By Dan Groebner

Isn’t it supposed to be spring cleaning?! Not if you are helping some of our feathered friends by providing needed nutrition or a humble abode to raise a family next spring.

Songbirds aren’t singing, eagles aren’t stealing fish from osprey, and dusky grouse certainly are not drumming from their territorial log podiums at this time of year. But there is still plenty of avian activity to keep us occupied by both migrating and the hardy year-round residential birds of the White Mountains.

Fall and early winter are the ideal times to set up your bird feeders and clean out your birdhouses. You say you don’t have any birdhouses? Then now is a great time to make or buy a few and put them up right away so they have time to “age” and acclimate to the area. Birds that readily take to human-built homes include mountain and western bluebirds as well as wrens and Arizona’s smallest falcon, the colorful American kestrel. These birds, among many others including some of the small owls, require cavities and holes hollowed out of trees to raise their young as they do not build or use nests themselves.

Cavity nesting birds are great examples of animals finding unique, “unoccupied” housing arrangements by taking advantage of holes in trees that naturally rot or were hollowed out by more capable birds like woodpeckers. These cavities are most often found in dead and dying trees, called snags or wildlife trees, that don’t have much left for branches, so nest builders can’t find the right kind of real estate in these trees.

Even though we have a pretty good idea of how to build a birdhouse that might actually be occupied, it’s best to leave as many natural snags in the woods for nesting habitat if they don’t pose a hazard from blowing down.

Just like humans, different bird species have different preferences for home styles. As you can imagine, smaller birds like bluebirds prefer the tiny home variety with a small “door” (1.5” diameter) while kestrels and screech owls require a much larger box with a proportionally larger entrance hole (3” diameter). Bluebird boxes are likely to be taken over by cowbirds or sparrows if the entrance hole is not just the right size. Cowbirds are also known for laying their own eggs in another bird’s nest, called brood parasitism, forcing the other mother bird to raise her young.

Plans for building birdhouses for different species can be easily found on the internet. Make sure you check a few sites and plans to find the most popular and successful one. Or you can buy pre-built boxes through sources like Acorn Naturalists. 

Some birds, like kestrels, require some type of “nest” material in the bottom of the box, like wood shavings or small sticks to keep eggs from rolling around. Other birds, like bluebirds, are the princesses of the winged world and prefer to do their own interior decorating starting with a clean box to build up with their own nesting materials of grasses, needles and small twigs gathered nearby.

Years and years of monitoring hundreds of bluebird boxes have shown that the boxes most used were cleaned out after the last breeding season. It appears that nest building is a required step in the egg-laying process and since there is only so much room within the boxes, pairs can only prepare one or two nests in each box before the nest materials start spilling out of the entrance hole. 

Maintaining bluebird and wren houses is usually pretty easy as they don’t have to be mounted high up in a tree. Many of these boxes can be mounted on fence posts spaced evenly along fencelines in ”bluebird trails” making it easy and efficient to visit them for cleaning.  It’s best to install kestrel, owl, and bat boxes at least 10-15 feet above ground level to give these larger critters the more altitude they need for take-off and to make it more difficult for predators to find them. So you’ll most likely need a short ladder to safely and conveniently get to the boxes to check for use and clean them out.

You can be part of a citizen scientist project by submitting your monitoring information to organizations that have been keeping track of nest box data for years nationwide. For bluebirds and other songbirds, check out the Cornell Lab of Ornithology’s NestWatch website (nestwatch.org), data forms, and instructions to upload your data. The Peregrine Fund’s American Kestrel Partnership does a great job of tracking kestrel box use throughout the US and also has valuable information on making your box more appealing to kestrels (kestrel.peregrinefund.org). Both of these sites make your data available to researchers, educators, and others who are curious about bird box nesting.

Even the best-made boxes sometimes do not get used the first couple of years they are available, so don’t get discouraged if you find your box in the fall as clean as the day you put it up. Be sure to report even the boxes that do not get used as this might help with designing better boxes and monitoring bird populations.

After you get all your boxes cleaned and you’ve submitted your nesting data to a database, it’s time to get back to observing birds up close from the convenience of your home. A strategically placed bird feeder in front of a window where you spend time during the winter can be its own daily soap opera of drama between the dainty black-capped chickadees and the aggressive Stellar’s jays until the squirrels show up and chase everybody off! That’s one reason many people spend extra money on bird feeders that are “squirrel-proof."

The vertically oriented tube-type feeders can be hung from a line between two trees so that squirrels have a harder time getting to them. Sometimes it’s impossible to keep them off of the feeders completely, so some folks design their setup so the squirrels will provide Olympic-quality gymnastic moves trying to get to the feeder all without the benefit of a soft landing mat!

Platform-type feeders where you just place the seed on a flat board are used by a wide variety of birds but need lips on the edges to prevent excess seed from spilling off. Squirrel raids on these feeders could have you refilling daily so they need to be placed far from trees used for take-off points and up on a tall, un-climbable pedestal or post. Since these feeders can collect moisture even though they have drain holes, a regular maintenance schedule is needed to prevent birds from getting sick. You definitely don’t want to use one of these types of feeders during the summer, as all of the seed spilled over the edges will attract bears, javelina, skunks, and maybe even some more uninvited guests.



With all of the migrant birds passing through our area or settling in for a relatively mild winter, you could be busy with identification at your feeders in the fall and spring. When we get our hopeful winter storms, you can look at it as a time to build some more affordable bird homes to be deployed as soon as the roads open. The internet always has valuable information on birdhouse projects (if you look thoroughly enough!), but you can always contact the local Game and Fish Department office for more advice and possible locations to place your boxes. Please note that birdhouses placed on the National Forests need to have permission from the local Ranger District office, so contact Game and Fish or the Forest Service prior to putting them out.