Wren birds are small, active songbirds that are common across much of North America. They are cavity nesters, meaning they build their nests and lay their eggs inside enclosed spaces like birdhouses. Wrens are popular birds for birdwatchers to attract to their yards using manmade nest boxes. However, one question that often comes up is how close together wren houses can or should be placed. There are a few factors to consider when deciding the appropriate spacing between wren birdhouses.
Wren Territory Size
Wrens are territorial songbirds, meaning they claim an area around their nest as their own and defend it from intrusions by other wrens. A wren’s territory may range from 1/4 acre up to 1 acre in size. This means that in order to prevent conflict over territory, wren houses should be spaced widely enough apart that each house falls within the boundaries of a different wren pair’s territory. As a general rule, wren houses should be spaced at least 100-200 feet apart to provide adequate space.
Predation Risk
When bird houses are clustered too closely together, it can draw the attention of predators and increase the risk of nests being raided. Predators like cats, racoons, and snakes may find it convenient to prowl an area with many potential bird nests concentrated together. Spreading wren houses out over a broader area helps minimize this risk. Spacing houses at least 100 feet apart forces predators to hunt over a wider territory to find nests rather than just patrolling a small area of dense housing.
Competition for Nest Sites
Wrens are known to be aggressive about claiming prime nesting real estate. A single pair may claim multiple bird houses within their territory, then fill the extra houses with sticks to prevent other birds from using them. This tendency is exaggerated when houses are placed too close together. Spreading houses widely apart allows each space to be claimed by a separate wren pair and decreases competition between wrens over sites. The houses will more likely be used for actual nesting rather than blocked off territorially.
Reduced Reproductive Success
Research has shown that wrens nesting in close proximity to other pairs had lower rates of reproductive success. This may be due to increased disturbances from neighbors causing more frequent interruptions of incubating and nesting birds. The noises and activity of nearby wrens can stress nesting pairs and cause them to be less attentive parents. Nestlings also showed slower development when houses were within 50 feet of each other. For best results, follow the 100-200 spacing rule to give each pair enough privacy.
Ideal Placement of Wren Houses
When deciding where to mount wren houses in your yard, keep these tips in mind:
North or East Exposure
Face the entrance holes toward north or east directions to avoid hot afternoon sun. South or west facing openings may overheat the interior of the box and cause chicks to overheat. Eastern exposures provide the most protection from precipitation and weather.
5-10 Feet High
Mount houses 5-10 feet above ground on undisturbed posts or poles. This height protects nests from most predators while still being low enough for wrens to access easily. Make sure poles are sturdy enough that houses don’t swing in wind.
Away From Feeders
Do not place houses directly adjacent to bird feeders. The activity and noise will disturb nesting birds. Leave at least 20-30 feet between feeders and nest boxes.
Nearbrush Or Trees
Wrens prefer locations with dense vegetation nearby to provide cover. Place boxes within a few feet of brush piles, shrubs or tree branches. Ensure the entrance hole has a clear approach path.
Avoid Disturbances
Pick quiet spots away from walkways, compost piles, garden sheds, etc. Human disturbances can frighten wrens and cause nest abandonment. Give them privacy.
How Many Households Per Acre?
As a general rule of thumb, you can successfully provide nesting sites for 1-2 pairs of wrens per acre. Here are some recommendations based on property size:
| Property Size | Number of Houses |
| Less than 1 acre | 1-2 houses |
| 1-2 acres | 2-3 houses |
| 2-5 acres | 4-6 houses |
| 5-10 acres | 6-12 houses |
Space the houses evenly around your property at least 100-200 feet apart. Make sure each one falls within a different wren pair’s preferred territory area and has suitable cover nearby. Monitor occupancy each season and add or remove houses as needed. With some trial and error, you can fine tune the number of nesting sites to suit your local wren population. Just be sure not to overload your space with too many crowded houses.
How To Monitor Occupancy
To keep tabs on which wren houses in your yard are being used each season, you can:
Watch Behavior
Observe wrens early in the season as they establish territories and choose nest sites. Watch for activity around specific houses, such as wrens carrying sticks into openings or defending the space around a box. Site fidelity is common, so they may reuse a successful nest from the previous year.
Check Contents
During the nest building stage, you can open the house and peek inside to see if wrens are actively furnishing it with twigs. Once eggs are laid, avoid disturbances until chicks fledge. Monitor by looking in the entrance hole for signs of use.
Install Cameras
Mini spy or game cameras can be mounted inside or outside nest boxes to monitor activity without disturbing the birds. Just be sure to remove the cameras before winter.
Track Data
Keep notes on occupancy, nest success, and number of fledglings each season. This helps determine which houses are preferred by wrens and if spacing or placement needs adjustment.
Tips For Attracting Wrens
Here are some tips to make your yard as attractive as possible to prospective wren tenants:
Provide Cover
Wrens prefer habitats with plenty of dense bushes, brush piles, shrubs, and low tree branches that offer cover. Maintain these protected areas.
Offer Nest Materials
Supply natural wren nesting materials like fine twigs, grasses, mosses, and plant fibers. You can include some in houses or set piles nearby.
Install Birdbaths
Wrens need access to water for drinking and bathing. A shallow birdbath with sloped sides provides suitable wren habitat.
Reduce Pesticides
Limiting use of insecticides and other chemicals ensures a healthy supply of invertebrates that wrens feed on.
Put Up Feeders
Black oil sunflower seeds in hopper or tube feeders will attract wrens to your yard. Suet feeders are also recommended.
Common Problems And Solutions
Here are some frequent issues that come up with wren houses and how to address them:
Sparrows Or Mice Move In
Block the entrance hole with wire mesh early in the off season to prevent unwanted occupants from taking over unoccupied houses. The mesh will allow wrens through in spring.
Predators Attack Nest
Mount predator guards or baffles below houses to prevent access. Ensure poles are sufficiently tall and smooth to deter climbing.
Nest Abandonment
Frequent harassment, poor weather exposure or lack of cover likely caused the birds to leave. Adjust placement to a better protected spot before next season.
Starlings Or Bees Take Over
Enlarge the entrance hole of a problematic house to 1 1/4 inches. This allows wrens access but excludes starlings and bees. Rehang the modified house in a new spot.
Competitive Fighting
Wrens squabbling over houses probably indicates they are too close together. Try relocating some to create more separation between territories next year.
Conclusion
Properly spacing and monitoring wren birdhouses will help attract a population of these active, entertaining songbirds to nest in your yard. Ideally, space houses 100-200 feet apart within suitable wren habitat. Limit placement to 1-2 houses per acre with north or east facing entrances positioned 5-10 feet up on poles or posts. Track occupancy each season and modify locations as needed to meet the territorial and nesting requirements of your local wrens. With a well-designed setup, you can enjoy observing the nesting behaviors of these tiny cavities birds for many years to come. Let the wren house adventures begin!
