Tuesday, March 19, 2013

Phenology 3.19.13

Although it appears winter will never pass, the transition ahead of us from late March to April marks a significant shift in temperatures. The average low temperatures go from 20° in March to 35° in April. These changes in low temperatures are what spurs maples to start running sap, causes tree buds to swell and even mark the bloom of our first spring flowers.

The anticipation of spring is nearly unbearable, but signs of new life are all around us and increasing daily! Of note, a family of Tundra Swans was sighted flying over the farm yesterday. The winds were blasting from the Northwest at around 30-35 mph, and it was cold, yet this group of magnificent birds were making short time flying field over field.

Annually Tundra swans migrate 3,725 miles from their breeding grounds in the arctic circle to their wintering areas in the Southwest United States/Northern Mexico. How birds know how find their nesting areas and wintering areas with no GPS is somewhat of a scientific mystery; there are some strong arguments that navigation by stars, the sun, magnetic fields and mental maps play a role.  We do know that length of day is what triggers the start of migration. With some of these ideas making sense, still it is almost impossible to explain how some birds can figure out migration. Take for instance our MN State Bird, the common loon--annually the two loon parents visit the same water body for their nesting grounds and may have a clutch of chicks. After an entire summer on the water, these chicks are left alone in late fall, as their parents have already taken off migrating to the Gulf of Mexico.  These young, only months-old loons somehow decide to take flight and head South to the warm wintering waters of the Gulf with no map, no GPS and no parents to guide them! In my opinion it is these triumphs of nature that keep me interested; I do not necessarily need to scientifically prove how or why  it works to enjoy the fact that there are just some amazing feats that are a mystery.

On these quiet winter evenings at hand one can hear the calls of the Great Horned owl and the Eastern Screech owl in the distance. This time of year is when these owls are pairing up and getting ready to start a new family. I urge you to step outside for a few minutes each evening this time of year and listen for these raptors--this is the season when they are most vocal.

With the cold weather still upon us, these little signs of spring and new life put things into perspective and keep the will strong to begin another growing season on the farm!


No comments:

Post a Comment