• Scott Tansowny

Black-Backed Woodpeckers: Burned Forest Specialists

Updated: Apr 21

One of the most fascinating birds found in Alberta are black-backed woodpeckers. They are medium-sized woodpeckers with a length of 23 cm. They have sooty black backs, camouflaging them with the recently burned trees they are often found on; white underparts barred with black on the sides and flank; and a white stripe below their eye. The male has a bright yellow patch on its crown.¹

Male Black-Backed Woodpecker, Pacific Southwest Region USFWS from Sacramento, US [Public domain]

Black-backed woodpeckers are very specialized and mysterious woodpeckers, thriving in unique habitats and on very specific diets. Their populations are highly variable and extremely dependent on the habitat and food source they have adapted to survive with. This specialization means they are very susceptible to a loss of this particular type of habitat.


Black-backs feed on the larvae of wood-boring beetles and bark beetles. According to a Smithsonian Institute bulletin by Arthur Cleveland Bent, more than three quarters of their diet is wood-boring beetles. They feed by flaking off the bark of the tree with angled strikes of their bill in order to expose the holes of the wood-boring beetles and the channels of bark beetles.² If you’re searching for these woodpeckers be sure to look for trees with stripped off bark that signals the presence of this species.


The following video shows this unique feeding technique.


The populations of wood-boring and bark beetles, the main food source of black-backed woodpeckers, increase dramatically when presented with dead trees, typically killed by disease, windfall, or burns.³ This makes habitats such as recently burned coniferous forest or mature and overmature coniferous forests a prime area for this important food sources and, in turn, a perfect habitat for the woodpeckers to forage. In fact, as a 2009 Quebec study found, the black-backed woodpecker is almost exclusively found in mature forests that are at least 80 years old. As well, the study suggested that due to this reliance on a specific habitat, the black-backed woodpecker is a perfect indicator species for mature and old-growth lodgepole pine stands to help us better measure the health of these forests.⁴ Another requirement for breeding black-backed woodpeckers is live or dead trees large enough to excavate cavities for nesting, once again meaning that mature forests are a necessity.


Female Black-Backed Woodpecker from Oregon, Francesco Veronesi from Italy [CC BY-SA 2.0]

Threats to Habitat


Because of the dependence on wood boring and bark beetles for food and large trees for nesting, the largest threat to the black-backed woodpecker is loss of habitat.

Three threats to habitat discussed in a 2013 study in the Sierra Nevada and Cascade mountain ranges include thinning of forests, post-fire clear-cutting of burned forests, and fire suppression techniques. The study concluded that thinning an area of forest by 20%, clear-cutting 33% of burned forest, and a 50% increase in fire suppression would result in one third less primary habitat for black-backed woodpeckers.⁵ This study shows the large impact that our actions can have on this species.


A South Dakota study from 2014 found that the most productive habitat for these woodpeckers was habitats created by summer wildfire, followed by pine beetle infestations, and least productive was prescribed burns. In fact, only habitats created by summer wildfires had positive population growth rates.⁶ This study showed that prescribed burns and mountain pine beetle infestations, while valuable to black-backed woodpeckers, are not a replacement for summer wildfires. These are important findings because it goes against common thinking that fire suppression and prescribed burns are needed to effectively manage forests. While these are important in inhabited areas to protect communities, there is no substitute for the natural process of summer wildfires in the natural world.


Another threat to these habitats is salvage logging after wildfires. Salvage logging is when trees are harvested from a burned area in an attempt to recover some of the lost economic value of that area of forest. The key issue with this practise is that it is removing parts of the habitat that are critical for the black-backed woodpecker. One of these features is snags, dead or dying trees that are still standing. A 2009 study found a direct correlation between the number of snags and the populations of black-backed woodpeckers. They also found that the woodpeckers preferred snags that were at least 3 years old as those contained the highest numbers of wood-boring beetles.⁷ When we log these areas that appear to be of no use to wildlife, we are actually destroying an important ecosystem. We often associate live trees with the need of protection but forget the importance of dead trees.


Example of a Snag in Washington, By Walter Siegmund, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=18733979

The loss of old-growth forest is another threat to this species. These woodpeckers rely heavily on mature and overmature forests and losses to these through logging and development are a consistent threat to black-backed woodpeckers.


It is also important to remember that the black-backed woodpecker is not the only species impacted by these threats. Its reliance on a specific habitat makes it an effective indicator species for the health of this habitat. A reduction in the populations of black-backed woodpeckers signals a reduction in this type of habitat which can have far-reaching impacts on many other species of flora and fauna.


Conservation


This species is listed as “sensitive” in Alberta due to being vulnerable to loss of habitat. So what can be done?


It is important that this habitat type is recognized, protected, and incorporated into forest management strategies. Where possible it is almost always better to step back and let the forest manage itself. Time and time again when we get involved to try and “fix” a problem, our actions have negative unintended consequences. We need to look at this factor when planning fire suppression.


Another step to protecting this species is protecting mature coniferous forests. Old-growth forests are important for many species and thinning them or clearing them through logging is a large threat. Salvage logging needs to be minimized as well to ensure snags are present for this species to forage.


We need to ensure that we continue to protect large areas of boreal forest. These areas need to remain natural, wild, and unmanaged to keep habitats like this healthy and plentiful.


Every niche, every unique habitat has species that rely on it and we need to look to indicator species such as the black-backed woodpecker in order to conserve all species and habitats. So next time you come across a burned area of forest, take a minute to think about the importance of this habitat and if you look closely, maybe you’ll spot one of these amazing creatures.


1. Tremblay, J. A., R. D. Dixon, V. A. Saab, P. Pyle, and M. A. Patten (2016). Black-backed Woodpecker (Picoides arcticus), version 3.0. In The Birds of North America (P. G. Rodewald, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bna.bkbwoo.03

2. Bent, A. C. (1939). Life histories of North American woodpeckers. Order Piciformes. Bulletin of the United States National Museum.

3. Hoyt, J. S., & Hannon, S. J. (2002). Habitat associations of black-backed and three-toed woodpeckers in the boreal forest of Alberta. Canadian Journal of Forest Research, 32(10), 1881-1888.

4. Tremblay, J. A., Ibarzabal, J., Dussault, C., & Savard, J. P. L. (2009). Habitat requirements of breeding Black-backed Woodpeckers (Picoides arcticus) in managed, unburned boreal forest. Avian Conservation and Ecology, 4(1), 1-16.

5. Odion, D. C., & Hanson, C. T. (2013). Projecting impacts of fire management on a biodiversity indicator in the Sierra Nevada and Cascades, USA: the black-backed woodpecker. The Open Forest Science Journal, 6(1).

6. Rota, C. T., Millspaugh, J. J., Rumble, M. A., Lehman, C. P., & Kesler, D. C. (2014). The role of wildfire, prescribed fire, and mountain pine beetle infestations on the population dynamics of black-backed woodpeckers in the Black Hills, South Dakota. PLoS One, 9(4), e94700.

7. Bonnot, T. W., Millspaugh, J. J., & Rumble, M. A. (2009). Multi-scale nest-site selection by black-backed woodpeckers in outbreaks of mountain pine beetles. Forest Ecology and Management, 259(2), 220–228. doi:10.1016/j.foreco.2009.10.021

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