Citizen-scientists in Minnesota are optimistic they can bring back the charismatic and declining Red-headed Woodpecker through habitat restoration
By Chet Meyers | Published: 4/1/2017
An older gentleman approached me at a recent Audubon chapter meeting. “Yep, I used to see plenty of them when I was a kid,” he said. “They hung around an old corn crib on our farm.”
Sadly, I have heard similar comments throughout my home state of Minnesota over the past few years. The old gentleman was correct; there used to be a lot more Red-headed Woodpeckers.
Since the 1960s, the species’ numbers have plummeted across most of its range. According to Minnesota Audubon, Red-headed Woodpeckers have declined almost 80 percent since the 1960s in Minnesota alone. They are also pretty much gone from our New England states, where, in the 1800s, a bounty was placed on the birds as they descended on, and cleaned out, farmers’ cherry orchards.
Numerous state breeding bird atlases and Christmas Bird Counts have documented the extent of the decline. The cause is a little more speculative. In the Upper Midwest, the drop correlates consistently with a loss of oak savanna habitat. Savanna is characterized by a flat, open understory interspersed with small clumps of living and dead oak trees. In Minnesota, over 98 percent of the original oak savanna is gone, mostly as a result of suburban development and intensive agriculture. Developers just love the land since it’s flat and has little water and few trees; there’s not much to do but just build homes.
For the past eight years, a small but energetic group of committed birders has been working to preserve and expand Red-headed Woodpecker habitat in the Upper Midwest. Through the group’s citizen-science research, we have learned a lot about the charismatic woodpecker and the habitat it needs to thrive.
The boldly marked bird is hard to confuse with other North American woodpeckers — even the poorly named Red-bellied Woodpecker. Both the male and female have almost identical red, black, and white plumage. The only way to distinguish gender is via DNA evidence.
Red-headed Woodpeckers are not shy, so, in one sense, they’re relatively easy research subjects, but they are cavity nesters and picky about habitat. Biologists refer to them as habitat specialists. In the Upper Midwest, two needs are essential: oak savanna with clumps of live and dead oak trees, and regular disturbance by fire.
Creating a savanna
We learned about the importance of frequent burning from biologist Rich King, the former naturalist at Necedah National Wildlife Refuge, in central Wisconsin. He had success creating an oak savanna out of what was pretty much an oak forest at the refuge. First he designated and preserved small clusters of live and dead trees. Then he chopped down the remaining trees and cleared the understory. Still, only a few birds showed up to inspect the new savanna. It wasn’t until a burning regime was initiated that things changed. The results were dramatic. Within three years of regular disturbance, 70 nesting pairs were present on the newly created savanna.
Why is burning so important? Most of us associate woodpeckers with pecking trees in search of insects, larvae, or grubs. Red-headed Woodpeckers, however, spend most of the spring and early summer catching flying insects. Their close cousins, the Acorn and Lewis’s Woodpeckers, do the same. The birds usually position themselves at the end of dead limbs and then either hawk insects (fly up) or stoop (drop down) to catch insects close to the ground. The thicker the understory, the more hiding places insects have. Regular burning keeps the understory low and makes insects more accessible.
Our Red-Headed Woodpecker Recovery Project initially considered building nest boxes (as had been so successful with the bluebird), but King convinced us it was more important to preserve and expand the oak savanna. The woodpeckers will excavate their own nest cavities if habitat is present.
With the help of 25 committed volunteers, the recovery project surveyed the entire state to discover the location of remaining healthy oak savannas where groups, or what we call clusters, of Red-headed Woodpeckers were present. (We define a cluster as three or more pairs in an area a quarter mile in diameter.) Individual pairs still remain throughout the southern and central parts of the state, but the pairs are scattered and often located in isolated telephone poles and a few remaining abandoned farmsteads. Few groupings or clusters remain.
Given this situation, it made sense to locate the remaining healthy groups of birds and then work with landowners and managers to retain, and hopefully expand, that habitat. Presently, groups of Red-headed Woodpeckers are holding their own in seven areas — four on state or federally owned and managed land, one on a private nature reserve, and two on golf courses. As natural oak savanna disappears, some birds have resorted to golf courses that are nature-friendly and have stands of red, white, or bur oak.
Learn more about woodpeckers
Key to our project is the cooperation of the University of Minnesota and its field station at the Cedar Creek Ecosystem Science Reserve, in East Bethel, just north of Minneapolis. The reserve encompasses over 5,400 acres of woods, wetlands, and oak savanna and is home to 30-40 breeding pairs of beautiful and raucous woodpeckers. Eight years of research at Cedar Creek has taught us a lot about the bird, its preferred habitat, and what we might do to expand its numbers.
So what have we learned? Red-headed Woodpeckers feed primarily on insects in the spring and early summer. The remainder of the year, however, they are opportunistic feeders — that is, not very picky. As the summer progresses, they begin to feed on fruits and berries. Then, in the fall, when the acorn crop matures, they eat both acorns and the grubs that are often inside them. Acorn crops are cyclical. In good years, some birds will cache the nuts to eat in winter. If the birds do not overwinter, we assume they move only far enough south to secure territory and food.
How and when the birds decide to overwinter, or to leave, is a mystery. In 2012, 180 mature and juvenile woodpeckers were in our 400-acre research area. The acorn crop was not good, but we were amazed at how rapidly the birds left. All but two departed in two or three days in the second week in August. How was the exit coordinated? Did the birds communicate with each other? In contrast, only a few woodpeckers flew away in August 2015, while 72 chose to overwinter. Do they not only sense the health of the acorn crop but also have clues to the severity of the winter? We are learning much, but the mysteries of overwintering still remain.
Most birders know that Red-headed Woodpeckers are cavity nesters. What may be less known is that, generally, they are high nesters. For more than 200 nests that we have documented, the average cavity height was about 26 feet, and our highest nest was 65 feet up. The loftiness helps explain why the birds fledge so many young; 75 percent of nests produce at least one fledgling. High nests discourage predation. Nesting preference is for dead trees or dead limbs in live trees. We have recorded successful cavities in the trunks of living oak and live aspen, but a survey of all nests shows the woodpeckers clearly prefer to nest in dead wood.
Egg-laying begins in early May, and the average clutch size is four to five eggs. It takes about 12-14 days for eggs to hatch and another 26 days until juveniles are old enough to fledge, for a total of about 40 days from egg-laying to fledging. On average, only two of the brood will survive to fledging. We are studying why brood success (that is, the number of fledglings per total eggs laid) is a little less than 50 percent, but our data are consistent with other studies and historical writings. It’s just another mystery waiting to be solved.
One rather nasty piece of news: Red-headed Woodpeckers are messy nesters. They do little, if anything, to keep their nests clean. Indeed, in one case, the male died while in the nest cavity, and the female laid her eggs on top of his carcass.
Our research methods include color-banding and then observing nesting success with a narrow miniature camera mounted on an extendable pole. Careful monitoring of our work has shown little if any negative impact on the birds’ activities. The woodpeckers are not shy. In fact, once they recognize our surveyors, the birds often follow them around looking for a handout, as we stock scattered feeding stations with peanuts.
We have used both mist-nets and Potter traps (small cage-like traps) to capture birds. The first time we used a cage trap, we baited it with sunflower seeds and peanuts and inadvertently tossed in a few macadamia nuts that one of our researchers was snacking on. The first woodpecker to arrive immediately seized upon the macadamia nuts and was trapped. Since ours is a low-budget project, we quickly decided that we could not afford to use macadamia nuts regularly; the birds would have to settle for peanuts.
We have banded more than 170 Red-headed Woodpeckers with both metal numbered federal tags and colored plastic bands. We use six different colors, which afford us hundreds of possible combinations, so we can identify every bird from a distance. The first thing we learned, following our initial banding efforts, was that many of our birds return to the Cedar Creek savanna year after year. That may not sound stunning, but little, if any, published research demonstrates such site fidelity.
The first year, we banded 50 birds; none overwintered. The next spring, 17 of the banded birds returned. Recapture proved that we had banded them the previous spring. In addition, we have documented examples of nest-tree fidelity — that is, birds returning to either the same tree or one near it the following year. We are still gathering data, but we have also seen examples of year-to-year mate fidelity.
Red-headed Woodpeckers are often portrayed as territorial birds, and they are, but at Cedar Creek they also exhibit a clear colonial nature. All of the birds we have studied have been found in less than 400 of the reserve’s 5,400 acres. The reserve includes a few hundred additional acres of savanna, but they have not been burned regularly. This tells us that if adequate habitat, low understory, and food are present, the woodpeckers tend to cluster.
They do, however, remain territorial vis-à-vis their particular nest site but apparently don’t need much elbow room. We have recorded nests as close as 30 feet to each other. The birds will defend that perimeter but, other than that, seem content to have neighbors nearby. The size of the reserve’s colony varies between 30 and 40 verified nests per year.
Our research is important, but so, too, is our advocacy work across the region. We share our findings with agencies and landowners on whose land groups of birds persist. The work has been gratifying, as state and federal agencies have made commitments to expand oak savannas and to conduct regular burning of the understory. Recently, Sherburne National Wildlife Refuge, northwest of Minneapolis, agreed to recreate oak savanna on two parcels of forested land. Thanks to their efforts, Red-headed Woodpeckers were verified nesting at the refuge last year for the first time in 10 years, and this year, observers documented additional birds on another savanna area and on the auto-tour road. We have also helped with burns and serve as consultants for the Belwin Conservancy, a non-profit organization that is recreating oak savanna on the nearly 1,400 acres of permanently protected land it owns in Afton and West Lakeland townships, east of Minneapolis.
While most of our efforts focus on small clusters of woodpeckers — three to six pairs — a few years ago we discovered a concentration that may be even larger than the one we are studying at Cedar Creek. The colony is in an unlikely place — Camp Ripley, one of the largest National Guard training centers in the Midwest.
The facility covers 53,000 acres near Little Falls, in the central part of the state. Within it are two large firing ranges (totaling nine square miles) that are burned every year so troops can fire armaments and fighter planes can drop bombs. This may not sound attractive to you, but it is to the woodpeckers. Because of the yearly burns and many broken trees, the birds have set up shop in the firing ranges.
Forbidden to take one step onto the grounds due to unexploded ordinances, we can only drive two roads that circumnavigate both ranges and have to locate woodpeckers using spotting scopes and binoculars. On our first visit, we saw numbers of adults and juveniles. We can only guess how many pairs are present and what it takes to raise a brood within an active firing range. Still, our cursory surveys reveal that the birds are doing quite well. As an old fishing buddy used to say, “Go figure!”
Although we are only in the fledgling stage of research and habitat-recovery work, we are optimistic that something can be done to stop the decline of the Red-headed Woodpecker and to increase its numbers. A certain type of savanna habitat is essential, along with regular burning to sustain an open understory. In recent years, as the Cedar Creek staff has expanded the burning regime, the woodpeckers have moved into the newly burned territory and begun nesting.
It may be difficult to create new groups or clusters, but if an area has a history of hosting Red-headed Woodpeckers, and a few pairs remain, it is realistic to enhance and expand that habitat through land acquisition, selective tree cutting, and regular burning regimes.
Nothing is guaranteed, but we believe the wisdom from the movie Field of Dreams holds: If you build it, they will come.
Chet Meyers is a retired professor at Metropolitan State University, in St. Paul, Minnesota, and the chair of the Red-headed Woodpecker Recovery Committee of the Audubon Chapter of Minneapolis.
This feature article is from the April 2017 issue of BirdWatching.
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