Tap tap tap…tap tap tap. I turn my head at the distinctive sound of a woodpecker on a tree, hoping to glimpse it. I see a black-and-white body, with its head moving rhythmically as it searches for food, peck peck, peck peck. But is it a downy or a hairy woodpecker? Despite over 15 years of studying birds all over the globe, I still pause to double-check this one. If you’re new to birdwatching, or even a seasoned veteran, you’re about to embark on one of the trickier identification quests. Let’s find out which is which!
The Bottom Line
Hairy woodpeckers are larger than downy woodpeckers, have proportionally longer beaks, and have pure white outer tail feathers (whereas downy woodpeckers have black spots). Hairy woodpeckers also drum faster than downy woodpeckers. This gives downy woodpeckers the perception of being more delicate than hairy woodpeckers. If you want to catchy way to remember the size difference, just think dainty=downy and huge=hairy!
The main differences between downy and hairy woodpeckers are:
- The downy woodpecker is smaller, whereas the hairy woodpecker is larger
- Downy woodpeckers have smaller bills, whereas hairy woodpeckers have larger bills
- The white outer tails feathers of downy woodpeckers have black spots, whereas hairy woodpecker outer tail feathers have no spots
Downy woodpeckers and hairy woodpeckers have very similar ranges throughout the US and Canada, though the hairy woodpecker’s range extends further south into Mexico and parts of Central America. Both species are also residents (non-migratory) throughout the year and brighten up the winter landscape in the northern part of their range. That also means that in most of North America, you have a high likelihood of encountering either species – making telling them apart even more important.
How to Tell Them Apart
These two species often stump birdwatchers, as they are very similar in coloration. There are three ways to visually tell apart these two species.
The first, and perhaps the hardest, is size. The smaller downy averages 6.5 inches (range 5.5-6.7 inches), whereas the larger hairy averages 9.5 inches (range 7.1-10.2 inches). However, it can be difficult to estimate size with one bird alone unless you have a lot of practice or you have something nearby to compare. So, if body size isn’t working for you, check out the bill. If you have a clear view of the head and beak, look at how long the beak is compared to the head. In addition to having a smaller body, the downy has a smaller bill – it’s less than half as long as the head. The hairy, in comparison, has a bill that’s about the same length as the head.
If you’re still struggling, or can’t see the beak, hopefully, you have a good view of the tail, specifically the outer tail feathers. In the downy woodpecker, there are black spots in the outer white tail feathers, while the hairy woodpecker has pure white outer tail feathers. However, there is variation in body coloration throughout the range of both woodpecker species; in fact, there are currently 11 subspecies of hairy woodpeckers and 7 subspecies of downy woodpeckers recognized.
In both species, the males are distinguished from females by having a red patch on the back of their head. Otherwise, sexes are identical.
Their call is another way to tell these species apart. The call of the downy is a rapid whinny, descending in pitch (ki-ki-ki-ki-ki), while the call of the hairy stays on one pitch. A downy also makes a high-pitched pik! which is not as sharp than the stronger peek! of the hairy. Hairys also have more beats when they drum compared to downies (average 24.9 vs. 12.7, respectively).
Both species generally use the same types of habitat, such as forests, woodlots, and river groves. Both will also come to suet feeders and are backyard birds that can be seen in suburbia. However, downy woodpeckers are somewhat more abundant overall and are more willing to utilize habitats near urban environments, making them more common to see on backyard feeders than hairy woodpeckers. The smaller size of downy woodpeckers means that they can forage on thinner branches and stems for food. This type of younger vegetation is prominent in disturbed areas found near residential developments.
Both species are mainly insectivorous. Like most woodpeckers, they are built for chiseling away bark and into wood, eating insects in all their life stages (eggs, larvae, pupae, and adults) in both live and dead wood. As a few examples, both species consume spruce bark beetles which can have population outbreaks that kill healthy trees; both species may increase in abundance in burned forests when wood-boring beetles become common; and the smaller hairy can land on goldenrod stems to eat the larvae in the galls. However, the two species do specialize somewhat in the strategies used for finding insects: hairy woodpeckers will excavate wood for insects more and downy woodpeckers will feed more often on the bark and in crevices. They will also eat berries and, as anyone with a backyard feeders knows, seeds and suet as well. They have also been reported – rarely – to feed on sap.
Downy woodpeckers are more curious and bolder than hairy woodpeckers, but hairy woodpeckers are more aggressive and attack downy woodpeckers. Downy woodpeckers are also more likely to be in mixed-species flocks, a behavior that lets them forage more efficiently since they spent less time being vigilant.
Both species are cavity nesters, and both sexes excavate the nest hole in a dead tree or dead part of a live tree. As you would expect from their larger size, hairy woodpeckers make larger cavities and entrance holes. Hairy woodpecker holes are also more oval-shaped (2 inches high, 1.5 inches wide) vs. more round for downy woodpecker holes (1-1.5 inches across). Both sexes incubate the eggs (downy woodpeckers lay 3-8 eggs, usually 4-5, and incubate for 12 days; hairy woodpeckers lay 3-6 eggs and incubate for 11-12 days) and feed the young (downy young fledge in 18-22 days while hairy young fledge in 28-30 days).
Other Similar Species
Woodpeckers and sapsuckers are two of the few groups of birds that climb upright on tree trunks and branches. Of the woodpeckers and sapsuckers, there are several species that look similar to the hairy and downy: three-toed, black-backed, ladder-backed, Nuttall’s, and red-cockaded woodpeckers, plus yellow-bellied and red-naped sapsuckers. That’s quite the list! To make the comparison easier, I’ve compiled a table to describe three places whether there are fairly large differences between our two focal species and the look-a-likes:
|Back pattern||Flank pattern||Wing pattern|
|Hairy woodpecker||White stripe||White||Partially spotted|
|Downy woodpecker||White stripe||White||Partially spotted|
|Three-toed woodpecker||Barred||Barred||Minimally spotted|
|Black-backed woodpecker||Black||Barred||Minimally spotted|
|Ladder-backed woodpecker||Barred||Barred||Completed spotted|
|Nuttall’s woodpecker||Barred||Barred||Completed spotted|
|Red-cockaded woodpecker||Barred||Barred||Completed spotted|
|Yellow-bellied sapsucker||Barred||Barred||Large white patch|
|Red-naped sapsucker||Black stripe bordered by barred||Barred||Large white patch|
You’ll notice that the downy and hairy woodpeckers are the only species with a white stripe down their backs, no barring (white) on their flanks, and mid-level spotting on their wings.
As two similar-looking species of woodpecker, one might expect that they are closely related to each other. Surprisingly, they are not each other’s closest relative. Instead, the similar coloration of the two species is due to convergent evolution. Both species are in Class Aves, Order Piciformes, and Family Picidae, but then they diverge. Hairy woodpeckers are in the genus Leuconotopicus, which includes the red-cockaded and white-headed woodpeckers, among others, while downy woodpeckers are in the genus Dryobates, which includes Nuttall’s and ladder-backed woodpeckers among others.
Because downy and hairy woodpeckers look so similar to each other but are each more closely related to other more dissimilar-looking species, this begs the question: if their similar plumage is not due to common ancestry, why do they look so similar? Once ancestry, ecology (habitat), and predation have been ruled out, mimicry is the most common remaining evolutionary mechanism. The idea centers around the theory of ‘interspecific social dominance mimicry,’ where one species gets benefits (usually access to food) by looking like an aggressive species.
So there are two ways this theory could work. One way is that downy woodpeckers look like hairy woodpeckers to reduce aggression from hairy woodpeckers themselves – but in fact, hairy woodpeckers do act aggressively towards downy woodpeckers, and so this idea is not supported.
Because the larger hairy woodpecker tends to be dominant in interspecific (between-species) interactions – it wins against 10 species and only loses to 2 – the other idea is that downy woodpeckers look like hairy woodpeckers to reduce aggression from other birds that already avoid the aggressive hairy woodpecker. This works if another bird, like a cardinal, sees a black-and-white bird approaching and assumes it was the aggressive hairy woodpeckers, and so leaves the food source, but in fact, the little downy woodpecker was the instigator and gains access to the food because it is mistaken for a hairy woodpecker.
This is the current theory why hairy and downy woodpeckers look so similar. In fact, the idea of interspecific social dominance mimicry has so intrigued evolutionary biologists in general that these two species are now used in a theoretical model in evolutionary biology for how mimicry evolves.
Answer: Catesby, the person who illustrated these birds in the early 1700s, described the downy as having soft feathers in the white stripe on its back and described the hairy as having more hair-like feathers. This is now reflected in their scientific names: the species name of hairy woodpeckers is villosus, which is Latin for ‘hairy,’ and for downy woodpeckers is pubescens, which is Latin for ‘pubescent’ or ‘downy.’
Answer: Both species still search for insects on and under bark during the winter, but they will also eat seeds, suet, and berries.
Answer: Yes, in North America, the downy is the smallest woodpecker we have.
These two species have challenged the identification skills of birdwatchers for a long time. Perhaps some are happy just knowing they have a black-and-white woodpecker in their yard, or they saw one hopping up a tree, but I enjoy knowing which species I have seen. With practice, you can tell these two species apart, and appreciate both the antics of the smaller downy and the dominance of the larger hairy as they go about their lives, foraging and flying. If you want to attract these birds to your yard, check out these articles on which birdfeeder to choose:
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- Fayt, P., Machmer, M. M., & Steeger, C. (2005). Regulation of spruce bark beetles by woodpeckers—a literature review. Forest Ecology and Management, 206(1-3):1-14.
- Fuchs, J.; Pons, J.M. (2015). “A new classification of the pied woodpeckers assemblage (Dendropicini, Picidae) based on a comprehensive multi-locus phylogeny.” Molecular Phylogenetics and Evolution, 88:28–37.
- Gill, Frank; Donsker, David; Rasmussen, Pamela, eds. (2020). “Woodpeckers.” IOC World Bird List Version 10.1
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- Leighton, G. M., Lees, A. C., & Miller, E. T. (2018). The hairy–downy game revisited: an empirical test of the interspecific social dominance mimicry hypothesis. Animal Behaviour, 137:141-148.
- Miller, E. T., Leighton, G. M., Freeman, B. G., Lees, A. C., & Ligon, R. A. (2019). Ecological and geographical overlap drive plumage evolution and mimicry in woodpeckers. Nature communications, 10(1):1-10.
- Moore, W.S.; Weibel, A.C.; Agius, A. (2006). “Mitochondrial DNA phylogeny of the woodpecker genus Veniliornis (Picidae, Picinae) and related genera implies convergent evolution of plumage patterns.” Biological Journal of the Linnean Society, 87(4):611–624.
- Nappi, A., Drapeau, P., & Leduc, A. (2015). How important is dead wood for woodpeckers foraging in eastern North American boreal forests? Forest Ecology and Management, 346:10-21.
- Ouellet, H. Comparative foraging ecology of downy and hairy woodpeckers (Aves: Picidae).
- Prum, R. O., & Samuelson, L. (2012). The Hairy–Downy Game: a model of interspecific social dominance mimicry. Journal of theoretical biology, 313:42-60.
- Stark, R. D., Dodenhoff, D. J., & Johnson, E. V. (1998). A quantitative analysis of woodpecker drumming. The Condor, 100(2):350-356.
- Sullivan, K. A. (1984). The advantages of social foraging in downy woodpeckers. Animal Behaviour, 32(1):16-22.
- Weibel, Amy C.; Moore, William S. (2005). “Plumage convergence in Picoides woodpeckers based on a molecular phylogeny, with emphasis on convergence in downy and hairy woodpeckers.” The Condor, 107(4):797–809.