One initial question new bluebird landlords have is which direction should their birdhouse or nest box face. It is best to point your bluebird house’s entry hole in the opposite direction of prevailing winds, usually southeast. However, prevailing winds differ based on your region. Scholarly evidence also suggests birds have no preference and may excavate a hole in other directions due to sun, shade or acoustics.
When it comes to bluebird house direction and bird preference, there has been conflicting observations about the preferences of primary cavity excavating birds (original tree hole creator such as a woodpecker).
Some studies suggest there is a preference depending on a bird’s need for sun or shade or to better hear. Other studies, however, suggest excavation is random. One example where this was found was in a 2004 study for chickadees. Not only did researchers find that their preference was random. But when they also presented black-capped chickadees with nest boxes oriented in 90° intervals, they observed random choice as well (Mennill & Ratcliff, 2004).
What this means in terms of your nest box setup is that the direction of the nest box’s entry hole is very unlikely to influence whether birds will nest there or not. And the outcome of these studies all really suggest that there is no primal, instinctive direction birds uniformly choose for their cavity nest entry holes.
Instead, your goal in orienting your bluebird box is to protect the birds and provide comfort and shelter. You want to be sure that the orientation of your nest box will minimize water penetration, wind, etc. This is why it’s suggested to have your nest boxes face away from prevailing winds. This typically means orienting your box in a southeasterly direction. However, prevailing winds can depend on your area.
In fact, prevailing winds can be very different depending on location. For instance, in the United Kingdom, average wind direction varies greatly throughout. And there can also be differences throughout each season (Lapworth & McGregor, 2008).
Therefore, when positioning your nest box’s entry hole for bluebirds or other cavity nesters, it is recommended you research the direction of prevailing winds in your area.
Determining the prevailing winds in your area for better nest box orientation
Prevailing winds are the winds blowing in the most common direction for your area (highest average wind direction). For the most part, these winds tend to be determined by geographical latitude, topography and bodies of water, but other aspects of your location and the time of year can influence what direction your prevailing winds blow.
One way to determine the wind direction in your area is to simply observe. A weathervane or a DIY weathervane can tell you a lot. Watching the weather report in the morning can also tell you a lot.
Of course, you might not be wanting to spend all that time charting wind direction daily. Especially if it’s nesting season and you just want to put your birdhouse up.
Instead, you can look up the general wind direction of your area. That’s as easy as a Google search. When Googling, look for a consensus and clear information. You may also find resources in your results.
A really helpful resource to look for when googling is a regional wind rose. A wind rose is a circular graphic with 16 petals that chart wind speed and direction. Based on the mapped illustration, you’ll be able to easily determine prevailing winds (the dominant direction of wind) in your area.
Aside from googling, one really helpful resource comes from Iowa State University. Within their website are tools to access historic wind information gathered mainly from airport databases.
Here is how to use the resource:
1.Visit https://mesonet.agron.iastate.edu/sites/locate.php
2.Select your state or area using the “select your network dropdown.” Choose the state. Then hit the “Switch Network” button.
3.Next, drill down on your location by using the “Select By Station” drop down. And then click the “Select Station” button. You can also do this by selecting the station on the map. Note: Not all stations will have wind rose information. Switch stations or networks if that’s the case.
4.After you’ve made your selections, you’ll be presented with stats and options for that station. Some stations will not have a lot of information available, but others will. From that display, look for the option that says “Wind Rose” and select that.
5.If wind data is available, you’ll be presented with a Wind Rose to help you visually determine prevailing winds. This station also provides monthly data, which is very helpful when considering the breeding season of bluebirds.
6.Analyze your wind rose results. Essentially, you’re looking for graphical depiction showing the most prevalent wind direction. In the example above, it would appear that winds prevail mainly from the west.
7.Consider monthly data if it is presented. In this case, there are monthly wind roses available. This is important when thinking about the direction your bluebird house should face because you want to make sure it’s oriented away from prevailing winds during the bluebird breeding season (March – August, with variance depending on location).
8.Determine the best direction for your nest box based on the wind information you’ve researched. When considering any monthly insights, we’re not at all recommending you continually move your nest box, or reposition the direction it’s facing. Instead, determine the most prevalent average direction of wind during the breeding season for your location, and position your nest box entry hole in the opposite direction.
Bluebird house placement considerations
Aside from orientation, there are other very important factors to consider when setting up your bluebird house.
A few important bluebird house placement tips include:
- Properly mounting the bluebird nest box on a metal pole.
- Do not mount a bluebird nest box to a tree or wooden fence post.
- Set your pole system up in open space with trees nearby but not too close.
- Provide water – running water is even better.
- Stock bluebird feeders with mealworm and add pulverized eggshells to supplement calcium.
- Ensure proper protection from predators by installing a stovepipe style baffle onto the pole.
From our experience, bluebirds tend to prefer nest boxes in open space, at least 50-75 feet from a tree line. They still need trees and shrubs around to provide protection, cover and places to perch.
Additionally, providing a regularly cleaned and filled water baths with solar fountains not only attracted bluebirds, but also other native cavity nesting birds.
Do not put up a bluebird house or try to attract bluebirds to a nest box if you have seen several house sparrows in your area. Bluebirds will be less attracted to these sites, but you also put them at risk of death if they do nest in an area full of house sparrows.
If you are wanting to attract bluebirds and other native cavity nesting birds, but also have house sparrows in your area, the first step will be trapping and eliminating them.
House sparrows are not protected in the United States. You will, however, need to check with your local and state laws as these may be different.
When trapping house sparrows, it is also very important you are able to clearly identify what is and what is not a house sparrow. This can be especially tricky for female house sparrows versus other birds like female house finches and pine siskins to name a few.
Do not let cats roam freely outdoors when you are placing bluebird houses in your yards. Outdoor cats are among the many predators of wild birds, and bird houses can put mother birds and young in a very vulnerable position.
For more information about bluebird predators, we have a really detailed article about common bluebird predators and how to protect against them.
Quick summary for determining the direction to put a bluebird house:
- Birds do not have an instinctive preference as to which direction the nest hole faces; however, they may still choose a nest site based on amount of sun, shade, wind, acoustics, etc.
- When positioning a bluebird house, it’s best to have it face in the opposite direction of prevailing winds in your area.
- Prevailing winds are not always westerly. In fact, they vary widely from location to location and from season to season. Topography, latitude, season, and proximity to large bodes of water are among some of the factors influencing the direction of prevailing winds.
- Perform quick research via Google or a climate resource to determine the average wind direction in your area during the breeding season.
- When putting up a bluebird house, ensure it is properly mounted to a metal pole and guarded from predators.
References
Clendenin, W. W. (1893). THE RELATION OF THE PREVAILING WINDS TO THE PHYSICAL FEATURES OF MISSOURI. American Meteorological Journal. A Monthly Review of Meteorology and Allied Branches of Study (1884-1896), 10(2), 65.
Lapworth, A., & McGregor, J. (2008). Seasonal variation of the prevailing wind direction in Britain. Weather, 63(12), 365-368.
Mennill, D. J., & Ratcliffe, L. M. (2004). Nest cavity orientation in black‐capped chickadees Poecile atricapillus: do the acoustic properties of cavities influence sound reception in the nest and extra‐pair matings?. Journal of Avian Biology, 35(6), 477-482.
Massey, R., & Guinan, P. (n.d.). Missouri Agricultural Weather Wind Information and Resources. AgEBB. http://agebb.missouri.edu/weather/windroses/.
Trees-Energy-Conservation. (2019, September 11). Understanding and determining prevailing winds. Trees for Energy Conservation. https://trees-energy-conservation.extension.org/understanding-and-determining-prevailing-winds/#:~:text=standing-and-determining-prevailing-winds/
