The nesting season is upon us. As I write this, there is snow in the forecast yet the cardinals and chickadees are singing their hearts out. Don’t they know it is still winter? Sure they do.
Just as migrant birds are triggered by day length for their departure times, resident birds do the same for nesting times. My resident cardinal started singing about two weeks ago. He doesn’t sing all the time yet, but he will be steadily increasing his “degree of territoriality” in the coming weeks.
One of the rewards for “riding out” the harshness of winter for a year-round resident is that you can choose the prime nesting sites very early in the season. So early in fact, that you can often pull off a successful nest before migrating birds return to the area.
This early “jump” on nesting also helps guard against events that may interrupt more traditional nesting times. An unusually cool and wet June or an extremely hot and dry July and August can mean no nesting success for those who don’t arrive till late May and leave by late August.
Why don’t they return earlier? It has to do with adaptability and the availability of resources. Birds such as cardinals, titmice and chickadees have varied diets and have proven to be adaptable to changes in their environment. Other species, like many of the warblers, have more restricted diet and habitat needs.
The most common thread among our international migrant is insects. Most go to the land of rich insect life (the tropics) during our winter and time their return with peak food availability for their young.
Why don’t they just stay in the tropics all year long? As abundant as insects are in the rainforest, there still are not enough to ensure the incredible amount needed to raise “all of those young birds”. For that we are very fortunate, just think what life for us would be like if we didn’t have this annual insect extermination team arrive each year.
What can we do to help our nesting friends? For a few like the house wren, Eastern bluebird and black-capped chickadee we can provide man-made nesting shelters. For orioles, we can leave out strands of thread to assist in nest building but for most of the birds, our greatest gift is not to use chemicals in our landscaping. Birds need insects (in large numbers) and we have them.
Do yourself a favor this spring, try to locate a nest in your yard (almost any species but the morning dove) and take some time to watch the activity level when the young have hatched. Try counting the number of trips per minute that are being made to the nest. With a good pair of binoculars, you may even be able to get a good idea of how many “bugs” are being brought back on each feeding run. A few minutes with a calculator and I think you will be quite impressed with your free exterminators!!
By Mark McKellar
SPRING 2003