Around this time every summer the world outside our windows is bursting with life. Vibrant green vegetation with splashes of colourful wildflowers and soon-to-be ripe fruit has thoroughly replaced the long lingering whites of winter and browns of early spring. Insects are abundant with ants, butterflies, bees, and pesky mosquitoes easily found. Alongside these summer treasures comes an important period for our local birds – their babies are all leaving the nest!
Songbirds have evolved to hatch their young this time of year since it is when the most insects should be present. This means that there should be plenty of nutritious food to deliver to their rapidly growing chicks. Even songbird species that typically forage on grain often switch to insect prey to feed their young a protein rich diet for healthy growth.
However, on average, climate change is pushing spring earlier and encouraging earlier plant growth, which in turn might advance peak insect abundances. If our songbirds do not migrate and begin nesting earlier, they miss the opportunity to give their young the best chance at survival with this feast. The LSLBO has a wealth of data on songbirds collected since 1994 which shows some short-distance migrants are arriving sooner, but not many long-distance migrants. What we lack is data on local insect abundances and seasonal trends.
To remedy this, in 2021 we began a new monitoring program focused on insects. It may take at least five years of data collection for this new program to yield statistically sound results, but already our observers have been fascinated by the diversity of creepy crawlies in our forests. Our new program is not isolated to our station, but is part of an international citizen science program called Caterpillars Count! coordinated by researchers from the University of North Carolina.
With the potential mismatch between food source availability and hungry mouths, Albertans may need to take other steps to provide lots of insects to our chicks. One way for us to help is to plant native vegetation in our landscaping whenever possible. Lawns and exotic plant species have defenses which native insects cannot break unlike our native plants whose fortifications have often been overcome by local insects in the age-old evolutionary arms race. Therefore native plants support a higher insect population, which supports more healthy baby birds.
Another way we can help baby birds is to simply leave them alone. After nestlings (which hatch from the egg naked and blind) have grown their body feathers and opened their eyes, they leave the nest. Since their flight feathers are not yet fully grown, they cannot fly very well and are often mistaken for a sick or injured bird. It is at this stage that well meaning people kidnap them from their parents who are still actively providing their high energy diet. It is crucial that their parents are able to teach them to communicate, to find food, and to fly so we need to leave them with their families.
By Robyn Perkins, LSLBO Bander-in-Charge