History of Red-headed Woodpeckers Before 2012 at CCESR
The highest concentration of known nesting Red-headed Woodpeckers (RHWO) in Minnesota occurs at the Cedar Creek Ecosystems Science Reserve (Cedar Creek) in northern Anoka County. (Higher numbers may nest at Camp Ripley, but they cannot be verified because of safety and security concerns on the military post.)
There were about 60 breeding pairs in 2012 and 31 pairs in 2013 near the southeast corner of Cedar Creek. Even more impressive, we reported 56 RHWOs on the 2011 Christmas Count, vastly more than any other count in the region. (However, all of the woodpeckers migrated and none were present for the 2012 Christmas Count.) The Red-headed Woodpecker Recovery (RhWR) project would dearly love to have many such areas elsewhere in Minnesota and adjacent states. So, we have been trying to determine what makes Cedar Creek so attractive to the birds.
All RHWO nests at Cedar Creek in the last several years have been in or adjacent to areas subjected to prescribed burns. Periodic prescribed burns were begun in 1964 with the aim of re-establishing oak savannah habitat and without any thought about RHWOs. Such burns appear critical for maintenance of the high breeding population at Cedar Creek. There is a positive correlation between nest density and burn frequency.
The distribution of RHWOs at Cedar Creek has changed over the years. Dr. Jim Howitz first visited Cedar Creek in summer 1975 and paid little attention to the woodpeckers he saw because he was studying Black-capped Chickadees. However, he kept notes of the other bird species encountered and tried to reconstruct a “history” of RHWOs at Cedar Creek.
Prior to its acquisition by the University of Minnesota and Minnesota Academy of Sciences beginning in the 1930s, Cedar Creek consisted mostly of woodlands, marshes, bogs, and farmsteads. According to the real old-timers talked to, RHWOs were common on the farms. They nested in scattered trees, caught flying insects, and fed on acorns and corn. Evidently, RHWOs were present at Cedar Creek before the regimen of prescribed burns was started. Jim first noticed them at Cedar Creek in “savannah” habitat in the abandoned farmstead near the intersection of Anoka County Roads 24 and 26 and the Peterson farm at County Road 24 and East Bethel Boulevard. It is likely that no more than three pairs were in each of these areas. He never saw any RWHOs in these areas after 1988. These areas look like reasonable RHWO habitat today, but it lacks sufficient dead trees to attract the birds.
A third area with perhaps several pairs was northwest of Fish Lake along both sides of County Road 76. They nested in the aspens and birches along the marshes and in the oaks south of the road. These woods have been on a ten-year burn cycle. Apparently, this has not been often enough to open the woods to the liking of the woodpeckers. This is now a closed canopy woods and to the eye totally unsuitable for RHWO’s. These woods were scheduled to be burned in spring 2014. We will see if the birds use it in the years after the burn. The disappearance of RHWOs from this area suggests that frequent burns are needed to maintain suitable habitat.
By 1978 Dr. Howitz noticed RHWOs west of Durant Street, in what is now the most concentrated nesting area. By 1989 the pattern of occupancy we see today was established. There were nesting pairs south of Fish Lake, west of 233rd Street, and along Durant Street.
Burn compartment 409 along County Road 26 was left unburned as a control until about 1998. For the first few years after it was burned the woodpeckers nested in aspens that had been damaged or killed by the fires. Nearly all the aspens there are gone now, and the woodpeckers nest in trees with harder wood.
A satellite group of one to three pairs of RHWOs has been nesting in the savannah known as Field D for several years. This area is about half a mile northwest of the main RHWO breeding area. A second such group has been nesting in the Davis plots about a mile west of the main area.
Since 2006 areas along the west side of East Bethel Boulevard have been burned annually (weather permitting). Four pairs of woodpeckers nested in these areas in 2012 and three pairs in 2012. With oak wilt and burning in most years, the breeding habitat of RHWOs west of East Bethel Boulevard should improve and we expect that many pairs will nest there. All of the areas at Cedar Creek where Red-headed Woodpeckers (RHWO) have been breeding in recent years are still suitable habitat. Eventually, the burning will eliminate the large northern pin oaks in some compartments, and the woodpeckers may need to move elsewhere. Burn compartments 105 and 108 have abundant regrowth of hazelnut and sapling northern pin oaks, other bushes, and vines. Although RHWOs breed in these areas, the habitat is probably not optimal. The birds breed in all of the burned savannahs at Cedar Creek, despite obvious differences in the density of live trees, dead trees, and ground cover. They do not breed in the adjacent Allison Savanna, though Jim found nests there in 1988 and 1989.
Red-headed Woodpeckers at Cedar Creek appear to have nested in farmsteads decades ago, and then shifted to fire-maintained savannah where they now nest exclusively.
For the past two breeding seasons, RHWOs that were breeding at Cedar Creek for the first time did so exclusively in areas that had just been burned within a few weeks. It appears that the birds are attracted to the open blackened ground with scattered live and dead trees. If the Red-headed Woodpecker Recovery (RhWR) project attempts to attract woodpeckers to new areas, controlled burning may prove crucial.
Dr. Jim Howitz
