By David Hawke – It has been said that winter is the time for planning ahead, supposedly because you have all this idle time on your hands. Ha! But okay, maybe it is the time to prepare for some Spring-related things.
Perhaps you have been operating a bird feeder these past few months, providing a snack of sunflower seeds or suet to those hardy species that didn’t evolve properly to migrate the heck out of here for the winter. However, I’m sure the blue jays and chickadees have certainly enjoyed your handouts!
Any species of any critter kingdom needs four basic ingredients within their chosen habitat to survive, those being food, water, shelter and space. By space I mean territory or area in which they can find enough of the other three ingredients to sustain themselves without intense competition with their neighbours.
Overcrowding due to the lack of enough space quickly leads to a shortage of food, water and shelter, which then leads to spread of disease and a drastic reduction in population. (Hmm, why does that scenario sound so familiar?)
Okay, back to that bird feeder and all your spare time. As the temperatures rise and Spring beckons in a luring manner on the seasonal horizon, the birds will soon be arguing with each other as to whose nesting territory your feeder is located within. If you’re going to set up an avian ‘tavern’ you need to be aware of the ripple effect.
So now I suggest you turn your attention to housing. Many species of birds like to nest inside a hollow tree, this cozy shelter providing them protection from both weather and predators. But how many old, hollow trees do you have in your yard? I’m guessing not many, probably none. Here’s where you can get busy with a bird housing assistance program.
Chickadees like to nest in cavities of trees, as do tree swallows, bluebirds, wrens, flickers, wood ducks and kestrels. You may not have enough space to attract all of these birds, but even a moderate-sized back yard can become home-base for a wren. (Wrens are great at picking your garden clean of bugs.)
Nesting boxes have been utilized for decades as a way of keeping birds within easy viewing distance while at the same time providing a service to their chances of survival. There have been dozens of books, brochures, and now websites devoted to nesting boxes, each stating that every species of bird has very specific size requirements of the box.
Two sets of dimensions are critical to the potential success of attracting a bird family to use your nesting box: the diameter of the entrance hole and the interior dimensions. Too big and the birds may not feel cozy, too small and certain species will be restricted from entering. You have to match your potential tenant’s expectations with your pieces of wood and building plans.
A tree swallow or bluebird prefers the front door to be 1.5 inches in diameter with the interior being five by five inches, while a house wren likes the hole to be just an even one inch, with the bedroom only four by four inches. Yes, birds are a fussy and demanding lot. There are also concerns as to the depth of the box, as fledglings must be able to hop up from the nest to the exit without exhausting themselves.
You may have noticed that I’m suggesting that you build said nesting boxes. While I acknowledge that not everyone has a full and heated carpentry workshop set up in the garage or basement, there is also a lack of retail outlets that carry a full line of nesting boxes. Believe me, I’ve looked. A few fancy garden boxes that are more pleasing to the human owner’s eye than to a feathered would-be tenant, and any actual functional boxes are in the price range of $60 to $80. Ouch!
So maybe find a local kid whose shop skills are burgeoning, or a seasoned carpenter who likes to put together little wooden boxes. Scrap ends of pine boards work just fine as building material.
Whether you buy or build, there is another aspect of any nest box that needs your attention: the clean out door. Some birds will have more than just one family per summer, and some birds will like your perfect nest box so much that they will want to use it again next year. Like any B&B operator, you have to clean things up a bit between visitors.
Unfortunately, many commercial nest boxes come completely sealed, which is fine for weather protection and one-time use. However, to clean out the old nest and debris, a side or top or door must be built in for a proper cleaning. Note that rarely do you have to add material within the bird box, that chore being more for wood ducks and screech owl boxes (in which case you use wood shavings not sawdust, and pine shavings not red cedar).
Cleaning out the boxes is a wintertime duty that can actually become a bona fide reason for you to get outside. Note that mice will often overwinter in the boxes, so maybe wait until the snow is beginning to melt and the mice move out on their own.
While writing this I looked out the window and noticed there are snowflakes falling, so I guess the bird feeders should be topped up. While I’m out and about I’ll take a look in the wood shed for a few extra boards to slap together a new box or two. Keeps me busy.
Dave’s Notebook: And another week roars by... Today's topic (bird nesting boxes) may seem a little premature, but the future tenants are already preparing for their northwards flight. Time to make ready for them.
© 2021 David J. Hawke