- Blog Post by: T.R. Michels
- June 15, 2012 - 9:39 AM
After researching ducks and geese for several years, and learning that goose pairs will return to the same are to nest every year - and noticing that we had a rare Yellow-breasted Chat sighting at the Fens Unit of the MN Valley Wildlife Refuge, just of of Hwy 13 and I-35W in Burnsviile - and that I had a Common Yellowthroat singing in our backyard three years in a row - I began to wonder if passerines (song birds) renested in the same area in consecutive years.
As I searched the internet for information on the subject, I didn't find much, But, what I did find supported the hypothesis that some songbirds can and do return to the same area to nest in years following a successful nesting the year before. The key words there seemed to be "successful nesting". If a male songbird setup a breeding territory, and a female happened to appear in his territory, and they nested successfuly, it would provide the impetus for both the male and female to return to that area and nest again the next year. But, there are a lot of 'if's" in there.
Since I did not find strong evidence that songbirds mate for life, the whole process depended first on at least one of the nesting pair being alive the following year, and that bird returning to the same site the next year (there is strong evidence that migrating birds have the ability to navigate not only by sight, but also by the elecromagnetic impulses of the earth - which is far more reliable than sighting the sun or moon), and a male bird setting up a breeding territory in approximately the same area as a pair used the previous year, and one or the other choosng a nesting site near the previous year nesting site, based on the habitat remaining roughly the same (no housing or other development), and that temperatures are appropriate (most birders are familiar with blue birds dying of hypothernmia or starvation if spring arrives late) and forage sources are available at the time the birds first arrive (so they recuperate from their long migration) and forage sources available to feed nestlings in the summer (affected by heat, cold and moisture), and no raptors of predators, or humans injuring or killing the birds or wrecking their nests.
Once you have digested all of that - think about bird the size of a hummingbird - migrating thousands of miles from South to North America, through wind or sleet, rain or snow, across mountains, deserts and oceans, (No offense to our Postal Delivery men). It is no less than a miraculous feat. And I for one - have to think that at some point in the evolution of the species - that God had a hand in designing them and giving them the ability to navigate and survive.
Nature is a lot more complicated and fantastic than some of us realize.
Enjoy God's Great Outdoors,
© 2017 Star Tribune