Knock Knock – All About Woodpeckers

Woodpeckers are among our most-loved birds, but how much do you really know about them? There are 22 types of woodpecker in North America – can you guess which one inspired Woody Woodpecker? Hint: it’s not what you probably think…read on to find out the truth.

Woodpeckers are tree-dwelling birds that belong to the family Picidae, which also includes sapsuckers, flickers, yellownapes, wrynecks, flamebacks and piculets. Only woodpeckers, flickers and sapsuckers are found in North America.

As cavity nesters, Woodpeckers are considered “keystone species” (meaning that other wildlife depend on them) partly because their nest holes become homes for small mammals and many other species of birds including small owls and cavity-nesting ducks such as the Bufflehead.

There are 22 living species of woodpecker in english-speaking North America along with possibly one other species, the Ivory-billed Woodpecker, which is almost certainly extinct.

Woodpeckers are not songbirds, but don’t mention that to this cheery little Red-headed Woodpecker.

 

Evolution and Classification

Woodpeckers – in fact, birds in general – are poorly represented in the fossil record, which makes tracing their origins difficult. However, the few fossils we do have seems to indicate that the Picidae (woopecker family) are thought to have evolved about 50 million years ago in Eurasia.

The earliest woodpecker fossil is thought to be over 25 million years old and was found in France. The oldest New World woodpecker fossil is a Piculet feather fragment preserved in amber from the Dominican Republic, about 23 million years old. Most other woodpecker fossils come from times much closer to the present day.

The most recent woodpecker fossil find was in Africa in 2012 and dates to 3 to 5 million years ago. It was related to present-day North America and European woodpeckers This is the oldest woodpecker ever found in Africa, and was named Australopicus nelsonmandelai to honor Nelson Mandela

Definitive scientific classification of woodpeckers has proven to be a slippery and contentious problem. For example, scientists can’t agree on how many species of woodpeckers exist, but the total number is around 230 worldwide.

However, we can say that woodpeckers belong to:

Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Piciformes
Family: Picidae

Classification based on appearance/anatomy, behavior and ecology has been used in the past but modern DNA sequence studies have thrown a wrench into all that. DNA studies indicate that even though they may have similar plumage and make their living in very similar ways, woodpeckers that appear to be closely related most likely evolved their attributes independently based on similar ecological selection pressures.

Today members of the woodpecker family are found all over the world except for polar regions, the oceanic islands New Guinea, New Zealand, Australia and Madagascar.

Size Extremes

Smallest Woodpecker

Bar-breasted Piculet by Joe Tocias courtesy of the Internet Bird Collection

The smallest member of the woodpecker family is the Bar-breasted Piculet, Picumnus aurifrons. Native to South America the Bar-breasted Piculet is only 8 cm (3.5 in) long and weighs only 7 grams.

There’s a hummingbird bigger than that! (The Giant Hummingbird Patagonia gigas, also South American, is about the size of a starling.)

Biggest Woodpecker

Pileated woodpecker

The Pileated Woodpecker Drycopus Pileatus, which at up to 49 cm or 19 inches long and a weight of up to 400 grams (almost a pound), is about the size of a crow, is the largest woodpecker in eastern North America, the Great Lakes area, Canada’s northern forests and parts of the Pacific coast. Two very similar looking species were larger – the Imperial Woodpecker and the Ivory-billed Woodpecker, but both are considered most likely extinct.

 

In North America

Largest Woodpecker

Pileated Woodpecker Drycopus pileatus

Smallest Woodpecker

Downy Woodpecker Picoides pubescens 

Most Widespread Woodpecker

Northern Flicker Colaptes auratus  

Most Unusual Woodpecker

Lewis’s woodpecker

Lewis’s Woodpecker Melanerpes lewis, spends about 75% of its time in summer catching insects on the fly instead of excavating for boring insects as other woodpeckers do. In fall, it gathers corn (but not other grains) and picks acorns and other nuts right off the tree. These are its primary food for the winter and spring until insects are available again. But you won’t see it much in winter – it’s one of the few woodpeckers that migrate.

 

 

Funniest Woodpecker

Woody Woodpecker
Woody

The beloved cartoon character “Woody Woodpecker” is often thought to be based on the pileated woodpecker but according to his creator Walter Lantz, Woody was in fact inspired by the acorn woodpecker, which looks nothing like Woody.

 

 

Unique Characteristics

What makes a woodpecker a woodpecker? They are distinguished from other birds by:

  • Extra long tongues – and I do mean EXTRA long!
  • Pick-like beaks, short legs and stiff tails which they use to brace themselves while pecking.
  • Distinctive pecking, drumming and drilling behaviors and sounds
  • Most woodpeckers have two toes facing forward and two facing backward

Woodpecker Tongues

Woopeckers mostly have (very) long tongues that are barbed at the end like miniature fishing spears. When they use their tongues to explore their excavations, their extra-sticky saliva helps hold onto their prey.

What do I mean by “long tongues”? Long enough that when not in use it wraps right around the bird’s heads – inside their skulls! Okay, technically most of it’s not their tongue. It’s actually the hyoid bone, as MIT Professor Lorna Gibson explains below:

Beaks

Since the woodpecker’s feeding strategy depends on being able to pierce wood and bark, all woodpeckers have straight, sharp beaks well-suited to their purpose.  Their beaks strike wood with up to 1500 times the force of gravity (1500G) without harming the bird. By comparison, a mere 100G would kill a human being. So why doesn’t it kill the woodpecker

The bird’s skull shape and angle help the force of impact spread over a larger area of the brain instead of focusing in one place. Strong neck muscles help absorb the shock.

Research has also shown that the woodpecker’s skull and lower jaw change shape at the microscopic level to help absorb the impact of its drilling. Interestingly, a woodpecker’s lower beak has more hard tissue than its upper beak. This harder tissue helps direct kinetic energy down through the lower beak and into the powerful neck muscles.

Distinctive Sounds

Woodpeckers do have various calls but they are not songbirds. While songbirds use their actual songs (not calls) to claim territory and attract mates, woodpeckers use a distinctive type of pecking to accomplish the same things. It’s called “drumming” – a rapid hammering on anything that will make a good noise, including metal signs and poles, house gutters, siding and chimneys. Each species has its own specific drumming style, and can probably recognize individual birds by the way they drum.

Woodpeckers look for prominent, exposed places from which to drum and call. Drumming can be heard for long distances and some creative woodpeckers make pests of themselves by finding extra loud methods, like this one (make sure you have your speakers turned on)


Woodpeckers, both male and female, start drumming for mates and territory in late winter. Drumming can carry on until about the end of June.

Woodpecker calls range from sharp, high-pitched squeaks to chatters, twitters, screams and wails.

Woodpecker Toes

Most woodpeckers are “zygodactylous”, meaning that that they have have two toes facing forward and two toes facing backward, unlike most songbirds which have three toes in front and one in back. You can see the backward-facing feet clearly in the top image. Four-toed woodpeckers can rotate their outer back toes to the side in order to climb up a tree.

Black-backed woodpeckers and American three-toed woodpeckers are exceptions to the four-toes rule: these woodpeckers have only three toes. They’ve lost the inner rear toe, and the remaining back toe doesn’t rotate.

Woodpecker Tails

It takes a lot of force to peck a hole into the wood and bark of a tree, and woodpeckers use their legs and tails to brace for the impact. Since bird tails aren’t long and muscular, a woodpeckers’ tail feathers need to be much stiffer than normal feathers to provide strong support. Typical bird feathers have a hollow rachis or central spine but the feathers in a woodpecker’s tail are filled with a foam-like form of the keratin that makes up the whole feather.

Woodpeckers also use their tails when feeding and may prefer feeders that have tail boards.

 

Woodpecker Plumage

Most North American woodpeckers are black, red and white with the exception of the Colaptes or flicker group, which usually have brown or green back and wings with black bars and a beige to yellowish underside with black spotting or barring and gorget.

Woodpecker plumage does not change for breeding season. Male woodpeckers are usually more colorful than female woodpeckers but in most species the differences between male and female plumage are small.  One notable except is the Williamson’s sapsucker, in which the male and female are, er, markedly different.  They are shown below, with the male on the left. (Photos by Sally King, US National Park Service.)

Some woodpeckers exhibit minor color changes as the age from juveniles to adults. The changes mainly take the form of movement or expansion of red head markings.

Juvenile molting occurs over an unusually long period of time, and can take up to four years for all of the flight feathers to be replaced with their adult forms.

Unlike other birds, woodpeckers do not have downy feathers.

Woodpecker Diet

A woodpecker’s natural diet is beetle larvae, spiders, ants including carpenter ants, and other bothersome insects. Woodpeckers have proven to be particularly valuable for keeping the invasive emerald ash borer under control.

They are also known to eat small vertebrates such as frogs, lizards, small fish, nestling birds and bird eggs and have been known to crack open beehives in search of honey.

Most woodpeckers will spend their lives spiraling up and down trees in search of insects. The northern flicker is the only woodpecker that regularly probes the ground for ants and other yummy items.

Some woodpeckers will excavate large holes to expose carpenter ants, but other foraging methods including scaling bark, probing crevices and plucking insects from the ground or from leaves.

Feeding Woodpeckers

Woodpeckers will come to bird feeders, especially feeders with a place to brace their tails against. They enjoy suet, peanuts, tree nuts, mealworms, sunflower seeds, fruit and – hummingbird nectar.

Woodpecker Lives

Mating and Breeding

Most woodpeckers are loners outside the breeding season and monogamous while breeding, with one pair tending each nest.

Most woodpeckers are monogamous but some (the Acorn and Red-cockaded woodpeckers), breed in clans and nest communally with non-breeding adult relatives helping to raise the young.

Mating usually begins with courtship, including dancing. Woodpecker dances involve a little wing and tail flicking and a lot of pointing, in which the beak is raised up and waved about like a miniature conductor’s wand. Here’s a couple of downy woodpeckers going at it (ignore the corny music):

 

Nesting

Most woodpeckers excavate a new nest every year and normally raise only one brood. Nesting season runs from early March through early August with slight variations depending on species. Males excavate the nest cavity, incubate the eggs overnight and help with feeding the nestlings. Both sexes work to keep the nesting chamber clean by taking fecal sacs away from the tree for disposal.

Although many woodpeckers will use a nesting box if you offer one, the Yellow-bellied sapsucker and Pileated woodpecker still need a nice tree to call home.

 

Eggs

Woodpecker eggs are pure white, laid in clutches of 3 to 8 eggs and are incubated for about two weeks.

 

Nestlings

Woodpecker nestlings hatch stark naked, with closed eyes. But that doesn’t stop them from being noisy! Their frequent chugging calls can be heard outside the nest chamber.

These babies have a better chance of survival than the young of birds that nest in the open, thanks to the deep, snug hidden nest cavities that deter most predators.

 

Migration

Most woodpeckers don’t migrate, but the Yellow-bellied Sapsucker breeds and summers across Canada, eastern Alaska and the northeastern United States, then heads south to winters in the southeastern United States and further south. The north-most populations of the northern flicker, red- breasted and red-naped sapsuckers, Lewis’ woodpecker and Williamson’s sapsucker all move south for the winter.

Despite the fact that most woodpeckers and allies stay put for the winter, they are all protected under the Migratory Birds Treaty Act.

 

Woodpeckers Play a Critical Role in Forest Biodiversity

Woodpeckers are more important to their ecosystems than their numbers might suggest. They are keystone species that many other organisms depend on for survival and thriving.

Woodpecker activities, especially those of the Pileated woodpecker   Drycopus Pileatus, help other species in their habitat by providing foraging opportunities, controlling insect populations, speeding up the process of forest decay/nutrient recycling, and spreading the important heart-rot fungus Phellinus tremulae. This fungus creates hollows in live trees and softens wood which is essential for cavity-nesting birds that excavate, such as nuthatches, chickadees and other woodpeckers.

Old woodpecker nests (especially northern flicker nests) provide new homes to many generations of other cavity-nesting birds, mammals and invertebrates that aren’t equipped to excavate wood. Other species also use old woodpecker nests to store food. Even woodpecker foraging can produce deep enough cavities to benefit other species.

Woodpecker predation is also key to controlling bark beetles (reducing their occurrence by as much as 98%) and wood-boring beetles. In Texas, woodpecker predation has significantly reduced populations of the southern pine beetle, and in the East and Midwest, they are gobbling up about 85% of emerald ash borers, an introduced species that has destroyed thousands of ash trees.

Red-naped sapsuckers drill sap wells into spruce, aspen and shrubby willow trees and accumulating sap feeds over 40 other species including hummingbirds.

Studies suggest that the closely-related Yellow-bellied sapsuckers foraging determines the northern breeding limits and the spring arrival of both the ruby-throated and rufous hummingbirds

When woodpecker populations disappear, so do many other species which is why woodpeckers can be used as general indicators of forest biodiversity.

Habitat changes have a huge impact on woodpeckers, most of whom rely on trees living and dead for foraging and excavating cavities. Modern forestry practices such as removing dead wood and fire suppression, along with firewood cutting, road construction and urban and agricultural development reduces the amount of suitable woodpecker habitat and causes their decline.

USA Woodpecker Species by Region

North East

  • Downy woodpecker
  • Three-toed woodpecker
  • Pileated woodpecker
  • Hairy woodpecker
  • Northern Flicker
  • Yellow-bellied sapsucker

   Midwest

  • Downy woodpecker
  • Pileated woodpecker
  • Northern Flicker
  • Red-bellied woodpecker (uncommon)
  • Hairy woodpecker

Southeast

  • Hairy woodpecker
  • Downy woodpecker
  • Red-cockaded woodpecker
  • Red-bellied woodpecker (uncommon)
  • Red-headed woodpecker
  • Pileated woodpecker
  • Yellow-bellied sapsucker

   South West

  • Acorn woodpecker
  • Hairy woodpecker
  • Downy woodpecker
  • Ladder-backed Woodpecker
  • Red-cockaded woodpecker
  • Red-headed woodpecker
  • Red-bellied woodpecker
  • Lewis’ woodpecker
  • Arizona woodpecker
  • Gila woodpecker
  • Golden-fronted woodpecker
  • Northern flicker
  • Gilded flicker
  • Yellow-bellied sapsucker
  • Red-naped sapsucker
  • Williamson’s sapsucker

Mountain

  • Downy woodpecker
  • Pileated woodpecker
  • Nuttall’s woodpecker
  • Northern Flicker
  • Hairy woodpecker
  • Arizona woodpecker
  • Ladder-backed Woodpecker (southern area)
  • Three-toed woodpecker
  • Black-backed woodpecker
  • Williamson’s sapsucker
  • Red-naped sapsucker

   Pacific (West)

  • Pileated woodpecker
  • Northern Flicker
  • Hairy woodpecker
  • Acorn woodpecker
  • Downy woodpecker
  • Red-breasted sapsucker
  • Lewis’ woodpecker
  • Black-headed woodpecker
  • White-headed woodpecker
  • Three-toed woodpecker
  • Black-backed woodpecker
  • Williamson’s sapsucker
  • Red-breaster sapsucker
  • Red-naped sapsucker

Alaska

  • Northern flicker
  • Downy woodpecker
  • Hairy woodpecker
  • Three-toed woodpecker
  • Black-backed woodpecker
  • Yellow-bellied sapsucker

 

Canadian Woodpecker Species by Region

Maritimes

  • Northern Flicker
  • Downy woodpecker
  • Hairy woodpecker
  • Three-toed woodpecker
  • Black-backed woodpecker
  • Pileated woodpecker
  • Yellow-bellied sapsucker

Central Canada

  • Northern Flicker
  • Pileated woodpecker
  • Downy woodpecker
  • Hairy woodpecker
  • Three-toed woodpecker
  • Black-backed woodpecker
  • Yellow-bellied sapsucker

Prairies

  • Northern Flicker
  • Pileated woodpecker
  • Downy woodpecker
  • Hairy woodpecker
  • Three-toed woodpecker
  • Black-backed woodpecker
  • Red-naped sapsucker

Pacific Region

  • Northern Flicker
  • Downy woodpecker
  • Pileated woodpecker
  • Hairy woodpecker
  • Three-toed woodpecker
  • Black-backed woodpecker
  • Red-breaster sapsucker
  • Red-naped sapsucker
  • Yellow-bellied sapsucker (far north only)

Northern Territories

  • Northern Flicker
  • Downy woodpecker
  • Hairy woodpecker
  • Three-toed woodpecker
  • Black-backed woodpecker
  • Yellow-bellied sapsucker

Woodpecker Conservation Status

Although some woodpecker popluations are decreasing, most woodpeckers are doing fine conservation-wise. A few species are considered ‘Near Threatened’, which is only two short steps from ‘Endangered’ on the IUCN conservation scale. These troubled species are:

  • The Red-cockaded Woodpecker Leuconotopicus borealis, a native of the southeastern USA, considered already Endangered under the Endangered Species Act.
  • The Red-headed Woopecker Melanerpes erythrocephalus, once common in southern Canada and the east-central United States.

See Also

How to Attract Woodpeckers to Your Yard

Stopping Woodpecker Damage

Woodpecker References

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