Cavity nesting birds have a difficult time finding a place to nest. In fact, there simply aren’t enough suitable cavities to meets the needs of the birds that need them. Throughout Georgia a wide assortment of birds nest in tree cavities including the eastern bluebird, Carolina wren, house wren, house sparrow, tree swallow, European starling, purple martin, barn owl, tree swallow, screech owl, great crested flycatcher, Prothonotary warbler, and wood duck. In an attempt to offset the shortage of natural cavities, for more than eleven decades folks have been building and erecting nesting boxes. Beyond a shadow of doubt more nest boxes have been built for bluebirds than any other species. They have been so successful they have played a large part in the recovery of this beautiful bird.
While the majority of bluebird nesting boxes look pretty much the same, some provide better nesting sites for the birds than others. Often the only thing that determines whether or not a box is better than another is its color.
Bluebird nesting boxes are painted in a rainbow of colors. In fact, I once saw a black bluebird nesting in a blue bluebird box. I would like to know how many red and black See Rock City have been erected across the south. Some folks paint nesting boxes in the colors of their alma mater or favorite football team. Others leave boxes unpainted. With this bewildering array of colors to choose from, you might be wondering what works the best. In truth, bluebirds don’t seem to show a preference for any color. However, studies have shown that year in and year out more bluebirds fledge from boxes painted certain colors over all others. Let’s take a look at what’s best for the birds and your pocketbook.
Most store-bought bluebird boxes are unpainted. Typically, they are made from finished pine boards. If you take such a box home and hang it out without doing anything to it, chances are it will rot in a season or two and end up lying on the ground. Consequently, if you want the box to last a lot longer, coat it with a good quality exterior paint or stain before you put it up. When you treat a box in this manner, it will last several years. With most bluebird boxes costing anywhere from $10-$25 or more, this is a significant savings.
However, boxes made from cypress or cedar should not be treated. These woods naturally resist decay. It is not unusual for a well-made cypress box to last up to 25 years.
Here in the South, it is best to paint boxes a light color. Any light color is suitable. Bluebirds don’t care if a box is white, gray, light pink or pale blue. However, whatever you do avoid using dark colors. The reason for this is simple, pastel colors absorb less heat than boxes coated in dark colors.
Here in the Peach State during the spring and summer (the bluebird’s nesting season), the thermometer often soars above 90°F. However, when air temperature reaches only 87°F, the temperature inside a nesting box painted a dark color can soar to 107°F or more. When eggs are exposed to such intense heat, developing bluebird embryos can be killed. Bluebird eggs seem to develop best when temperatures inside a box are no higher than 99°F.
When painting a box, I prefer using an oil-base exterior paint. You will find it will last longer than other exterior paints. I ALWAYS avoid lead-based paints since there is always the potential that birds and other wildlife can ingest paint chips containing lead.
It is always best to paint a box before it is erected. Use a medium-sized flat brush. Apply at least one coat of paint to all exterior surfaces. If the bare wood absorbs a lot of paint, apply a second coat. I would recommend that you apply 3 or more coats of paint to the back of the box. Since this surface will be in direct contact to a tree, post, or metal pole, as such it will be exposed to water much longer than the other surfaces of a box. The extra paint provides an added barrier to water.
Under no circumstances should you paint the interior of box or its entrance hole. In fact, I recommend that you avoid using spray paint since there is always a possibility that paint can be accidentally sprayed inside the box.
Isn’t it amazing how a little dab of the right color paint can be so important to such a gorgeous and popular bird?
Saw our first hummingbird today, Saturday, March 30 in Covington. This was late for us. The earliest we had one was March 1 several years ago. Hope all is well with you. David
Sent from my iPhone
Hummers were late at our house too. Oddly, for about three weeks beginning in the middle of May were entertained 14+ hummers daily. These birds should not be acting this way at that time of the year. I suspect the drought we are experiencing around here has something to do with it.
Thank you for this very important article. My Bluebirds did not enter their boxes until they were painted a light pastel color. I use white or pastel green when I want to hide the box in the woods or brush.
Why don’t you paint the entrance hole of the bluebird house? Also if you paint with added artwork do you apply a clear protective coating of paint and what kind would you use? Thank you
The reasons for not painting the interior of boxes and entrance holes stems from the use of toxic paints decades ago. While many of these paints are no longer marketed, many experts still don’t recommend that they be painted. The reason for this is, as far as I know, no research has been done on the potential threats posed by newer paint formulas. That being the case, if potentially toxic paint flakes fell inside a box, they could be consumed by young birds. Additionally, painting an entrance hole makes it slick and difficult for a young bird to maintain on a perch.
As for protective clear coatings for box exteriors, consult your paint professional for the best coating to cover the type of paint you applied to the exterior of your box.
Is it worth visually expanding the opening by painting a black “collar” around it, to simulate an opening, so it can be seen from farther away?
I am not aware of any research that has been conducted on this subject. If you happen to know of a study that sought to determine the value of painting a black collar around an entrance hole, please let me know.