Woodpeckers are fascinating birds that peck away at trees to create cavity nests. These nests are used for roosting and raising young. A question that often comes up is whether woodpeckers reuse the same nesting cavities year after year or if they abandon them and create new ones each season. There are a few factors that influence whether a woodpecker will return to an old nest or excavate a new one.
Why Do Woodpeckers Excavate Cavity Nests?
Woodpeckers create cavity nests by chiseling out holes in trees. They use their strong beaks and long, barbed tongues to chip away at the wood. Cavity nests offer woodpeckers protection from predators and shelter from the elements.
Excavating a nest takes a lot of time and effort. It may take a woodpecker weeks or even months to complete a nest cavity. The process is energetically expensive. So once a nest is constructed, woodpeckers would benefit from reusing it rather than excavating a new one each year.
Do All Woodpecker Species Reuse Nests?
Whether a woodpecker excavates a new nest or reuses an old one depends partly on the species. Here are some general trends:
- Most woodpecker species reuse nest cavities. These include downy woodpeckers, hairy woodpeckers, red-bellied woodpeckers, and red-headed woodpeckers.
- Larger woodpecker species like pileated woodpeckers typically excavate a new nest each year.
- Some migratory woodpecker species reuse nests, while others excavate new cavities annually.
- Cavity nesters like woodpeckers face competition for nest sites from other bird species. This may limit reuse of old cavities.
In general, smaller woodpecker species are more likely to reuse nesting cavities compared to larger woodpeckers. However, even within a species there can be variability depending on factors like cavity competition.
Downy Woodpeckers
Downy woodpeckers are common birds across much of North America. They are small woodpeckers that only grow to about 6-7 inches in length.
Downy woodpeckers are known to reuse old nesting cavities. However, they may excavate a new one if no suitable old nests are available. One study in Colorado found downy woodpeckers reused nest cavities in 87% of observed nesting attempts.
Reuse of old nests allows downy woodpeckers to save energy. They invest a lot of time and effort excavating nest cavities, so reuse is beneficial. It also lets them start breeding earlier in the season.
Hairy Woodpeckers
Hairy woodpeckers look very similar to downies but are larger in size. These woodpeckers are also cavity nesters but prefer to nest in dead trees or dead parts of live trees.
Research shows hairy woodpeckers strongly prefer to reuse old nesting cavities. One study in California found hairy woodpeckers reused nest sites in 98% of observed nesting attempts.
Hairy woodpeckers may reuse a nest for many years. The long-term reuse saves them energy since excavating a nest takes so much work. It also lets them breed earlier by occupying old nesting sites.
Pileated Woodpeckers
In contrast to smaller woodpeckers, pileated woodpeckers do not typically reuse old nesting cavities. Pileated woodpeckers are very large birds, growing up to 19 inches long. They excavate large rectangular holes in trees for nesting.
One reason pileated woodpeckers usually make a new nest each year is because of their size. They require a larger nest cavity that stays intact over the winter. The big holes they excavate are more prone to deterioration than smaller cavities.
Pileated woodpeckers may also abandon a nest if it gets infested with parasites like bird fleas. Excavating a new cavity helps them avoid parasite buildup.
While not common, there are occasional reports of pileated woodpeckers reusing old nesting cavities. This shows some flexibility depending on circumstances.
Why Do Woodpeckers Reuse Nests?
For woodpeckers that do reuse nesting cavities, there are several major benefits:
Saves Energy
Excavating a woodpecker nest takes an enormous amount of effort and calories. It requires repeated hammering and chiseling for weeks to months depending on the size of the cavity. Reusing an old nest saves woodpeckers this huge energy expenditure.
Get a Head Start on Breeding
Woodpeckers that reuse a nest are able to start breeding earlier in the spring. They don’t have to take weeks to excavate a nest first. Earlier breeding gives the young more time to mature and prepare for winter.
Offers Protection
Old woodpecker cavities have already survived being exposed to the elements for a full year. This proves they can withstand wind, rain, and other hazards. Unproven new nests may be more at risk of failing before eggs can hatch.
Familiar Location
By reusing the same nest, woodpeckers return to a familiar cavity and territory. This gives them intimate knowledge of good feeding areas near the nest to provision young.
Why Do Woodpeckers Excavate New Nests?
On the other hand, there are some reasons why a woodpecker may abandon an old nest and dig a new cavity instead:
Deterioration of Old Cavity
If an old nesting cavity becomes too deteriorated over the winter, the woodpecker will be forced to excavate a new one. This is most common with larger nest cavities.
Parasite Buildup
Reusing a cavity increases exposure to parasites like fleas, mites, and nest flies. Excavating a new cavity can allow the woodpecker to escape these pests.
Competition for Cavity
There is a lot of competition for cavity nest sites from other bird species. If another animal like a squirrel or bird occupies their old nest, woodpeckers have no choice but to dig a new one.
Changing Nest Sites
Some migratory woodpecker species appear to change nest locations each year either by choice or necessity. Their previous tree may have been destroyed in the previous year.
Disturbance
Human disturbance can cause woodpeckers to abandon a nesting cavity if the area becomes unsafe. Loud noise, tree removal, or other disruptions may force them to nest elsewhere.
How Long Do Woodpeckers Use a Nest?
Most woodpecker nests are used for just one breeding season before being abandoned. However, woodpeckers may reuse a nest for several years in a row. Here are some statistics on woodpecker nest reuse:
- Downy woodpeckers may reuse a nest up to 5 years in a row.
- Hairy woodpeckers have been documented reusing a nest for 11 consecutive years.
- Acorn woodpeckers may reuse a nest cavity for up to 15 years.
- Red-cockaded woodpeckers routinely reuse nests for 10+ years.
The length of reuse depends on how long the cavity remains intact. Woodpecker nests deteriorate over time from factors like water damage, enlargement of the hole, and disintegration of the wood. Larger nest cavities tend to degrade faster than smaller ones.
Parasites and competitors will also eventually force woodpeckers to abandon a nest if used too many seasons in a row.
Do Woodpeckers Use Old Cavities Excavated by Other Species?
In addition to reusing old nests, some woodpeckers will occupy abandoned cavities originally made by other woodpecker species. Using old nests saves them the work of excavating their own.
Downy woodpeckers, for example, often reuse holes created by larger woodpeckers like the northern flicker. This gives them a nesting site they may not be able to excavate on their own.
Woodpeckers may compete intensely for access to these ready-made nesting sites. The cavities offer protection with minimal effort for the occupant.
Do Other Animals Use Old Woodpecker Nests?
Woodpecker cavities are also highly sought after real estate for many other animal species. Here are some animals that may occupy an old woodpecker nest:
Birds
- Chickadees
- Nuthatches
- Bluebirds
- Titmouse
- Owls
- Ducks
- Swallows
- Sparrows
Mammals
- Squirrels
- Bats
- Chipmunks
- Raccoons
- Martens
Insects
- Bees
- Wasps
- Ants
Reusing an old woodpecker nest saves these species the effort of building their own nest in a tree. It offers ready-made housing in a protected cavity.
Strong competition for prime nesting sites is likely one reason woodpeckers excavate a new cavity each year. It ensures they get a nest not already occupied by other animals.
How to Attract Woodpeckers to a Nest Box
Another way to observe woodpecker nesting behavior is to install wooden nest boxes suitable for cavity nesting birds. Here are some tips to attract woodpeckers:
- Use untreated, unpainted wood at least 3/4 inches thick.
- Make sure the entrance hole is appropriate for the desired woodpecker species.
- Add some wood shavings or sawdust as bedding material.
- Mount the box at least 10-30 feet high on a tree trunk.
- Face the entrance away from prevailing winds and rain.
- Clean out old nesting material in fall to prepare for spring.
With the right nest box in a suitable habitat, you may be able to attract woodpeckers to reuse it year after year. Just be sure to mount it securely so other animals don’t dislodge it!
Conclusion
Most woodpeckers prefer to reuse old nesting cavities when possible. This saves them the huge effort required to excavate a new cavity each breeding season. However, some factors like cavity competition, parasites, and disturbance may prevent reuse and force woodpeckers to continually excavate new nests.
Cavity reuse varies depending on the woodpecker species. Smaller woodpeckers are more likely to reuse old nests compared to larger woodpeckers like the pileated. But even within a species, individual birds may excavate a new cavity or reuse an old one depending on circumstances.
Watching a woodpecker nest offers great insight into their behavior. You may be surprised how many years your resident woodpeckers reuse the same tree! Installing a nest box is another way to observe nest site fidelity.