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.

They Came and They Went

It took house finches almost 43 years to make it from Jones Beach, Long Island, where birders identified the first wild eastern house finches, to our mountaintop in central Pennsylvania, even though they had been frequenting bird feeders in nearby valleys for seven years.

I know the exact date the first house finches appeared at our feeders–December 30, 1983. That was when I noticed a drab, brown-striped female eating by herself. A few seconds later, she was joined by a flashy male house finch. By April we had two pairs nesting in our yard.

We took them for granted back in the 1980s and early 1990s. As many as 75 mobbed our feeders during the winter, and a pair or two were always courting by late February. Most people dismissed them as just another invasive species like European starlings and house sparrows. Yet unlike those European immigrants, house finches are native Americans.

They originated in western North America, ranging from south central British Columbia to Oaxaca, Mexico, hence their scientific name Carpodacus mexicanus, which means “fruit biter of Mexico.” They especially favored the valleys of the Pacific slope of central and southern California. Once inhabitants of undisturbed wild places, they easily adjusted to our changes in the landscape and have subsequently thrived in our cities, suburbs, and farms, building their nests in a variety of places such as in yard trees, on ledges, in ivy on buildings, on street lamps, and in hanging planters.

Because these western house finches were known for their “rollicking, warbling” songs and the brown-streaked males for their colorful bright red or orange breasts and rumps, they were illegally captured, caged, and shipped to the eastern United States where they were sold as “Hollywood” finches in New York. When United States Fish and Wildlife Service agents moved to stop the trade, those dealers who possessed house finches quickly released them on Long Island to avoid arrest.

Although house finches took ten years to spread into nearby Connecticut and New Jersey, by 1980 house finches ranged as far north as southern Maine, west to southern Michigan and western Illinois, and south to Georgia, Alabama, and Mississippi. They weren’t quite the same bird though. Some eastern house finches learned to migrate and, as a result, their wing structure differs slightly from their western counterparts that never migrate.

Their songs have also changed. Male house finches in the eastern United States have local dialects, unlike those in the West. On the other hand, western house finches have far more diverse songs than those in the East.

The songs are sung almost year around, mostly by males, although occasionally females sing too. Males seem to sing to attract females, to show aggression to other house finches, and even for their own pleasure. Because there are many more males than females, competition for females in winter flocks, where they pair up, is fierce.

Most pairs are faithful through the nesting season, even though some occasionally switch mates. Others stay together and nest in subsequent years. Such pairs breed earlier and are more attentive to each other. The males more carefully tend the females as they sit on eggs, and the females are more likely to follow the males during nest-vicinity fights than those of later, presumably novice breeding pairs.

After the males’ frequent performance of their “butterfly flight” in which they slowly climb skyward and then glide back to a perch while singing loudly, pairs begin billing and then courtship feeding. That leads to nest-building, mostly by the female, and copulation. The male also fiercely guards the female during this period and through egg-laying.

House finches build their nests from mid-to-late March and lay between four and five eggs. In most places they have two or three nestings by late July. The females incubate the eggs from thirteen to seventeen days, depending on how cold the weather is, and after the eggs hatch, the parents feed the nestlings plant food which they regurgitate from their crops. The young fledge anywhere from twelve to nineteen days.

As with other invasive species, house finch numbers exploded in the eastern United States. They became the most common backyard bird in the country, pushing their closest relatives, purple finches (C. purpureus), as well as American goldfinches, from feeders. By 1991 estimates of individual house finches in North America ranged from 267,720,000 to 1,440,720,000.

Then, in 1994, disaster struck. In February Maryland feeder watchers noticed house finches with red, swollen, runny and crusty eyes. Scientists quickly determined that they had a respiratory infection, which they called conjunctivitis, which was caused by the bacterium Mycoplasma gallisepticum. A common disease in domestic turkeys and chickens, it had never before struck songbirds. Within ten months the house finch disease had spread from eastern Ontario to southern Virginia. Two and a half years later, folks across eastern North America had reported the disease at their feeders.

As a veteran participant in Cornell University’s Laboratory of Ornithology’s Project FeederWatch, that began in 1988, I was asked, along with the thousands of others in the program, to join their House Finch Disease Study. After two years of seeing no signs of disease in my flock, I withdrew from the study. But I continued my participation in Project FeederWatch. Through 1996-97, my house finch numbers remained in the sixty range. Then they started to fall. Still, I saw no sign of the disease. By 2001, my average flock size was three. That was the year when Cornell reported that house finch numbers had dropped a whopping sixty percent.

Conjunctivitis usually didn’t kill house finches outright, but they were essentially blind and couldn’t see to eat or evade predators. So they died from starvation, exposure, or predation.

House finches had long since ceased breeding here, and last winter, for the first time, not one house finch came to my feeders. At the same time, our American goldfinch flock rose to seventy-five. We also saw more purple finches in the late fall.

I wondered if others in Pennsylvania had had a similar experience, but of the fourteen people across the state who answered my query on the Pennsylvania Bird listserv, only one person reported no house finches. Almost everyone else had low numbers–6 to 8–except for Philadelphia, suburban Harrisburg, Quakertown, and Nazareth, Northampton County where numbers ranged as high as 25. Many folks recorded eye disease in their flocks, and two observers saw it in goldfinches and purple finches too.

Joyce and Phil Schaff of Chambersburg reported 9 purple finches, two of which had the disease, dozens of goldfinches, and only 5 to 6 house finches. Two of their house finches had conjunctivitis. Stan Kotala, who lives at the other end of our mountain, told me that he noticed an increase in purple finches at his feeders over the last five years and had had 12 in April. Charlie and Marge Hoyer, my closest neighbors on the mountain–three miles as the crow flies–had 6 to 8 house finches at their feeders last winter.

I hypothesize that, for the most part, these urban, suburban and farm-loving birds only stray to wilder places when their numbers are high. The nearest bird feeders to mine are probably two miles away in the valley. That’s not too far for house finches to range. Andrew Davis, who radio-tracked them in Ithaca, New York, from one backyard feeder to another, found that they could easily range from one to two miles a day.

Davis also studied the winter-roosting behavior of house finches and discovered that their roosts only contain house finches. They use the same conifers more than 30 feet tall as roosting trees night after night. House finches begin arriving in the roost area and gathering in nearby deciduous trees two hours before dusk. Their numbers increase until half an hour before dusk, and then each bird flies silently into the thickest and highest part of the conifer tree or trees, depending on the size of the flock, and don’t move or make a sound after settling down for the night.

It is their winter-flocking habit, as well as the long distance dispersal of juveniles that helped to quickly spread conjunctivitis. Also, because eastern house finches originated from a small number of released birds, they are highly inbred and have low genetic diversity, which may have made them more susceptible to the disease.

Scientists have been surprised at the longevity of the disease. Most diseases run their course in a few years once a large proportion of a population is eliminated as eastern house finches were. Instead, it has continued to spread across North America. In the winter of 2004, the North West house finch population experienced their first widespread epidemic of house finch eye disease. Here in the East, Cornell scientists estimate that five to ten percent of house finches now have conjunctivitis, but that it is no longer a dire threat to the species.

Researchers Andre A. Dhondt, who has been studying this surprising disease from the beginning, and Melanie Driscoll have learned that it rises at the end of summer and peaks in autumn. Then it declines to a mid-winter minimum, increases to an early spring peak, and returns to minimal numbers during the breeding season.

House finches still remain among the most common feeder species even though their flock size continues to fall, dropping to record or near-record lows in the East and North Pacific areas, as of the winter of 2004-2005, according to the reports from participants in Project FeederWatch.

I suppose that sooner or later a few house finches will find my feeders again. Next time I won’t take them for granted. If there is any lesson I’ve learned over my decades of nature-watching, it is that nothing remains the same.