Written by Bennett van Hoff - Editor: Anastasia Eginoglou
If you are lucky enough to have wandered in the North American woodlands, anywhere between Portland, Maine and Oregon, you may have seen trees that seem to have been attacked. There are wood chips littering the ground around the tree, scattered soft mulch which conjures images of a suburban rose garden, and the tree itself is full of massive holes. If these holes are rectangular, you have seen a tree that has been pecked apart by the magnificent Pileated Woodpecker.
It is only the largest of the North American woodpeckers still around today, with only the extinct Ivory-Billed woodpecker in competition. The size and shape of the hole that they create, and the red cap that they have all make this bird very distinct, although it may remain difficult to spot due to their rarity and general shyness. The trees with mulch surrounding them may be nest sites, which is where the young would be found. The male and female roost in different holes, although they remain in the same tree. The size of the bird makes sharing one hole impossible; the separation makes it more difficult for predators to choose the right hole while providing multiple entrances and exits to make escape even easier.
The relative violence with which they create their holes makes for a wonderful woodland soundscape, and they will also drum on trees to claim their territory. The holes they create to raise their young in are used for one year, and then the birds will abandon them. These empty roosts become homes for owls, bats, and entrance points for fungi to colonize old trees. While nesting, Pileated woodpeckers will even tolerate smaller bird species that join them and build their own nests in the large caverns that the woodpeckers have created. They are more than just another species on the list to improve biodiversity: their presence can increase the biodiversity of the area by providing space for other species to inhabit.
They prefer older trees to dig nests into, which requires older forests. The logging of the 1800s and 1900s left much of their ancient territory void of suitable trees to nest in, and so, their populations declined. Their preference for older trees, especially those with dead branches or entirely dead trees, also limited their space for roosting, as these trees are often torn down due to safety concerns. As logging and the lumber industry spread across the US-Canadian border, the spaces left for Pileated woodpeckers dwindled. The lumber industry fueled the growth of American cities, which are far too busy and notably treeless for the woodpeckers to find homes.
The large cities do, however, create suburbs.
As people in the 20th century began to tire of the busy city life and move outside of the cities, where they could have a larger home and a small piece of land, there were areas of forest that were not logged to provide recreation for those living in the suburbs. While they are not the sprawling wild forests that once covered this area, they are present, and some of the trees here have begun to age. This is when the adaptable pileated woodpeckers moved in.
The population near Seattle, in the Northwest part of the US, has been studied, and several successful breeding pairs have been found in small forest fragments near the large city. In Illinois, a way different region, the birds were rare not long ago but have been rebounding in population size and density. Where once they required 300 acres to breed and roost, they will now do the same with 150 acres. This adaptability of theirs has caused their numbers to gradually increase, and they can now be found all over their traditional range, in new and surprising areas. Their ability to dig into living trees helps them to make homes where other woodpeckers cannot, and when they do this, they also create habitat for other species to move into, later on. Woodpeckers are ecosystem engineers, creating living space for many species of ducks and owls, bats, insects, and they provide the pathway for heart-rot fungus to enter older trees. The holes that they create are not damage, but a space for biodiversity to root in a tree, whether it be in a forest or a suburb.
Pileated woodpeckers eat nuts and fruits, but the majority of their diet comes from digging into trees and finding insects. They are specialists at finding carpenter ants, and feast mainly on them, as well as other insects that burrow into trees. In recent years, it has been observed that when Emerald Ash Borer infest a forest, the Pileated Woodpecker populations increase dramatically, as they feed on these beetles. The Emerald Ash borer beetle is a well-known and hard-to-deal-with invasive species that destroys ash trees. This is an example of how nature can be used to protect nature, fueled by the adaptability of Pileated woodpeckers. Caring for these birds is a step on the way to successfully caring for other animals, and after all, the entire ecosystem.
The complete restoration of ancient landscapes is almost certainly not going to happen. However, the Pileated woodpecker is a good reminder that we can still work with nature and restore parts of it, inviting it closer to our homes. Providing areas of tree cover should be a part of basic urban planning, and allowing some of these trees to age may provide shelter for a surprising number of species. The Pileated woodpecker is not known for being bold, often avoiding human contact, so the presence of these birds in suburban landscapes shows that nature will adapt if we meet it halfway.
To provide space for the woodpeckers involves little more than caring differently for trees. Often, as suburban trees age in the suburbs they are removed. This is to avoid them falling onto a home, across a driveway, or into the road. The complete removal of these trees is not always necessary, however. A problem branch with water damage at the base of the branch is often treated with removal of the whole tree, but the branch may be the only dangerous part. The entire branch does not even really need to be removed, only the parts that add too much weight or hang over an area that should not have a branch crash down on it. There are many ways to ensure that trees are safe without removing them completely, and this is all that needs to be done to keep the woodpeckers and their associated biodiversity around.
References:
Pileated woodpecker. American Bird Conservancy. (2020, June 24). https://abcbirds.org/bird/pileated-woodpecker/#:~:text=The%20widely%20distributed%20species%20occurs,only%20two%20subspecies%20are%20recognized.
Aubry, K. B., & Raley, C. M. (2002). The Pileated Woodpecker as a Keystone Habitat Modifier in the Pacific Northwest¹. In Proceedings of the Symposium on the Ecology and Management of Dead Wood in Western Forests: November 2-4, 1999, Reno, Nevada (Vol. 181, p. 257). US Department of Agriculture, Forest Service, Pacific Southwest Research Station.
Koenig, W. D., & Liebhold, A. M. (2017). A decade of emerald ash borer effects on regional woodpecker and nuthatch populations. Biological Invasions, 19, 2029-2037.
Tomasevic, J., & Marzluff, J. (2020). Roosting, reproduction, and survivorship of Pileated Woodpeckers (Dryocopus pileatus) in a suburban setting. Avian Conservation and Ecology, 15(1).