Finding the Right Birdhouse
Expanding on last week’s article about building birdhouses for cavity nesting birds, this week we will be providing some basic information about selecting a nest box (birdhouse) for the cavity nesting birds you wish to attract to your yard and benefit during the upcoming nesting season. There are a lot of birdhouses available on the market, at department stores, hardware stores, online, and other outlets, but many of these products don’t meet some of the basic requirements of a good birdhouse. That’s where this article can help you look a little deeper what makes a standard birdhouse.
Essentially, what we want to do is help you make informed decisions when you select the best nest box for the birds you would like to have nest in your yard or property. And to introduce you to how to position them in appropriate habitat, where they are safe from predators, so you can enjoy observing the nesting action this spring and summer. It’s not an exaggeration to say that providing nest boxes for native cavity nesting birds is more important than ever, so anything you can do to help is honestly important!
On to selecting a birdhouse: You will find that many birdhouses are made to be attractive to people, but they really don’t serve the basic interests of a well-made, safe birdhouse (nest box). Some are even counter-beneficial to birds in need of a cavity nesting site. An appropriate birdhouse has some very important features that even a natural cavity or a woodpecker-created cavity may not provide. Hence, you can improve on nature by providing the right birdhouses for our native cavity nesting birds.
Before getting into a list of features for a good birdhouse, let’s take a look at a best-case example of one: The “Cedar Bluebird House” is one of the best examples of a nest box that we have seen. It has all the details to make it a preferred product, including a unique clear plastic viewing window inside the side panel that opens and allows you to easily monitor nesting birds’ activities periodically. This premier nest box is very affordable and available from BestNest at Nature’s Way Cedar Bluebird House with Viewing Window at BestNest.com However, this nest box is only a good choice for birds that use a 1½ inch entrance hole (but the hole size can be altered with a small entry adaptation).
What cavity nesting birds would you like attract to your property? Below we provide a simple guide to consider before buying a birdhouse or nest box. In fact, if you have existing birdhouses in your yard that don’t have these qualities, you may want to consider replacing them with birdhouses that provide these simple features.
The Features of a Good Birdhouse:
1) Wood & Screws – More specifically, buy a birdhouse that is built with unpainted, unvarnished, untreated wood – just good old wood. The wood should be ¾ inches wide to help maintain a more uniform temperature (boards listed as 1 inch are actually ¾ inches wide). While checking the wood, also consider that screws are better construction materials than nails.
2) Hinged Panel – One of the things missing from many nest boxes is a way to access the inside of the nest box – a feature that is imperative for monitoring, maintaining, and cleaning any nest box. Access is usually provided via a hinged side panel of the nest box, but also check for a sturdy closing mechanism so the opening side can’t open unexpectedly.
3) Ventilation – A small ventilation slot near the top of nest box, preferably a small slot at the top of the 2 side walls is a good bet, but the equivalent of 2 holes drilled at the top of each side wall is good too (4 holes total, 5/8 inch diameter).
4) Drainage – To ensure no water pools inside there should be about 5 small holes, about 1/2 inch in diameter, 1 in each corner and 1 in the center.
5) Sloped Roof – The roof should slant forward and overhang the birdhouse walls by 2 to 4 inches in front and 2 inches on sides to keep water from seeping in, and to deter predators to a degree.
6) Climbing Ladder – Inside the box, below the entrance hole, the wood should be scored to permit nestlings to get a foot hold to climb to the entrance when they are ready to fledge.
7) Entrance Hole! – One of the most important considerations for any birdhouse is the size of the Entrance Hole. The idea is to have the hole diameter as small as possible, so larger birds cannot take over a nest box meant to attract smaller birds. That is also important to keep non-native birds like House Sparrows and European Starlings from monopolizing birdhouses meant for chickadees, wrens, and others.
Each species has a preferred entrance hole size; for example, a 1 inch diameter hole for House Wrens and Bewick’s Wrens, a 1 1/8 inch diameter is best for chickadees, and a 1 1/2 inch diameter entrance hole is best for Western Bluebirds and Eastern Bluebirds.
In the same way, the size of the nest box for individual species varies, as do the habitat requirements, the positioning of the nest box in your yard, the elevation that best, and more nest box dynamics. Therefore, it’s best we refer you to NestWatch for the rest of the information about specific species. You can get all the information you need on the species you are most interested in, or in all cavity nesting species in general at NestWatch, along with info about some shelf-nesting species like robins and phoebes. The following link is for House Wrens, but you can easily change the name to access info about any cavity nesting birds; see House Wren – NestWatch
There are 2 other important requirements for each birdhouse: Predator Proofing and Competition Monitoring. All nest boxes need predator proofing, either a cone-shaped metal baffle or a long piece of stove pipe metal that will stop raccoons, squirrels, snakes, cats, and other potential predators from reaching any birdhouse. Don’t let your nest box become a snack box!
As for Competition, non-native House Sparrows and European Starlings often compete with native birds for cavity nesting sites, which reduces reproduction among natives. Please don’t permit any individuals of these 2 species to use any of your birdhouses. If they begin building a nest – remove the material – time after time if necessary. Block the entrance for a couple days if necessary. Keeping these 2 species from using birdhouses is the most important part of monitoring each nest box: It’s not a pleasant part of birding, but on a conservation level, it’s necessary when providing birdhouses meant for native cavity nesting birds.
Especially useful for anyone interested in providing birdhouses for any native cavity nesting species is the Cornell Lab’s NestWatch website at All About Birdhouses – NestWatch
On more thing, when you have your birdhouse installed and ready for a pair of birds to claim it for the nesting season, you may need to add some extra patience to your birding repertoire, because it may take some time for birds to find and use your new birdhouse. In some cases it may take a year before a new pair moves in, but hang in there, a pair may lay claim within a week or 2 if you’re lucky – you will be rewarded in time.
In this second February article about nest boxes, we have limited our references to smaller songbirds or songbird-sized cavity nesters. In a future Backyard Birding article we will also emphasize larger cavity nesting birds and how to provide a Big Nest Box for cavity nesting owls, kestrels, and ducks – stay tuned, and good luck with all your birding activities.
Share your backyard birding experiences and photographs with The Birding Wire at editorstbw2@gmail.com
