I regularly work with the Long Point Bay Land Trust during the field season and this has given me plenty of great experiences in helping to protect and conserve Southern Ontario wildlife. Last week we cleaned out wild bird nesting boxes in preparation for the return of migratory birds. The boxes were built and placed in habitat suitable for native bluebirds, in the hopes of fostering a population of these elusive birds.
Nesting boxes are a common sight throughout Southern Ontario as farmers and birding enthusiasts install them along fields and woodlands. The bluebird suffered a serious decline in the mid 20th century due to various factors, including pesticide use and loss of habitat. Bluebirds are cavity nesters and have several requirements for where they will set up housekeeping. Unfortunately, the bird boxes that are provided for them are prime real estate for many other species of birds, necessitating that they be emptied and cleaned yearly of the previous inhabitants nests.
Sparrows, starlings, and house wrens will all take over the nesting boxes, and some birds will even take over a bluebird’s nest and lay their own eggs. We sadly found evidence of this in some of the boxes, with the original bird’s eggs pushed to the bottom of the nest box. These eggs had partially developed embryos inside. The invading bird then laid and hatched it’s own clutch in the stolen nest.
We found nests containing a variety of natural materials, from the usual grass and twigs, to waterfowl feathers and moss. One ingenious bird had even woven a piece of discarded plastic wrap into her nest. I found that each nest told a story; about the species of the bird who made it, about the success of the hatch, and about the dramas that unfold in the bird world.
I look forward to monitoring the bird boxes throughout the season and seeing what new life emerges. We can only hope that we did well in the eyes of the bluebirds and will be rewarded with their approval.