Establish a Nest Box Trail for Bluebirds
Establishing a trail of nest boxes for Eastern Bluebirds is a worthy and very rewarding experience. A nest box trail for bluebirds does not need to have a walking path or designation for foot traffic. It is simply a series of nest boxes that provides a safe place for cavity-nesting bluebirds to lay eggs and raise their young. In fact, cavity-nesters, and bluebirds in particular, have become dependent on humans to provide boxes for nesting due to destruction of their natural habitat. As more land is cleared and developed a decrease in natural habitat makes it more difficult for bluebirds to find naturally occurring cavities such as hollow trees, snags and holes in wooden fence posts. Creating a nest box trail and monitoring the conditions helps ensure the survival of bluebirds in the United States.
Requirements for Bluebird Nest Box
- Made of unpainted wood, such as cedar
- 4" x 4" square floor dimensions
- 1.5" round opening for entrance
- Flat roof to provide a place for the birds to land
- NO perches should be on a box for bluebirds (perches enable other unwanted species to access the birdhouse, possibly killing the bluebirds)
- A hinged opening for cleaning box when birds have fledged
- Grooves on INSIDE wall of opening entrance to allow fledglings to access opening
- Mounted on a steel pole about 5-6 ' high to deter predators, or wood post if your ground won't support a metal pole
If you have been successful at hosting a bluebird family in a nest box already, and you have a few acres of land available for use, it is possible to put up several boxes and establish a trail of nest boxes. Usually the male bluebirds establish territories made up of one or more acres, so a large plot of land is best. If the nest boxes are any closer than about 100 yards apart they may not be used, or could cause territorial rivalries. However, not everyone owns large amounts of property, so consider whether your area has a walking trail or green belt with open woodlands, fence-rows, golf courses, cemeteries or parks. Your neighborhood association or school may be willing to let you establish a trail of nest boxes on common property in your neighborhood. In turn, your trail could generate knowledge and friendship from other birders, or even spark an interest in nature and birds for other neighbors. The more interest people have in our natural world, the more they practice conservation to preserve it. Another idea is to involve several cooperative neighbors if you are in a suburban area, by placing the trail in side or connecting yards that are accessible, if you have their permission, of course. As long as the nest boxes on your trail are being monitored regularly, and the boxes are made specifically for bluebirds with the correct requirements, your bluebird trail should be successful.
Location, location, location
To begin planning your trail, decide how much property you have access to and the best location for the boxes. My bluebird trail currently has four nest boxes. I have access to about seven acres with three nest boxes on my property and one nest box on my neighbors' five acre property. This allows the bluebirds plenty of open territory, but the boxes are close enough to monitor easily. On the other hand, do not place your nest boxes too close to heavy brush and trees, as this attracts wrens, who will compete with the bluebirds for the box. By placing the boxes at least 100 feet from thick shrubs, the wrens will be less likely to take over the nest box trail you are trying to establish for bluebirds, who need help with manmade habitats to give them safe places to nest.
Weather and Climate Considerations
Once you have chosen the location of the individual boxes on your bluebird trail, you will need to consider how to orient the entrance opening that the birds will use to enter the box. The birds prefer a sunny opening, but more importantly, try to protect the entrance opening from the hot afternoon sun and try to protect it from prevailing winds, especially if you live in a cooler climate. Bluebirds begin nesting in mid-February in Texas, but nights and mornings can still occasionally be cold. If conditions are good, bluebirds will raise two to three broods per year, with the last in July. Mid-summer temperatures inside a nest box can get dangerously hot, especially in Texas, so depending on your latitude, altitude and sun exposure, it would be helpful to face the opening away from the sun, plan for afternoon summer shade if possible, or insulate the nest box. It is also helpful to locate the box so there is a landing perch such as a low tree limb or fence post within about 60 feet, so when the fledglings leave the nest they have a place within reach of their young wings to land.
When nest boxes are placed in open areas bluebirds have a better chance of protecting their young from predators. Bluebirds are better able to see raccoons, skunks, cats, hawks and snakes when they are defending an environment with good visibility and fields are cut short around the boxes. Invasive birds, such as European starlings and house sparrows, are notorious for killing bluebird hatchlings and parents, solely to occupy the nest box, even though they do not need a nest box in order to reproduce. If a male house sparrow tries to dominate and claim a nest box on your bluebird trail, every effort must be made to prevent the house sparrow from nesting in the box. Cowbirds can lay their eggs in a bluebird nest in hopes of the female bluebird raising it as her own. If a large white cowbird egg is found in a nest on your trail, it should be removed and taken away from the trail.
Monitoring Your Trail
Trails of nest boxes need monitoring to ensure they are the most advantageous for the bluebirds. These monitoring walks are when you will reap the rewards of setting up your nest box trail. It is important to label or name each individual box if you want to report your data, so when you gather your information, it will be clear which box each set of data is for. Once you learn the dates to expect nest building, egg laying, hatching, brooding, fledging and nesting again, you will want to check your boxes to note the results and to prevent or correct any potential problems. You may submit your data to the Cornell Lab of Ornithology Nestwatch program at http://nestwatch.org/. This site will guide you as to what to look for when monitoring your nest boxes, such as number of young hatched, presence of the adults, presence of predators, cowbird activity, dates, conditions and locations. As you check the boxes, you should always be aware of insects such as fire ants and wasps, and if they are near the nest boxes remove them. Wasps build their nests inside nest boxes, attaching the nest to the ceiling, so always check the ceiling inside the boxes when you monitor them.
For More Information:
If you want to learn more about bluebirds and how to provide a habitat such as a nest box trail, search online to see if your area or state has a local bluebird society, such as the Texas Bluebird Society.
Useful information can be also be found at the North American Bluebird Society or the National Audubon Society. Links are found at end of article.
As you can see, there are many specific characteristics that are important for a well-planned bluebird trail. Through trial and error, it has been discovered that by following these requirements for establishing your nest boxes, your bluebird trail will be more successful and you will be rewarded with the presence of many beautiful bluebirds.
Links with more information:
- National Audubon Society | Audubon
- North American Bluebird Society
- Texas Bluebird Society - to promote the conservation of bluebirds
Texas Bluebird Society is an all-volunteer grassroots organization helping bluebirds and other cavity-nesting birds through increasing nesting sites while sustaining and increasing their food supply (insects; berries of native plants)