Those Darn Empids

Keen birders are aware that the best time to identify the five small, look-alike Empidonax flycatchers that breed in Pennsylvania is in May when they are singing and calling during migration. Easier to identify by their voices than by their appearance, all empids, as birders call them, have gray heads, backs, wings, and tails, white wing-bars, light eye-rings, and whitish breasts and bellies with beige edges.

A willow flycatcher (Photo by Mark Bonta)

A willow flycatcher (Photo by Mark Bonta)

Over the nearly five decades we’ve lived on our Ridge and Valley mountain, I’ve heard four of the five empids, but I was thrilled last May 17, when our son, Mark, found a willow flycatcher singing from the old apple tree beside our driveway.

I rushed out to see and hear the bird as it flew into the top of a yard black walnut tree and sang—“fitz-bew,” “fitz-bew.” A half hour later it was in our backyard, where it clung to a tall grass and poked into our forsythia hedge, still singing. It stayed another day and then was gone.

Until 1972 willow flycatchers were lumped with alder flycatchers and called Traill’s flycatchers. Then ornithologists split the Traill’s into two species based on their songs. While willows sing a sneezy “fitz-bew,” the alders sing “tree-bee-a,” that sounds like “quick, three beers.” Although willows retain the species’ name traillii, alders are alnorum, meaning “of the alders.”

Willows breed across the northern two-thirds of the United States. Here in Pennsylvania they nest in brushy wetlands, wet meadows, and streamside thickets below 2300 feet. The females build compact cup nests several feet above ground in a forked branch of a shrub or small tree.

According to The Second Atlas of Breeding Birds in Pennsylvania (BBA2), there was a large increase in willows from the first Atlas of Breeding Birds in Pennsylvania (BBA1) that covered the years 1983-88, especially in the southeastern part of the state, the Ridge and Valley Province and the Northwestern Glaciated Plateau section but a decline in the southwestern corner of Pennsylvania.

With an estimated 135,000 singing males in the state, it seems as if willow flycatchers are thriving here and also in the disturbed habitat in Central America where they spend their winters.

An alder flycatcher on elderberry (Photo by Caleb Stemmons on Flickr, Creative Commons license)

An alder flycatcher on elderberry (Photo by Caleb Stemmons on Flickr, Creative Commons license)

Many Mays ago I walked past our small wetland below our guesthouse and heard an alder’s “quick, three beers.” I never did see the bird but it, like the willow, was migrating through our property on its way north. Last May 30, Mark briefly heard and saw one in black locust saplings on the edge of First Field at the base of the powerline right-of-way.

Alders have the northernmost breeding range of any empid—across sub-Arctic Canada and Alaska, south to Ohio and Pennsylvania and through the Appalachians to North Carolina and Tennessee. Usually alders breed at an elevation between 820 and 2300 feet in denser, wetter, and more wooded habitat than willows, such as alder bogs, shrub swamps, and even recovering clear-cuts, but sometimes in the same habitat as willows.

Unlike willows, northern Pennsylvania is the southern edge of the alders’ core breeding grounds in the glaciated sections of the Appalachian Plateau, most notably Erie and Crawford counties in the northwest, according to BBA2. With a whopping 161% increase from BBA1, and an estimated 28,000 singing males, this species also is thriving here, although the wooded wetland habitat it depends on needs to be protected from human changes in the landscape.

Alders build their nests near the ground in the upright fork of a shrub in June and sing in migration from the third week in May until the second week in June and on their breeding grounds as late as the second week in August, a week before the bulk of the population begins heading south to their wintering grounds in north and central South America.

A least flycatcher (Photo by Fyn Kynd on Flickr, Creative Commons license)

A least flycatcher (Photo by Fyn Kynd on Flickr, Creative Commons license)

Least flycatchers E. minimus sing an emphatic “che-beck” over and over, a song I hear most springs during their migration up from Mexico and Central America when they arrive on our mountain as early as April 15, but usually by the first week in May. Like the alders, northern Pennsylvania is the southernmost breeding range for leasts, except for those that move down the Appalachians to North Carolina and Tennessee.

Last May Mark recorded them singing in the barberry shrubs and small walnut saplings in First Field and from large oaks and tulip trees in the higher hollows beyond Dogwood Knoll, and I heard one on May 24 in the old apple tree behind the guesthouse. The previous summer (2019), they were still singing and Mark hypothesized that they may be breeding here occasionally.

Leasts breed in open deciduous and mixed forest, woodland edges, orchards, and wooded suburbs, and in a recent 2008 study, they nested close to each other, probably to help deter predators, attract females or both. Their deep, cup-shaped nests are on deciduous tree branches less than 20 feet high and have eggs in them in late May and early June.

According to BBA2, there were scattered breeding records from the Pittsburgh Low Plateau and Ridge and Valley Province, but most leasts breed across Pennsylvania’s northern highlands. Unfortunately, breeding was down 6.6% from BBA1, with an estimated 138,000 singing males.

An Acadian flycatcher (Photo by Kelly Colgan Azar on Flickr, Creative Commons license)

An Acadian flycatcher (Photo by Kelly Colgan Azar on Flickr, Creative Commons license)

Acadian flycatchers E. virescens are now the most common breeding empid in Pennsylvania. Their loud, explosive “pit-see” is unmistakable once you hear it. However, I’d been hearing it for several years in our north-facing hollow and thought it was an alarm call of another songbird. Then, on May 22, 1994, as I led a field trip along our hollow road for our Audubon group, Stan Kotala identified the caller as an Acadian flycatcher. Once I knew the caller, I also heard it in the large oaks where we built our exclosure in 2001.

On May 22, 1995, the first Acadian was back and singing and on June 12, as I walked our hollow road, an Acadian started scolding me. I followed it with my binoculars and saw it go to a nest hanging from the end of an American beech branch 70 feet from the ground. It was a new breeding species for our property and for Blair County and suited the description in BBA1 which stated that the Acadian flycatcher “inhabits woodlands near streams, where it frequently builds in the pendant branches of a beech…”

Acadian flycatcher babies in nest (Photo by Brian Henderson on Flickr, Creative Commons license)

Acadian flycatcher babies in nest (Photo by Brian Henderson on Flickr, Creative Commons license)

On July 5, while driving my Dodge truck, I asked our son Steve to climb out on to the truck bed and check the nest. He saw two fluffy young still in the nest as a distressed adult Acadian called. We quickly retreated and late in July examined the empty nest constructed mostly of hemlock twigs and spider webs.

According to BBA2, Acadians reestablished their range in Pennsylvania and other eastern states in the early 1900s after a long absence probably due to nineteenth century deforestation because Acadians breed in lowland areas in old-growth woodlands near streams especially narrow, hemlock-lined ravines. They prefer a closed canopy and an open-to-moderate understory, but further south they breed in deciduous forest and bald cypress groves.

Pennsylvania is near the northern limit of their population that ranges west to Nebraska and Texas, south to the Gulf coast and central Florida. They breed in most of south, central and northwestern Pennsylvania with a 30% increase from BBA1 to BBA2 and an estimated 149,000 singing males. By late July until the third week in September they begin migrating south to their wintering grounds in south Central America and northern South America.

A yellow-bellied flycatcher (Photo by Stan Lupo on Flickr, Creative Commons license)

A yellow-bellied flycatcher (Photo by Stan Lupo on Flickr, Creative Commons license)

The least common of the empids here are yellow-bellied flycatchers E. flaviventris. Breeding across Canada to southern Minnesota and Pennsylvania, these shy birds hide in dense thickets during migration and rarely sing. They breed at elevations from 1660-2250 feet in bogs and open swamps with sphagnum moss and scattered canopy deciduous and conifer trees and build nests on the ground on sphagnum hummocks hidden by shrubs or ferns. They sing “killink,” and call “chu-wee” from prominent perches.

Once thought to have left Pennsylvania after nesting in the Mt. Pocono area in the early twentieth century, in 1980 Douglas A. Gross found an adult yellow-bellied with young in a Sullivan County hemlock grove, the first confirmed nesting here in 42 years. They breed as early as May 24 but as late as June 20. The nest Gross first found fledged young on June 23 but the male continued feeding them until July 7. Later studies by Gross found that a few pairs are double-brooded with new nests as late as August 2.

Today a few breed mostly on North Mountain in Sullivan and western Wyoming counties and have been listed as Endangered by the Pennsylvania Game Commission and Pennsylvania Biological Survey.

Mark recorded what was incessant calling by a yellow-bellied that he saw below our Greenbrier Trail last May 20 in the early morning, proving that May is the premier month for hearing the songs and calls of those darn empids.

 

Woodcock Spring

Shortly before dark last February 10, our son Dave walked up the driveway and heard the “peenting” of an American woodcock. He raced up to our house to alert our son Mark and me, and we joined Dave on our veranda to listen.

A woodcock (Photo by Don on Flickr, Creative Commons license)

A woodcock (Photo by Don on Flickr, Creative Commons license)

A couple minutes passed before both sons said, “Listen.” That’s when I heard the whirr of the woodcock’s wings as he flew overhead. I also saw his distinctive, chunky silhouette. In the nearly 50 years we have lived on our west-central Pennsylvania mountaintop, we had never seen or heard a displaying American woodcock before March 15.

But last February was warmer than usual. After heavy rain the previous night, most of the snow had melted, and by evening it was 45 degrees. At least one male woodcock had migrated north early from his wintering grounds in the coastal lowlands from the Carolina’s south and west as far as Texas. Or, more likely, because the winter had been unusually mild, he may have come from almost any suitable habitat across the southern part of Pennsylvania, according to McWilliams and Brauning in The Birds of Pennsylvania.

February continued to be warmer than usual, and we recorded other early arrivals such as American robins, eastern bluebirds, field sparrows, eastern towhees and turkey vultures. But we neither saw nor heard any more woodcocks until March 18 when Mark spotted one in First Field in the dawn light. The following day Dave encountered a woodcock on First Field Trail next to the exclosure and that evening he heard several singing woodcocks.

I had been going outside off-and-on every evening for several days to listen for woodcocks and hadn’t heard any. But on March 20, at 7:40 pm, I finally scored. I could not believe the amount of twittering and peenting I heard, although by then it was too dark to see them spiraling high into the sky on their twittering wings and then plunging back to earth as they chirped and then resumed their peenting.

The next morning at dawn Mark counted at least six woodcocks singing up and down First Field. I couldn’t get outside until 9 am, but I was determined to see the woodcock Dave had flushed near the exclosure.

The trail was wet, but ahead of me about 40 feet near the beginning of the exclosure fence, I saw the woodcock. I froze, and he stopped too. Instead of flying, he turned his head to look at me and pumped his rear end. He even allowed me to raise my binoculars so I could study him more closely—his large, black eyes set high on his head for rearview binocular vision, his extremely long, thin, black bill, and his chunky, mottled gray and brown body that blended into the leaf duff. He didn’t move and neither did I in what I could only think of as a magical moment.

A barred owl (Photo by M.E. Sanseverino on Flickr, Creative Commons license)

A barred owl (Photo by M.E. Sanseverino on Flickr, Creative Commons license)

Finally, I lowered my binoculars and turned away. I had heard a barred owl call nearby and I was worried that the owl might be interested in eating the woodcock since owls and hawks prey on the adult birds.

But that had been the longest, closest look I’d ever had of what ornithologist Arthur Cleveland Bent called “this mysterious hermit of the alders, this recluse of the boggy thickets, this wood nymph of crepuscular habits.” Usually they fly before I spot them, but this one seemed almost tame. Since woodcocks often return to the same breeding grounds every year, maybe it was the same one I’d seen along this wet trail other springs and maybe it was a female instead of a male. Even though the females have slightly heavier bodies than the males—7.6 oz. to the male’s 6.2 oz.—and their bills are slightly longer, they look the same as the males do.

And the habitat for nesting was ideal—young upland woods near water and not too far from the males’ singing field. Males mate with multiple females and females often visit four or more singing grounds before nesting. Sometimes females continue doing so even while caring for young.

A nesting female woodcock (Photo by Andrew Hoffman on Flickr, Creative Commons license)

A nesting female woodcock (Photo by Andrew Hoffman on Flickr, Creative Commons license)

Three days later First Field Trail was soaked and muddy and the wetland inside the exclosure, where I flushed a sitting woodcock, was thoroughly drenched and puddled. So it was most likely that it was a nesting female.

In the dawn fog, five days later, as I hung out the birdfeeders, I heard a woodcock peenting in the flat area between the forest and the slope below our house. A second one joined in. I never did hear them fly, but I listened to dozens of peents before it was light enough to end their singing for the day.

The next morning Mark found a dead woodcock, with two blood spots on its bill, on Butterfly Loop in First Field. Although woodcocks are rarely aggressive, males sometimes chase each other above their singing grounds including performing elaborate steep ascents with two birds 39 to 68 inches apart, and both make cackling calls. We suspected that a collision between two woodcocks had killed one of them.

That was the last I heard or saw woodcocks until May 9 on International Migratory Bird Day (IMBD). By then we were caught up in migratory songbirds and I was out by 8:45 am to count birds. I started up First Field Trail and immediately flushed what I assumed were two female woodcocks since male woodcocks give no parental care but hens sometimes share feeding grounds. One female performed her broken wing act while at least three half-grown fledglings ran in all directions with the second female. I walked on quickly so they could recover from my interference.

Three days later, Bruce took First Field Trail in search of a wild turkey sitting on her nest that Mark had discovered the previous day. But he disturbed one female woodcock with her three fledglings and again she performed her broken wing act while the young ran off.

A hen turkey (Photo by Doug McAbee on Flickr, Creative Commons license)

A hen turkey (Photo by Doug McAbee on Flickr, Creative Commons license)

Surprisingly, the turkey hen was still on her nest and didn’t move. I had kept away from the trail since IMBD, because I didn’t want to disturb the woodcock family. I was reminded of a book I used to read to our sons called Frog and Toad Are Friends, and thought “Woodcock and Turkey Are Friends,” since it looked as if the two species had nested and fed in the same area for weeks.

American woodcocks are shorebird species that prefer to nest in a wet woodland habitat. In Pennsylvania they are probably the earliest migrant species to breed in most places. Because of their unusual appearance and behavior, they have numerous nicknames—night partridge, mudbat, bog sucker and big-eye. They live throughout eastern North America from southern Canada to the southern United States.

A woodcock nest with eggs (Photo by Brian Wulker on Flickr, Creative Commons license)

A woodcock nest with eggs (Photo by Brian Wulker on Flickr, Creative Commons license)

Female woodcocks construct their nests in underbrush or tall weeds along the edges of woods and often at the base of a small tree or bush. They make shallow depressions–5 inches across and 1.5 inches deep– in leaf and twig litter, lay one to five grayish-orange eggs splotched with brown, violet-gray or blue-gray, and incubate them 19 to 22 days. Except for brief periods to eat, mainly earthworms but also insects, such as beetles, ants, crickets and grasshoppers, as well as millipedes, spiders, and centipedes, females sit still on the nest and blend into the brown and beige leaves around them.

Numerous nest predators include free-roaming dogs and cats, skunks, opossums, raccoons, crows and snakes, but most young survive the nesting and juvenile periods to live on average 1.8 years, although the oldest known woodcock was 11 years, four months.

Woodcock chicks (Photo by Jerry Schoen on Flickr, Creative Commons license)

Woodcock chicks (Photo by Jerry Schoen on Flickr, Creative Commons license)

Judging from the brief glimpse I had of the young, they were a little less than two weeks old and had been using their flexible upper bills to probe for earthworms and other underground food for more than a week. When they are two weeks old, the young can fly short distances. At four weeks of age, they are almost fully grown, fly well, and look like their parents.

Once the young can roost at night on shrubs in old fields in mid-June or July, they gradually separate from their siblings at six to eight weeks old. They migrate from most of Pennsylvania when the ground freezes the last week in October to the second week in November. I saw my last woodcock on November 5 when it flushed from the shrubby edge of the mostly overgrown Far Field a half mile beyond First Field.

Woodcocks appear to be widely distributed in Pennsylvania, although the early successional habitat they use is disappearing as forests age and old fields are converted into commercial and housing developments. We long ago converted our 37-acre hayfield into a meadow with shrubs and saplings on all sides and singing male woodcocks have been increasing every spring.

But last spring was the first time we encountered positive proof of breeding woodcocks. And that is why First Field Trail is now called Woodcock Trail.

 

Counting Raptors in Mid-Winter

Last winter was the 20th year of the Winter Raptor Survey. This innovative survey is the brainchild of Greg Grove, who is a retired biochemist from Penn State University, the compiler of the Stone Mountain Hawk Watch and the editor of Pennsylvania Birds magazine.

Winter in Sinking Valley as seen from Laurel Ridge (Photo taken in December 2016 by Dave Bonta, on Flickr)

Winter in Sinking Valley as seen from Laurel Ridge (Photo taken in December 2016 by Dave Bonta, on Flickr)

The Winter Raptor Survey (WRS) is designed to count all raptors and vultures along pre-determined back road routes through open habitat in Pennsylvania. These routes vary in length from between 25 and 90 miles and remain the same from year to year.

We signed on the first year to run a route in Sinking Valley, a mostly open farm valley between Tyrone and Altoona in Blair County, a valley that I gaze down at every time I take a walk on our Laurel Ridge Trail. This valley has both Amish and modern farm operations and is almost entirely enclosed by forested Bald Eagle (locally known as Brush) Mountain. Much of the mountain not owned by private persons is part of SGL#166.

My husband, Bruce, designed our 34-mile route around this small valley, and I have been the principal observer most years, although occasionally we’ve been joined by one or the other of our two birder sons, Steve and Mark. Last winter Mark joined us, sitting in the front passenger seat, while I occupied the back seat and Bruce, as usual, was the driver.

Unlike the Christmas Bird Count, where counters have one pre-designated day to count birds, WRS participants can choose any date set by Grove over a several week period. Last winter it was January 12 to February 17. We chose a 32-degree, overcast morning with a light breeze in late January.

A red-tailed hawk in Hanover, PA (Photo taken in February 2008 by Henry T. McLin, on Flickr, Creative Commons license)

A red-tailed hawk in Hanover, PA (Photo taken in February 2008 by Henry T. McLin, on Flickr, Creative Commons license)

Shortly after beginning at 8:51 am, we spotted a mature red-tailed hawk sitting high in a tree on a road where we had never before seen a raptor during our previous surveys. This sighting seemed to be a good omen for our WRS.

But we drove for several miles, seeing no raptors until we neared a farm field at the entrance to Fort Roberdeau County Park. There we stopped to watch a turkey vulture and two black vultures picking over the carcass of a small deer. They were the first vultures we had ever gotten on a WRS.

Black vultures in Gettysburg, PA (Photo taken in January 2007 by Henry T. McLin, on Flickr, Creative Commons license)

Black vultures in Gettysburg, PA (Photo taken in January 2007 by Henry T. McLin, on Flickr, Creative Commons license)

As it turned out, according to Grove’s article in Pennsylvania Birds (Dec. 2019-February 2020) entitled “The 2020 Winter Raptor Survey in Pennsylvania,” the mild winter weather caused record numbers of both vulture species to stay north, especially in southeastern Pennsylvania with Lancaster and Chester counties accounting for 43% of all recorded vultures in the state. In addition, Greg wrote, “Turkey and Black Vultures were found in 39 and 29 counties, respectively, both the highest ever for the Pennsylvania WRS.”

We couldn’t count or even identify the vultures high in the sky heading for the farm field because a sudden snow squall hit, and Bruce could barely see the road. Luckily, we soon drove out of the snow and on to a series of back roads, mostly in the Amish section of the valley, where we spotted a pair of adult bald eagles on one distant field that flew off and over an incline. Probably they were the pair that had set up housekeeping on the other side of our mountain on the game lands.

Bald eagle in Hanover, PA (Photo taken in February 2007 by Henry T. McLin, on Flickr, Creative Commons license)

Bald eagle in Hanover, PA (Photo taken in February 2007 by Henry T. McLin, on Flickr, Creative Commons license)

Grove later reported that while the 20th WRS bald eagle count of 509 was less than the record-setting 600 of the 2018 WRS, it too could be accounted for by the mild winter. During colder winters, bald eagles congregate on one route in Bucks County along the Delaware River and another in Lancaster County along the Susquehanna River where there is plentiful food, but in 2020 the birds weren’t as dependent on those two major rivers. Still, despite being recorded in 56 counties, Lancaster with 81 and Bucks with 42 still had the highest numbers.

On an electric line along another back road directly below an Amish farm owned by a family that erects a couple purple martin houses every spring, perched our only American kestrel, a lovely male. Again, the mild weather led to a higher than usual kestrel count for Pennsylvania (623), the fourth highest ever; the highest (711) occurred in 2017. Franklin County was way out in front with 50 kestrels. Most years we manage to find a single kestrel somewhere in the valley, although on a longer route in the southern part of our county, seven kestrels were recorded in 2020.

American kestrel in Chester County, PA (Photo taken in February 2012 by Kelly Colgan Azar, on Flickr, Creative Commons license)

American kestrel in Chester County, PA (Photo taken in February 2012 by Kelly Colgan Azar, on Flickr, Creative Commons license)

In an email to me, Grove wrote that the 20 years of WRS data “shows evidence of kestrel decline especially in eastern Pennsylvania.” Furthermore, “the WRS has shown the importance of the ridge and valley farmlands, where most of the kestrels winter.”

The rest of our route was less exciting, but we managed to find four more mature red-tailed hawks sitting on trees in different parts of the valley. Statewide, red-tailed hawks numbered 3242 with Huntingdon County’s tally, at 150, the highest.

Even though we had our best WRS ever, with five species, we had missed northern harriers, another open country raptor. According to Grove’s article in Pennsylvania Birds, northern harrier numbers are dependent on several factors such as their small mammal prey base in open fields and the newly-reported study by hawk watch researchers that has uncovered the harriers’ four-year population cycle. But most important of all was probably the mild weather and lack of snow cover that led to a 104 count in 2020 compared to the lowest ever of 59 during the cold and snowy 2019 winter. Grasslands on reclaimed strip mines are particularly favored by northern harriers and thus the Clarion County grasslands, free of snow-cover in 2020, led the state with 12.

Rough-legged hawks, a northern species that breeds in North America from Alaska to Labrador, winter across Canada and throughout much of the United States including Pennsylvania. They too prefer large open fields with small mammal prey. But only 30 were recorded, the lowest number per hours surveyed during the 20 years of the WRS. Most of them were scattered across the northern half of the state, but the highest number occurred in eastern Centre County with five in Penn’s Valley.

Red-shouldered hawk in Indianola, PA (Photo taken in January 2014 by Steve Valasec, on Flickr, Creative Commons license)

Red-shouldered hawk in Indianola, PA (Photo taken in January 2014 by Steve Valasec, on Flickr, Creative Commons license)

Red-shouldered hawks, in contrast, continue to increase their numbers every year, setting another record in 2020 of 188. Most of them were concentrated in southeast and south-central counties with 31 in Adams County, although Butler (18), Crawford (14) and Mercer (13), all in the northwest, had the next highest counts. These forest-loving hawks have traditionally bred and wintered in lowland deciduous or mixed forests interspersed with wetlands and also in the forested mountain valleys, according to McWilliams and Brauning in The Birds of Pennsylvania.

But Grove in his email wrote that, “The most dramatic increases are in the southeast, and others have been speculating that Red-shoulders may be becoming somewhat ‘suburbanized.’ We can also see support for the idea that Pennsylvania’s breeding Red-shoulders apparently stay on territory through winter—evident in the large number of WRS RSs [Red-shoulders] in NW PA, even though weather there is [the] most severe in the state.”

Cooper’s hawk in Plummer’s Hollow (Photo taken in May 2020 by Mark Bonta)

Cooper’s hawk in Plummer’s Hollow (Photo taken in May 2020 by Mark Bonta)

Other forest raptors had lower numbers than red-shoulders—113 Cooper’s hawks, 39 sharp-shinned hawks, five golden eagles and only a single northern goshawk in Franklin County. The much higher count of Cooper’s hawks reflect growing numbers in the state, in contrast to the dwindling numbers of sharp-shins. Both prey on songbirds at feeders during the winter and provide excellent views to those of us who are feeder watchers. Like sharp-shins, northern goshawk numbers have been falling in Pennsylvania and are now listed as Vulnerable in the state’s Wildlife Action Plan. Most eastern golden eagles, which nest in northern Quebec Province, head further south than Pennsylvania in the winter.

And finally the 16 merlins and 12 peregrine falcons statewide inhabit open country near water and near or in urban areas. Merlins only recently began breeding in northern Pennsylvania, their southernmost breeding area in the eastern United States. During the second breeding bird atlasing period six nests were confirmed in Bradford, Sullivan, Pike and Warren counties. However, during the WRS merlins were found in the central and southern counties. There were four peregrine falcons in the northwest and the rest in central and southern Pennsylvania.

Pennsylvania hawk watchers continue to have enthusiasm for the WRS and now run over 200 routes in 66 of our 67 counties. Grove thinks that’s because we are a top hawk-watching state and birders are looking for an excuse to get out in mid-winter and count birds.

When Grove first launched the WRS, he had already been looking for wintering hawks on his own, but “I thought it would be worthwhile to do so using consistent, repeated routes in order to get data that would have some degree of scientific value. To look for trends over years and make distribution maps.”

And that’s exactly what has happened. Congratulations to Grove for brightening our winter days!

 

Butcher Bird

A week of light snow, followed by sleet and freezing rain last January, turned our mountain into an ice rink and penned me inside until it warmed above freezing. That occurred on January 25 when it was 36 degrees and dripping rain at dawn.

A northern shrike on an electric wire beyond our barn (Photo by Mark Bonta)

A northern shrike on an electric wire beyond our barn (Photo by Mark Bonta)

Late that afternoon our son, Mark, who was living in our guesthouse, called to tell me there was a northern shrike perched on the electric wire beyond our barn. I pulled on my boots and jacket and walked slowly downhill to where Mark was standing between the barn and the shed. There I had an excellent view of the shrike, which kept turning its head to look at us and twitching its tail. Mark then circled around the barn to Butterfly Loop, hoping to take a closer photograph of the bird.

But the shrike flew down past me and into the top of a small tree near the guesthouse. Next it flew into the tallest front yard black locust tree. Finally, the shrike flew away. I was thrilled because that was the first time I had ever seen one.

There was no trace of brown on the bird, which meant that it was an adult northern shrike. It looked like a brighter-colored version of a northern mockingbird with a gray head and back, black wings and a tail marked with white, a white throat, breast and belly, but it also had a distinctive black mask.

Early the following morning Mark searched for the shrike and found no trace of it. However, later in the morning, as I descended the Amphitheater Trail in First Field, I spotted the shrike at the top of a black walnut tree near the shed. But it flew off. Then, as I approached the house, it suddenly flew over the roof and away. A few minutes later Mark located it across First Field at the top of a catalpa tree.

A northern shrike with its prey (Photo by Kelly Colgan Azar on Flickr, Creative Commons license)

A northern shrike with its prey (Photo by Kelly Colgan Azar on Flickr, Creative Commons license)

The shrike had been using the wire and tree perches to hunt for prey. Called a “butcher bird” because it not only has a hook-tipped bill with which it kills prey with a bite to its neck but often it impales it on thorns or barbed wire or shoves it into forked branches for later consumption. Ten-inch northern shrikes will kill birds larger than themselves, for instance, 12-inch mourning doves and 11-inch blue jays. In the winter they are also looking for meadow voles and white-footed mice to consume.

Although we kept looking, we saw no further sign of the shrike until February 9. It was 31 degrees at dawn and the ground was covered with a light snow that had fallen overnight. I headed out at 9 am, bound for Greenbrier Trail. As I ambled along Butterfly Loop toward Margaret’s Woods, I paused to admire the snow-covered landscape. A bird, its tail twitching, was perched on top of the same catalpa tree across First Field where Mark had last seen the shrike. At first I thought it was a crow but through my binoculars I could see that the northern shrike was making a return visit after its first visit two weeks before. As I neared the tree it flew away.

I resumed my walk but coming back across First Field two hours later, a spot of white in a black locust tree at the base of Sapsucker Ridge turned out to be the shrike. From there it flew to the top of a pear tree and then into a black walnut sapling at the edge of First Field close to where I was standing. Lastly, it flew behind the barn and back across the field to the catalpa tree.

I had been trying to contact Mark since my early morning sighting, but he had been off birding at the Far Field. Finally, both he and his brother Dave joined me, and we all had a look at it back in the small locust tree at the base of Sapsucker Ridge. And that was our last glimpse of the elusive boreal songbird. It had enlivened what had been a dull winter for birds since neither northern finches nor red-breasted nuthatches had irrupted from the north.

A northern shrike in British Columbia (Photo by Murray Foubister on Flickr, Creative Commons license)

A northern shrike in British Columbia (Photo by Murray Foubister on Flickr, Creative Commons license)

Northern shrikes are also an irruptive songbird that breeds in the shrubby north from Labrador and Quebec to western Alaska. Many of them migrate south to southern Canada and the northern United States during late autumn and early winter. Every three to six years their numbers peak, and northern shrikes can be found as far south in the eastern United States as Virginia.

Most years, five to ten northern shrikes are observed in Pennsylvania especially in the northwest. They prefer to hunt on open brushy fields, which describes our First Field, as well as farm fields and strip mines. They may also hang out near bird-feeding stations and catch songbirds.

Last winter only four northern shrikes were found during the statewide Christmas Bird Count (CBC) and three during the 2020 Winter Raptor Survey (WRS), which is held from mid-January until mid-February. All three of the WRS shrikes were reported from northwest counties—Warren, Clarion, and Butler. The closest reported shrike to us was one at Bald Eagle State Park during the CBC. Irruptive northern shrikes have not been well-studied but sometimes they hold large territories of several hundred acres. Otherwise, they wander widely.

The largest recorded irruption of northern shrikes throughout North America happened in 1995-96, but in Pennsylvania it was the third largest with 50 shrikes in 29 counties. The largest in our state occurred the winter of 1999-2000 when there were 137 shrikes in 47 counties.

A northern shrike at the John Heinz NWR, Philadelphia (Photo by Brian Henderson on Flickr, Creative Commons license)

A northern shrike at the John Heinz NWR, Philadelphia (Photo by Brian Henderson on Flickr, Creative Commons license)

Paul Hess wrote a comprehensive article for Pennsylvania Birds on this irruption. It began with the sighting of two northern shrikes on October 24 in Erie County, which Hess described as “the state’s most regular shrike location even in non-invasive years.” By November, after the first strong cold front, shrikes were being reported statewide. Thirty were counted on CBCs in December and early January and shrike sightings continued until early March. Berks County in eastern Pennsylvania had the highest number (12).

Because there are few accounts of shrike ecology in North America, Hess summarized three notable features of our irruption, namely that 53% of shrikes (48) were adults and 47% (40) were immatures.

Secondly, only 20% held territories, and they were mostly adults, while the rest wandered, responding to food and weather conditions.

A house sparrow killed by a northern shrike at a bird feeder in North Dakota (Photo by Matt Reinbold on Flickr, Creative Commons license)

A house sparrow killed by a northern shrike at a bird feeder in North Dakota (Photo by Matt Reinbold on Flickr, Creative Commons license)

Thirdly, the prey they caught were primarily songbirds at bird feeders because meadow voles were scarce that year throughout the state.

Since that irruption, Pennsylvania has had two more, according to Greg Grove, who started the Winter Raptor Survey in 2000. Our second largest shrike irruption was 2007-08 with 80 shrikes in 39 counties. That was followed by a smaller irruption in 2011-12 with 44 shrikes in 27 counties.

Northern shrikes start returning north from Pennsylvania by the fourth week in February or first week in March. While they may pair up on winter territories, even far south, most courtship chasing, feeding, and aggressive displays by males toward females occurs on their breeding grounds.

Both sexes also sing either two-phrase, thrasher-like imitative songs of nearby bird species or sweet warbles and harsh screeches.

A juvenile northern shrike (Photo by Eric Ellingson on Flickr, Creative Commons license)

A juvenile northern shrike (Photo by Eric Ellingson on Flickr, Creative Commons license)

The male feeds the female during late courtship, nest-building, laying, incubation and the early nestling period. The female chooses the nesting site in late April or early May in shrubby willow trees or spruce conifers. She places it in a fork of a branch near the trunk usually eight feet from the ground. She also brings most of the nesting materials aided by the male. The nest is a large, deep, bulky cup filled with ptarmigan feathers, animal hair, and dried moss and lined with grasses and sedges.

In the nest she lays 4 to 9 grayish or greenish white eggs spotted heavily with brown and incubates them 14 to 21 days while the male is busy feeding her and defending a 360-acre hunting territory as well as a 7-acre nesting territory. Mostly the male hunts for grasshoppers, beetles, bumblebees, insect larvae and spiders during the summer months.

The offspring spend 18 to 20 days as nestlings and another several weeks as fledglings being fed by their parents and taught how to hunt. By mid-summer the fledglings are on their own, and sometimes the siblings stay together and join other broods of immatures as they continue to hone their hunting skills.

By mid-September these groups disperse and individually move along river corridors out of the boreal forest into open country. They also follow ridge lines like small hawks do, flying just above the tree tops as they head south for the winter.

Because seeing a northern shrike here in winter is a rare privilege, I don’t expect to see one hovering over our First Field this winter. But Pennsylvania is overdue for another northern shrike irruption