From the cardinals singing, the doves cooing and the chickadees announcing territories with their calls/of tse-tse-tse, one would think spring has finally arrived. Needless to say, many people know that March can be one of the most grueling months of winter. After all, spring does not officially start until the twentieth of the month. However, in the avian world, the last days of February mark not only the beginning of migration for some birds, but the ringing of the biological clock for others. With the breeding season on the horizon birds are making preparations and there are a few things we can do to help our feather friends prepare.
One of the most important activities we can do to help these nesting birds is provide a spring and summer feeding program complete with a constant source of fresh water. Although natural foods may have been abundant earlier in the season, by winters end many of these products have been either consumed by hungry birds or destroyed by winter snows and ice. Competition for the remaining food sources is elevated just when backyard birds are entering a period of high stress.
In the very near future they will begin to volley for mates as breeding territories are established and defended. At the same time many of these birds will begin their biannual molt to replace old and worn plumage. Molting can hamper a birds ability to move around and forage for food due to the temporary loss of certain flight feathers. Once the molt is completed, courtship begins with some eye catching displays followed by nest construction then egg laying. Upon hatching these nestlings take an incredible amount of attention which will continue even after they fledge from the nest. With all this activity going on one can begin to understand the energy levels needed to have a successful reproductive period. Many of these birds will go on to construct a second and even third nest to rear additional broods, putting an increased strain on remaining natural food reserves. Most of these food sources will not be replenished until late summer or early autumn, similar to the garden produce many people wait to harvest. Supplemental foods provided at backyard bird feeders can directly affect nesting birds, increasing their success rate. Some research shows that with the availability of supplemental feeds many birds appear to nest earlier and quicker since less time is spent foraging for depleted stores of food.
A fresh source of water is a necessary requirement all year long, but especially so during periods of dry weather. Standing puddles created by spring and summer rains or run-off from lawn watering can harbor bacteria and toxins which maybe harmful to birds. A bird bath or avian pond will not only provide a source of on-going fresh water, but attract a variety of songbirds to the backyard for our enjoyment.
Another way we can help, and even enhance our wild bird population, is by providing man made nesting cavities. Loss of habitat and the introduction of non-native birds, mainly European starlings and English (house) sparrows, have led to intense competition for nesting sites among native primary and secondary cavity nesting birds. Woodpeckers, which are the primary cavity nesters, who excavate a new nest site each year. These birds will only excavate new cavities in standing dead timber or in dead tree limbs, not in living trees. Unfortunately dead timber and limbs are removed for firewood or because they appear to be unsightly. Woodpeckers may take up residency in an artificial box if the nest box is of the proper dimensional size. They may also use the box as a winter roost during periods of inclement weather. Secondary cavity nesting birds make up a much larger and more diverse group of birds. Screech owls and kestrels are two common raptors that will use hollows in trees and are also attracted to properly sized and mounted nest boxes. Of course we all know that house wrens have readily adapted to man made Backyard Boxes, yet can be pretty finicky as to which one they will use. Purple Martins almost instinctively search out houses given the Martin house is located in the proper habitat. Chickadees are fairly easy birds to attract into a box that is constructed to the proper size with the adequate opening. And bluebirds have become one of the easiest birds to lure into a nest box, again provided you locate the box in the proper habitat. Other secondary cavity nesting birds that can be lured into a nest box are nuthatches, Carolina wrens, tree swallows and titmice, just to name a few. These and many other birds rely on old nesting sites created the previous year by woodpeckers. However with natural cavities at a premium due to their scarcity, man-made nest boxes have become very popular. Even robins, barn swallows and eastern phoebes will use man-made platforms to nest on provided they are protected from the elements.
Early March is an excellent time to put up nest boxes and clean out old boxes used the previous year, making any needed repairs. When removing old nests dust masks are recommended or try to stand up wind. A light solution of Clorox and water will rid any remaining parasites. If you are installing new nest boxes you may want to use deck screws as opposed to nails when attaching the box to a wooden post. This will make removal of the box for moving and repairing much easier and less likely to be damaged. Nest boxes need to be cleaned out after each nesting so nest boxes with hinged doors are preferred making cleaning and monitoring of nesting birds easy.
Every species of cavity nesting bird, whether primary or secondary, have requirements for nest boxes of a proper dimension with specifically sized openings. Most will appreciate an inch or two of sawdust placed in the bottom. Nest boxes for woodpeckers can be filled with sawdust and lightly tamped. This will simulate the soft heartwood of dead timber as they excavate their new home. Pine sawdust or shavings are recommended. Avoid the use cedar as it is uncertain if they may be harmful to young nestlings. Birds prefer a natural appearance so it is best never to paint or apply a sealer to the nest box. Never paint or apply a sealer to the inside.
Here are some considerations when purchasing a man made nesting cavity; House wrens and purple martins are the only birds which will use free hanging boxes. However orient the door to consistently be facing the same direction or it could lead to abandonment. All other cavity nesting birds prefer the box secured to a tree or post. Nest boxes for various species have certain requirements for habitat and placement. Make sure locate the box in the proper habitat and properly position the house that you purchase for a particular bird species.
The nest box should be constructed of at least 3/4 inch lumber to provide proper insulation. This will also prove to be a more durable product. Also if they are constructed with screws as opposed to staples they will last even longer and be easier to repair. All nest boxes should have a hinged door for easy cleaning, maintenance, and monitoring. Hinged doors make controlling house sparrows and starlings much easier if it is required. It is essential that every box has good ventilation toward the top and proper drainage in the bottom to prevent the device from becoming a death trap for the nestlings. Avoid purchasing nest boxes or feeders made of red wood lumber. Cedar is a more durable material and is a cultivated renewable resource. However, since recycled plastic has become a popular building product, many manufacturers are now using it for nest boxes as well as bird feeders. Long-lasting and durable, easy to clean, with limited manufacturer warranties, these products are the “Going Green” in the birding retail industry.