Superflight

red-breasted nuthatch

red-breasted nuthatch (photo by Matt MacGillivray, Creative Commons Attribution licence)

It began with red-breasted nuthatches. In early August 2012, one of the largest irruptions of this northern species in living memory started with reports from counties in eastern Pennsylvania. By the end of November unprecedented numbers were recorded in all 67 counties in the state.

In late September the first purple finches arrived in Pennsylvania and 63 counties had them by late November. Common redpolls and pine siskins began appearing in early October, evening grosbeaks by the last week in October, and both white-winged and red crossbills in early November. Even a few hoary redpolls and a couple pine grosbeaks made an appearance.

With so many northern finch species moving south, birders called it a superflight, which happens only once every decade or so when food sources fail in the north, forcing most conifer seed-eating species to fly south for food. I was especially excited that red and white-winged crossbills were in Pennsylvania, because our son, Steve, had had the only sighting of white-winged crossbills on our property eating hemlock seeds here in the winter of 1985 when I was in Peru. And I had never seen red crossbills.

Now that our hemlocks are dying from woolly adelgids, we could only hope to see crossbills in our 38-year-old Norway spruce grove at the top of First Field. By the first of October several red-breasted nuthatches had already arrived there.

white-winged crossbill

white-winged crossbill (OwenMartin12, CC BY-NC)

Then, on November 15, I hiked to the spruce grove. Black-capped chickadees and red-breasted nuthatches foraged in the spruces at the base of the grove. But I heard an unfamiliar bird call and wandered through the grove searching for the source of it. Finally, I gave up, walked out of the grove and glanced back at the spruces one last time. At the top of a spruce two white-winged crossbills perched. They remained long enough for me to admire white wing bars on black wings, rosy pink breasts, heads, and backs, and even the crossed bills of two beautiful males. At last I had seen crossbills on our property.

Previously, in early November, I had had a male and then a female purple finch at our feeder area for more than a week as well as pine siskins for three days and, as it later turned out, they were the only pine siskins and purple finches to visit us during fall and winter. But already I had seen four irruptive species, and it was only mid-November.

Then a bout with Lyme disease, followed by a nasty virus, kept me inside for several weeks. It took time for me to regain my strength, and I was grateful when our Christmas Bird Count arrived on December 15, that Kurt Engstrom and his keen birder son Carl, came once again to help me. They covered the much longer and more difficult section on Sapsucker Ridge and up our road while I walked a mile and a half on Laurel Ridge.

In the spruce grove I searched for red-breasted nuthatches and white-winged crossbills, but the grove was silent. I was tired and sank down on Alan’s Bench to rest. After a short wait, I heard the call of a red-breasted nuthatch.

red crossbills

red crossbills in Long Branch, NJ (John Beetham, CC BY licence)

However, I did not recognize the call of another bird coming from the upper edge of the grove. I turned my head in that direction and spotted what appeared to be a dull-colored bird at the top of a spruce tree, continually calling, looking around, and flicking its forked tail. It had clouded over, making it difficult to distinguish any color on the bird. I kept studying it through my binoculars, and finally noticed that it had a crossed bill. When I pished, in an attempt to bring it closer, it flew away still calling.

I had listened to it for so long that the call was seared in my brain. After studying my bird guides, I was almost certain the bird had been a female red crossbill. Still, when Kurt and Carl returned, I told them what I had seen and heard. Carl didn’t say anything. He just started playing a series of calls on an Audubon Birds app on his iPod.

“That’s it,” I said.

“Number 3 type of red crossbill,” he answered. “Exactly the type of red crossbill that should be here,” he replied.

I was ecstatic. A new species—number 171—for our property and, as it turned out, the only crossbill reported on our Juniata Valley Audubon Society’s Christmas Bird Count. My red-breasted nuthatch was also the only one on our count.

Red crossbills live throughout the northern regions and high mountains in Europe, Asia, North America, and even the Atlas Mountains of North Africa. Here in North America ornithologists have teased out at least ten types of flight calls by red crossbills north of Mexico that some feel may be discrete species and others merely races or subspecies of red crossbills. Type 1, 2, and 10 calls were also heard in Pennsylvania, although type 3 was the most common. The calling of the lone red crossbill I saw may have been an effort to attract other red crossbills to a feeding source, according to some researchers.

Red crossbills prefer to feed on attached cones, using their feet and crossed bills like parrots to pry open the cones. Then they husk the seed coating by pressing a seed against the lateral groove opposite the side of the lower mandible tip with their tongue. Small seeds they swallow whole but crush large seeds in their bills before swallowing them.

white-winged crossbill (Jean-Guy Dallaire, CC BY-NC-ND)

Both white-winged and red crossbills have straight upper mandibles. Only the lower one curves, and while three-quarters of white-winged crossbills’ lower mandibles curve right and the other quarter left, red crossbills’ lower mandibles curve right half the time and left the other half.

Even though both crossbills eat conifer seeds, red crossbills prefer the cones of pines, including white, pitch, scrub, scotch, red, and even table mountain in our area, but they will also eat hemlock, spruce, tamarack, and occasionally the seeds of deciduous trees.

White-winged crossbills prefer the softer cones of hemlock, spruce, and tamarack, but they will also take seeds from pines with stiff cones and occasionally those of deciduous trees. Researchers claim they eat as many as 3,000 seeds a day.

While both species sometimes visit bird feeders, I never saw either one at our feeders. I had plenty of time to observe them because I no sooner had I gained my strength back in early January than I was diagnosed with a deep muscle tear in my left calf which kept me inside for nearly seven weeks. That’s when I began to refer to last winter as the winter of my discontent.

I did see at my feeders the sixth irruptive species—a male common redpoll that appeared on December 21. He or another male and a female showed up on January 3, and on January 6 and the two following days, a flock of more than 30 common redpolls blanketed the ground and feeders. The bright red forehead and black chins of both sexes and the pink breast of the male are the distinguishing features of these mostly brown-streaked birds. I never did see a hoary redpoll among them.

I similarly failed to see an evening grosbeak at our feeders, even though this species made its best showing in over a decade in Pennsylvania appearing in 33 counties.

Although most were gone from the state by mid-December, up to 150 at a time appeared at a feeder in Marienville, Forest County.

common redpolls in flight

common redpolls in flight (Jean-Guy Dallaire, CC BY-NC-ND)

Numbers of both crossbill species also diminished by mid-December. White-winged crossbills went from 43 counties in early November to 35 in the winter and red crossbills from 30 counties in early November to 20 in the winter.

During similar irruptive invasions of red crossbills in Pennsylvania, most appeared in mid-to-late October and left the state by the end of March. Although they remain paired through most of the year and may breed at any time an area suits them, there are very few verified sightings of breeding red crossbills in Pennsylvania.

White-winged crossbills arrive and leave on the same schedule as red crossbills, and there are no records of breeding here. During one of the largest crossbill invasions in Pennsylvania in 1997-98, over 1,000 white-winged crossbills spent the winter in Cook Forest State Park and were often joined by lesser numbers of red crossbills. But we never saw them on our mountain then, probably because our spruce grove was only 24 years old and not producing a good cone crop. So last winter will remain in my memory as our crossbill winter, my first ever in the 41 years I have lived on our central Pennsylvania mountaintop.

Putting Up the Feeders

cardinal pair in a snowstorm

cardinal pair below the feeders in a snowstorm

The day after I cleared the trails of branches brought down by Hurricane Sandy, I hung my birdfeeders up for the first time since the previous April. Because bears live on our mountain, I never tempt them with birdseed, having learned years ago that they will go to great lengths to make a meal of them and, in the process, tear feeders apart.

Even so, I bring them in every night until mid-December and again in March and early April.

I only put the feeders out as early as November because I am a veteran Project FeederWatch participant, having signed on for this citizen science project, developed by the Cornell Lab of Ornithology, the first year it was offered. Last fall was its and my 26th season, and it began on November 10.

Anyone can join this continent-wide effort by paying a small fee and either sending in paper copies of their count or doing it online at the Lab’s website. If the former, feeder watchers count birds at and near their feeders two consecutive days every two weeks. If the latter, as I do, I can count birds two consecutive days every week. Since I have a reasonably small and simple set-up, mostly I glance out my back kitchen door window and keep a tally card nearby.

The idea is to count the maximum number of each species that I see at one time during my count days. Folks with larger and more elaborate feeding areas containing numerous feeders, sources of water and plantings can report all the species attracted to their much larger count site.

In addition to reporting the birds I see, the report asks for when and how long I counted, the depth of snow and/or ice, the kind and length of time of any precipitation, and the low and high temperatures of the days. Once a season I also fill out a detailed description of my count site including the habitat within a half mile, elevation, the kinds of food I supply for the birds, and the plantings and water sources within 100 feet of my feeders.

Usually I give the birds a week before the start of the season to re-discover the large and small tube feeders that hang from our back porch. Last November third it was cold, overcast, and windy, and as soon as my feeders went up and I spread more birdseed below the back steps, the dark-eyed juncos, back from the north, flew in. They were quickly followed by full-time residents—white-breasted nuthatches, tufted titmice, and a red-bellied woodpecker. Next, song sparrows and American goldfinches, a few of which are full-time residents, appeared and so did the first white-throated sparrow of the season, also down from the north.

pine siskin and house finch

pine siskin and house finch

The seventh species to appear was a house finch. Here on our mountain they continue to be late fall and early winter visitors and are often gone by February. Project FeederWatch asks that participants note the presence or absence of eye disease in this species and in goldfinches. I’ve never seen this bacterial infection in the latter but sometimes in the former and I wonder if that is why their numbers peak and crash so soon. Years ago, when this western species, accidentally introduced to the East back in 1940, finally arrived on our mountain, they even nested here. But then their numbers crashed when they developed eye disease, and they never nested here again.

The house finch was followed by a black-capped chickadee and a male and female northern cardinal—two more permanent residents.

And then—glory be—25 pine siskins. Could this boreal bird species be the vanguard of an influx of rare northern birds? Every November a few pine siskins and common redpolls are reported by feeder watchers in Pennsylvania and hopes are raised that this will be the winter for a huge irruption of seed-eating birds from Canada. Reports of a widespread failure in seed-crop production, especially of spruces and birches, had already reached bird listservs so I was delighted to welcome the pine siskins.

The eleventh species of the day was one of our Carolina wrens, now successfully wintering as our climate warms and raising families here in the spring and summer.

A migrating swamp sparrow was the twelfth and last species that day. Never before had so many species appeared the first day I put out the feeders.

swamp sparrow

swamp sparrow below the feeders

The following day a fox sparrow appeared. This lovely, large sparrow always visits us on it way north in the summer and south in the winter. Because of its size—seven inches—it could easily dominate the smaller birds as it scratches towhee-like at the seeds below the back steps, but usually this rusty-tailed sparrow is off by itself, completely ignoring the juncos, song sparrows, and other ground-feeding birds.

Number 14 the next day was the gorgeous male purple finch, his head, breast and rump a rosy-red more brilliant and wide-spread than his close relative the house finch. But unlike the house finch, the purple finch belongs in eastern North America.

The female purple finch, like the house finch, is a study in brown and white, but she is chunkier and has a face patched with dark brown and a white stripe behind her eye.

“Don’t you see,” I frequently say to my husband, Bruce, when I try to point out the difference between the two species. But he doesn’t see what seems so obvious to me.

Then number 15, the American tree sparrow, another northern-breeding species, appears, and Bruce throws up his hands, muttering something about lbjs, better known as “little brown jobs” among birders in the know who can distinguish the many similar-appearing sparrow species and other difficult to identify birds such as the often different colored females. Unlike the seed-eating boreal species, tree sparrows are regulars at my feeders every winter. With its rusty-red head and black dot on its white breast it’s an easy sparrow for me to identify.

common redpoll

common redpoll at the feeder, January 2008

Numbers continued to increase day by day and the sixteenth species, on November sixth, was a sharp-shinned hawk. On that day it didn’t catch a meal because all the birds heeded the chickadee’s warning call and fled.

On the seventh a blue jay and a mourning dove joined the feeder birds while the male purple finch continued to hang around. Already, I was anticipating an excellent FeederWatch count.

But the weather warmed up, and it was a true Indian summer day. The second day was too. As a consequence, both the numbers and species were low—two white-breasted nuthatches, five American goldfinches, three tufted titmice, two black-capped chickadees, 12 house finches (one with eye disease), two red-bellied woodpeckers, three dark-eyed juncos, one song sparrow, one cardinal, and one purple finch. At least I had gotten a purple finch, but on the eleventh it was a male and the twelfth a female, yet, according to the rules, I could only count one purple finch. The same was true for the northern cardinals.

The thinking is that since the male and female of most feeder bird species look similar and are counted as a group, those that are sexually dimorphic, such as the cardinals and purple finches, must be treated the same way. Hence, even though I knew that two cardinals and two purple finches came to my feeders, I could only report one unless both sexes appeared together which, in this case, they did not.

sharp-shinned hawk at feeder

Sharp-shinned hawk at the feeder

The weather continued mild throughout the month and into mid-December, much to my disgust as a feeder watcher and the disgust of our deer hunters. I never did see another pine siskin, and my feeder counts remained low except for the juncos that increased to 20 by the end of the month. The sharpie also returned on that last November count, but once again it didn’t score.

The sharpie waited until the day before Christmas. Our Newfoundland daughter-in-law Pam called us to the bow window and pointed out the sharpie eating a female cardinal on the ground below. She took some photos of it in action that even showcased its orange eyes outlined in black.

Having gotten a meal, it was back the last day of December sitting on an ash tree branch close to the bow window in mid-afternoon for over half an hour. It wasn’t even disturbed by Bruce attaching his camera to the front of our spotting scope and taking frame-filling photos with his “digiscope” on the second day of a FeederWatch.

Such are the rewards of keeping a close watch on the birds that visit our feeders throughout the winter months. In addition, the records we send into Project FeederWatch, along with feeder watchers all over the continent, enable ornithologists to better understand the distribution of wintering birds and to track emerging diseases, such as the eye disease, and other problems birds may face.


All photos taken at Marcia’s birdfeeders. The first four are by Dave; the last is by Bruce, taken through his “digiscope” set-up.