column and one of the garage beams to raise families, even though we tried to discourage the veranda column nest sites when we had it repaired and painted by blocking in the flattened tops of the columns. Undeterred, phoebes molded their nests around the obstructions.

Eastern phoebes have been building their nests on human homes and outbuildings for centuries and were known in the 19th century as “barn pewees” as well as “bridge pewees” because they also favor the undersides of bridges. Before the advent of human dwellings and even today, they will build nests in natural rock outcroppings. All such choices protect their nestlings from the weather and often predators as well.

The Eastern phoebe (Sayornis phoebe)

The Eastern phoebe (Sayornis phoebe) (Photo by Soerfm in Wikimedia, Creative Commons license)

Members of the Tyrant Flycatcher family, eastern phoebes follow the first flush of insects north from their winter homes in the southern United States, Texas, and Mexico, often arriving in Pennsylvania in early March and leaving in late October. Sometimes they must survive late spring snow storms and are able to subsist on small fruits instead of insects until the weather improves.

These gray-brown birds with off-white throats and bellies are the first songbirds to arrive on our mountain around March 15. When I hear the raspy “fee-bee” of a male phoebe and see this tail-flicking flycatcher on a wire near the barn catching insects from the sunny side of the building, I know that spring is here.

In scientific circles, eastern phoebes are known as “suboscine” birds because their songs are innate instead of learned like those of “oscine” birds such as wood thrushes. But lately bioacoustic studies of their songs detected variations among male song characteristics that are not obvious to our ears but are to those of the birds.

John James Audubon’s house at Mill Grove

John James Audubon’s house at Mill Grove (Photo by Dennis on Flickr, Creative Commons license)

Eastern phoebes should be credited with first arousing bird artist John James Audubon’s interest in birds. When he was a youth, he lived at Mill Grove on the Perkiomen Creek in Chester County. Early in the spring of 1804, he found the empty nest of the bird he called “Pewee” or “Pewit flycatchier,” fastened to a rock in a cave on his property.

When the cave phoebes returned, he spent many hours watching them as they went about their phoebe business. “Before a week had elapsed,” he wrote in his Ornithological Biography, “the Pewees and myself were quite on terms of intimacy.”

Beginning on the tenth of April, he watched them repair their old nest as “they brought fresh materials, lined the nest anew, and made it warm by adding a few soft feathers of the Common Goose which were strewn along the edge of the creek water.”

Four eastern phoebe chicks in their nest

Four eastern phoebe chicks in their nest (Photo by jeffreyw on Flickr, Creative Commons license)

Even today, eastern phoebes often refurbish old nests instead of building new ones, since building a new nest takes five to 14 days and refurbishing an old one four days or less. One recent study found that new nest builders finished their first clutches later, were less likely to raise a second family, and lost their nesting attempts more often because of fallen nest structures, all of which led to “lower seasonal reproductive effort,” the scientists concluded.

Audubon’s close observations of phoebes’ family life reminded me of the time I spent watching a guesthouse portico family back in the early 1980s. The female refurbished an old nest and she then laid five white eggs.

The Guest House portico where I watched a phoebe nest; the arrow points to the location of a bat which also chose to nest under the roof another time

The Guest House portico where I watched a phoebe nest; the arrow points to the location of a bat which also chose to hide under the roof another time (Photo by Dave Bonta on Flickr

I sat inside the front door of the guesthouse and watched the family through the portico window, but I also climbed up on a chair outside and held a mirror above the nest to check the eggs. The female is the sole incubator, even sleeping in the nest overnight. It takes 16 days until the eggs hatch, and most eggs in a single nest, including the ones I watched, hatch within 24 hours.

Audubon’s eggs hatched on the thirteenth day and in his nest of six eggs one did not hatch just as in the nest of five that I watched one never hatched. In both cases a parent removed the egg. Audubon opened the rejected egg and “found the embryo of a bird partly dried up, with its vertebrae attached to the shell…”

Since the hatchlings are helpless, almost naked, and in need of nearly constant brooding, I waited until they were 11 days old, fully feathered, and active before spending an hour every day watching the nest and recording the number of feedings. For four days they averaged 25 feedings, but when they reached 16 days of age, the feedings diminished to 15 an hour. A recent study showed that parents adjust their feeding rates according to the begging rates of their nestlings.

By then the nestlings were flexing their wings or standing on the edge of the nest and beating them. When they were 17 days old, the female parent appeared with nesting materials in her beak and, despite screams of hunger from the nestlings, proceeded to build a second nest beside the first one, yanking nesting materials from the side and top of the first nest as the youngsters watched.

While she worked on construction, the male fed the nestlings. But sometimes when they begged, she tried to push construction materials down their throats which they promptly spat out. They even jumped back and forth between the old and new nests but settled into the old nest by nightfall. The following morning, at 9:30 a.m., they all fledged at once. Usually though phoebes fledge one at a time over an hour or so as the veranda column nestlings do.

Audubon’s painting of the eastern phoebe, the “pewit flycatcher” as he called it

Audubon’s painting of the eastern phoebe, the “pewit flycatcher” as he called it (Image in the Wikimedia, in the public domain)

While I kept a “hands off” approach to the young, Audubon spent his time gaining the trust of both parents and nestlings so that they tolerated the light silver thread he fastened to the leg of each nestling before they fledged. This was the first time that birds had been banded in North America.

His banding proved the following year that phoebes return to their same nesting site and even nest, writing, “When the Pewees returned to Pennsylvania I had the satisfaction of observing them again, in and about the cave. There again in the very same nest two broods were raised…Several of these birds which I caught on the nest had the little banding ring on the leg…”

He assumed many of the pairs he observed, not only in the cave, but on farm buildings and his mill nearby remained faithful during one breeding season and from year to year. Recently, two studies found that most pairs were both socially and genetically monogamous within a breeding season. In one case in Indiana only 15 of 87 families had extra-pair young in at least one brood, most commonly the second brood.

Those researchers followed up with a second study in which they captured and color-banded 198 males and 237 females, studied them for three seasons, and discovered that they were faithful to their territories, nest sites, and mates within and between years with 85.5% of males and 92% of females mating with the same mate during multiple breeding attempts. But mates were replaced following their disappearance and probable deaths.

A study of infanticide in Kentucky by an unrelated male phoebe even while the female continued feeding her nestlings, resulted in the death of all the nestlings. The researchers hypothesized that the male parent of the nestlings had died or disappeared and that it was a way for a non-breeding male to obtain a mate and start his own family.

A phoebe nest with a brown-headed cowbird egg

A phoebe nest with a brown-headed cowbird egg (Photo by Galawebdesign in Wikimedia, Creative Commons license)

A greater threat to breeding phoebes has been repeated brood parasitism by brown-headed cowbirds. I’ve occasionally observed cowbird parasitism in our nests over the years, but never in the veranda column nests. A study of cowbird parasitism in New York State concluded that even over generations of birds, cowbirds prefer particular eastern phoebe sites, such as our old outhouse.

Other threats to phoebe eggs and nestlings are black rat snakes, raccoons, coyotes, blue jays, American crows, chipmunks, and house wrens, but not one of those predators has climbed or flown into the veranda column nests.

Overall, phoebes are incredibly successful throughout their range including Pennsylvania where they live everywhere except for the urban cores of Philadelphia and Pittsburgh. Although our songbird population has dwindled since the 1970s, it is comforting to know that eastern phoebes continue to thrive and are able to quickly adapt manmade structures for their own purposes.

 

Chasing Breeding Birds

“You know you’re getting old when you start repeating yourself,” I thought when I first heard about Pennsylvania’s Second Breeding Bird Atlas project.

“Been there, done that,” I said and immediately signed up last spring and became the “owner” of the two blocks that include our property. The same, yet different, is probably an apt description of the present effort. Instead of relying on paper reports of the breeding birds we observe in our blocks, we claim our blocks and send in our reports via the computer, although folks without access to the internet can still participate the “old-fashioned” way.

Having previously discovered that sending reports in electronically for Project Feederwatch was much easier than filling in the charts they sent by snail mail, I figured that it would be just as easy to do the same for my atlas records. Well, it wasn’t. For several months, I was so frustrated that I didn’t even try after my initial repeated rejection by the program. It turns out that other frustrated participants and the people in charge of the program more or less served as guinea pigs, and when I finally took a deep breath and tried again, with the help of my husband Bruce, it worked. This year should be a breeze now that I’ve conquered the electronic bogeyman.

The line between my two blocks runs across the top of First Field directly below the spruce grove so every time I took a walk, I kept two lists of the birds I heard and saw. My home block is 61c65. It includes the hollow, the former clearcut, and a fair portion of both Sapsucker and Laurel ridges. What I call the Far Field block–61c56–takes in the spruce grove, the road to the Far Field, the Far Field itself and beyond. These blocks are large, and I can’t hope to completely cover them, but anyone who makes observations in my blocks is also free to report them either electronically or to the Project Coordinator Robert S. Mulvihill at the Powdermill Nature Reserve.

The seventeen breeding codes for the Second Pennsylvania Breeding Bird Atlas are similar to those of the first atlas, and I had no trouble using them. For instance, “X” means “possible,” and is defined as “an individual of a species seen or heard in suitable nesting habitat within safe dates, but not exhibiting any of the breeding behaviors described in” the other categories.

Initially, all my bird observations fell into the “possible” category–69 species in my home block (officially Tyrone 5) and 43 species in the Far Field block (officially Tipton 6). Many remained there throughout the season, but day by day some of the “possibles” became “probables” and even “confirmed” breeding birds.

Because I know my territory well, walk the trails every day, and have, over the years, learned the songs and calls of all the birds that live here, compiling the “probables” was easy. Confirming them was harder because I had to see an adult bird carrying nesting material, food, or fecal sac, observe nest-building, watch a distraction display such as a ruffed grouse feigning an injury, find a recently fledged young, or a nest with eggs or young, or see an adult feeding fledged young. All such discoveries were serendipitous as far as I was concerned.

Yard birds in my home block were particularly easy. One family of eastern phoebes plastered their nest beneath the eaves of our springhouse and another built theirs on top of one of the porticos on our veranda. The springhouse nest, filled with five eggs, was a source of wonder to our four-year-old great niece Morgan visiting from New Jersey. Later, when our nephew Patrick visited, that same nest contained four young phoebes and a huge young cowbird. The cowbird fluttered off the nest and on to the ground when Patrick appeared. He was distressed and wanted to return it to the nest, but I explained to him that it would take more than its share of food from its unwitting foster parents and deprive its foster siblings of food. Nevertheless, we later found that it was strong enough to fly back into the nest. Still, those phoebes did fledge successfully on June 1.

The veranda phoebe nest allowed our visiting granddaughter Eva to watch the parents feeding the young from our upstairs hall window. That family also fledged successfully.

During Eva’s visit in late May and early June, she and our son Dave also discovered an eastern towhee nest with eggs in a barberry bush, and she and our son Steve discovered a turkey sitting on her nest at the base of a beech tree near our road.

Best of all, from Eva’s point of view, was the last walk we took before she went home to Mississippi. As we started down First Field, a hen turkey jumped up from the tall grass a couple feet in front of Eva. She was so startled she screamed and saw one week-old chick run. The mother hen, clucking loudly, walked slowly away, and Eva, entranced by her seeming tameness, followed her on to the Laurel Ridge Trail. Eventually, I persuaded her to leave so the mother could return to her hidden chicks.

I made my own discoveries almost every day in May, June, and early July. On May 16, I stopped to rest on a log beside Greenbrier Trail and was continually scolded by a female hooded warbler. After a while she “showed” me her nest. She landed on it, inside a barberry hedge, moved around, and then flew off. I checked it and found no eggs, but on June 2 she was sitting tightly on it.

Another bird that “showed” me her nest was the Acadian flycatcher. As I walked up the road that same June 2, an Acadian flycatcher scolded. Knowing that they often like to build their nests near the tip of a beech tree limb, I scanned all the small beech trees and couldn’t see a nest. It turned out to be suspended from the branch of a witch hazel tree overhanging the road.

One bird that did not show me its nest was the sharp-shinned hawk. Yet I suspected, as early as April 22 when a sharpie flew out from the Norway spruce grove, landed nearby, and emitted its high-pitched “creer-creer” call, that a pair was nesting there. Still, I played a cat-and-mouse game, mostly with the male, throughout the spring.

But on July 6, as I approached the grove, the male flew out, landed in a nearby black locust tree, and called “creer-creer-creer.” Then, the female suddenly flew from the vicinity where I thought I had found a nest back in May. She too called but disappeared over the hill while the male continued “creering” and flying above me.

Sharpies are so secretive during nesting that little is known of their nesting life. I never saw a sign of life in what I though was their nest built in a dense, double-spired spruce tree. Yet every time I approached the spruce grove, the male would either fly out and call or he would be sitting on the same black locust tree limb at the back of the grove. This spot provided a view of all possible predators including the female red-tailed hawk I saw him chase away on June 6. He looked like the proverbial bee chasing a bear, but even though she seemed to shrug off his repeated diving, she eventually disappeared over Laurel Ridge.

Finally, on July 9, I had my proof. The male sharpie flew over and called as I emerged on the far side of the spruce grove. I heard another, lower pitched call, coming from the deciduous forest near the grove, and then an immature sharpie landed and called “wheep-wheep-wheep” directly above me.

Throughout the month I heard and often saw young sharpies crying “wheep-wheep-wheep” and their parents answering “kik-kik-kik.” Sometimes they flew and called on the ridges and even near our house. The “wheeping” calls of the young sharpies continued into mid-August and several times I saw two together. There may have been more–sharpies average four to five young–but I never saw them.

Although the sharpie nesting was the highlight of my 2004 Breeding Bird Atlas “work,” I did have other exciting confirmations. On June 20, in the late afternoon, cedar waxwings flew continuously to one black walnut tree branch, half-hidden by leaves, and then down into the yard. It looked as if they were gathering either food or nesting material. In early evening, one flew down in front of me to gather something and then flew up to the tree branch where another waxwing was moving around. I thought I could see a nest on the branch, but I wasn’t certain.

Then, on July 13, while sitting on our veranda, I heard scolding calls and saw an adult cedar waxwing perched on our clothesline that repeatedly dove down into the tall grass. I rushed up to look and there sat a small, grayish-brown, cedar waxwing fledgling sporting a white stripe near its eye, a tiny crest, and the yellow stripe on its tail. Both parents dove at me when I tried to pick it up and put it in shrubbery so I left them to solve their own problems.

In addition to the young cedar waxwing, I also saw an adult American kestrel with two immatures perched on our electric wire and a fledgling Carolina wren in our lilac bush.

Baltimore orioles suspended their nest from a black walnut branch that overhangs our driveway; black-capped chickadees nested in an old fencepost near the barn; and gray catbirds built their nest in a thicket of forsythia. I watched a black-throated green warbler gather nesting materials along Greenbrier Trail, a field sparrow doing the same in First Field, and a female wood thrush, accompanied by a male, collecting dead leaves and dried grasses for a late nesting on July 6.

Several birds also performed distraction displays. Along Black Gum Trail one morning, I heard scolding and walked off the trail and “pished.” A blue-headed vireo dove at my head and barely missed me. I couldn’t find the nest but as soon as I walked away he resumed his singing. A histrionic ovenbird blundered around in the underbrush as if it was drunk, bumping into shrubs, and then flew up and down. A Louisiana waterthrush, beside our stream, a worm-eating warbler on the Black Gum Trail, and a brown thrasher, at the edge of the woods, also distraction displayed.

I even managed to watch birds gathering food for their young. Most notable were a male scarlet tanager at the edge of the Far Field Road and a yellow-billed cuckoo at the edge of the Far Field.

I had my disappointments though. A cerulean warbler sang in our yard, as one had the previous year, throughout June. So too did one at the Far Field. Yet they remained on the “possible” list. I would like to have confirmed them because they are, along with several other species I confirmed in my blocks–Louisiana waterthrush, black-throated green warbler, sharp-shinned hawk, wood thrush, and worm-eating warbler–of “general conservation interest” to the Atlas. None of my birds made the higher categories–“regional rarity” or “statewide rarity.” In past years we have had at least two “regional rarities” nesting here–golden-crowned kinglet and winter wren–but not last year.

Still, the quest for breeding birds adds a lot of interest to my daily walks in late spring and early summer and makes me more aware of what is going on in the avian world. And there is always the chance that I’ll discover some of those rarities.