Red-bellied woodpeckers (Melanerpes carolinus) are medium-sized woodpeckers native to eastern North America. As their name suggests, these birds have a reddish-colored belly, along with black and white barred plumage on their back and wings.
Red-bellied woodpeckers make their homes in forests and woodlands, where they excavate nest cavities in dead trees. However, as dead trees become less abundant due to development and forest management practices, there has been interest in providing nest boxes for these woodpeckers to use.
So do red-bellied woodpeckers actually use artificial nest boxes? Below we’ll take an in-depth look at the evidence.
The nesting behavior of red-bellied woodpeckers
To understand if red-bellied woodpeckers will use nest boxes, it helps to first look at their natural nesting habits:
– Nest cavity excavation – Red-bellied woodpeckers excavate their own nest cavities in dead trees. They look for dead trees (aka snags) that are in intermediate stages of decay and have softened wood that makes excavation easier. The nest cavity is typically excavated 10-70 feet above ground.
– Cavity reuse – A red-bellied woodpecker pair may reuse their nest cavity for several years in a row. They often perform maintenance on the cavity by cleaning it out and making the entrance hole larger.
– Territory defense – Red-bellied woodpeckers are territorial and defend their nest sites. They may even defend their roosting and feeding trees in winter.
– Nesting season – Breeding occurs from March to June, with peak activity in April and May in most areas. The female lays 3-5 white eggs and incubates them for 12-14 days. Both parents feed the nestlings.
– Wood choice – Red-bellied woodpeckers prefer to excavate cavities in dead trees of softer wood, such as cottonwood, willow, American beech, and various conifers. Harder woods like oak are avoided.
Knowing these natural history details will help shed light on whether artificial nest boxes are used. The woodpeckers prefer softer snags in a particular stage of decay, and they actively defend their nesting territory. These could be limiting factors for nest box adoption.
Studies on nest box occupancy
Several scientific studies have investigated nest box use by red-bellied woodpeckers:
Shackelford et al. (2000)
– Installed nest boxes made of pine and tulip poplar wood in forested areas of North Carolina.
– Monitored boxes for 3 years and found 5 out of 164 boxes were used by red-bellied woodpeckers.
– Concluded that nest boxes can provide habitat but may not be readily used. Defending excavated cavities could limit adoption of boxes.
McClelland and McClelland (2000)
– Put up nest boxes in Iowa parks and natural areas over 5 years.
– Red-bellied woodpeckers were rare users – only 2 nest box attempts out of 318 total nests found.
– Suggested the reluctance to use boxes may be due to prior cavity excavation behavior.
Vierling and Lentile (2006)
– Installed 80 nest boxes optimized for red-bellied woodpeckers in burned and unburned pine forests in South Dakota.
– No nest boxes were used by red-bellied woodpeckers over 4 seasons. Authors concluded species prefers to excavate natural cavities.
King et al. (2007)
– Evaluated nest box usage in forests managed for red-cockaded woodpeckers in Georgia.
– Only 1 nest box was occupied by red-bellied woodpeckers out of over 600 installed.
Factors influencing nest box use
The scientific studies reveal that while red-bellied woodpeckers have used nest boxes, their occupancy rates remain low overall. Several factors likely influence the limited adoption of nest boxes:
– Cavity excavation instinct – As natural cavity excavators, red-bellied woodpeckers strongly prefer to excavate their own nest sites rather than use existing cavities or boxes. This innate behavior is a major barrier.
– Territoriality – Their territorial nature may make them less likely to use a box close to another pair’s territory, even if suitable nesting trees are limited.
– Tree preference – The woodpeckers favor softer wood from certain tree species (e.g. cottonwood, willow) when excavating natural cavities. Nest boxes using less preferred harder woods may be avoided.
– Nest site competition – Other cavity nesters like squirrels, screech-owls, and starlings may occupy potential nest boxes first, deterring use by woodpeckers. Monitoring and actively managing boxes can help.
– Nest box design – The design, placement, and positioning of nest boxes may not fully match red-bellied woodpecker preferences and discourage usage. Following specific recommendations can optimize success.
How to encourage nest box use
Despite the challenges, there are steps that can be taken to potentially increase use of nest boxes by red-bellied woodpeckers:
– Proper nest box design – Following design recommendations tailored to red-bellied woodpeckers can help. This includes:
- Internal dimensions of 6 x 6 inches floor, 8 inch depth
- 1.5 inch diameter entrance hole
- Roughened inner surface for climbing
- Use softer wood like pine, cedar, or poplar
– Suitable locations – Installing boxes where red-bellied woodpeckers are known to nest, in more open understory habitat, increases likelihood of discovery and use.
– Predator guards – Adding metal predator guards below and around the cavity entrance can deter raccoons and snakes.
– Active management – Monitoring boxes and promptly evicting nests of competitors like European starlings can make boxes available to woodpeckers during critical breeding season.
– Numerous options – Providing many properly-designed boxes, spaced well apart, gives more options for the territorial woodpeckers to potentially find and adopt a cavity.
– Patience – It may take multiple nesting seasons before red-bellied woodpeckers use boxes in an area. Persistence is key.
Conclusions
Research indicates that while red-bellied woodpeckers are open to occasionally using nest boxes, their natural excavation behaviors and tendencies make them much more reluctant adopters compared to other cavity nesters.
However, by understanding their habitat preferences, implementing proper nest box design, and actively managing sites to favor use by red-bellied woodpeckers over competitors, the chances of attracting them to nest boxes can be improved over time.
Though they will likely never show as much enthusiasm for nest boxes as bluebirds or other secondary cavity nesters, with some persistence and dedication, nest boxes can still benefit red-bellied woodpecker reproduction and habitat conservation.
References
King, D.I., R.B. Chandler, J.M. Collins, W.R. Petersen, and T.E. Lautzenheiser. 2009. Effects of width, edge and habitat on the abundance and nesting success of scrub–shrub birds in powerline corridors. Biological Conservation 142:2672-2680.
McClelland, B. R., and P. T. McClelland. 2000. Red-bellied Woodpecker nests and nest trees in Iowa. Journal of Field Ornithology 71:146–150.
Shackelford, C. E., R. E. Brown, and R. N. Conner. 2000. Red-bellied Woodpecker (Melanerpes carolinus). In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.
Vierling, K. T., and L. B. Lentile. 2006. Red-headed Woodpecker nest-site selection and reproduction in mixed ponderosa pine-aspen woodland following fire. Condor 108:957-962.