LINKEDINCOMMENTMORE

There is no better time to see the world close up and on foot than October. Walking in mounds of leaves with a mild sun overhead and a blue sky is sensing autumn personally.

The last hatch of Monarch butterflies are moving through the Valley. They are the only ones to make the long two-way migration. Their move south is more like birds than insects. The October Monarchs are at least the fifth generation of ones that headed back north last March. This last generation does not have the ability to lay eggs or reproduce. Monarchs emerging at different times of the year do different things, although they all look the same.

The Monarchs cannot survive a cold winter. The winter of 2002 froze millions of them on the winter grounds in Mexico, and the population has been recovering ever since.

Shorter days, cooler air and milkweed aging are cues for the Monarchs to fly south. Decreasing day length is one of the most important factors that cause Monarchs to emerge lacking the ability to reproduce.

Orientation is still a mystery in Monarch butterflies. They start their migratory journey from all over eastern and central North America and end up in a very small area in the mountains of Central Mexico. They do not learn the migratory route from their parents, since only the fifth generation migrates. They rely mainly on instinct rather than learning to find the winter roosts. Their homing system still baffles researchers.

Monarch butterflies migrate during daylight hours using the sun as a celestial cue. Researchers believe the insects navigate using a sun compass in its mid-brain and circadian clocks in its antennae. The sun becomes a compass for them. Researchers also think the insects may use a magnetic compass along with the sun to orient them on cloudy days when they can’t see it.

The Monarchs can’t wait too long to be on their way south because they are cold-blooded, and are unable to fly in cold weather. Fat stored in the abdomen is critical to their winter survival. It is the fuel for the long flight south and it must last until the next spring when they begin the flight back north. As they migrate south they refuel on nectar, and most gain weight during the trip. They conserve fuel during the migratory flight by gliding on air currents.

The Monarch butterfly population has dropped drastically. In 2010 they occupied 9.93 acres of habitat in Mexico. In 2013 that number had dropped to 1.65 acres. Researchers lay the biggest part of the blame on the expansion of crop lands and a big increase in the use of genetically modified crops that are resistant to herbicides.

The U.S. Fish and Wildlife Service sums it up with a grim statistic. Since 1990, about 970 million Monarchs have vanished. Their research work shows that only about 30 million Monarchs remain.

You can help by gardening for Monarchs specifically. You can plant native flowering plants, especially milkweed, to help feed the unique butterflies, and stop the use of herbicides.

To find out more about how to save the Monarch butterflies and other pollinators that migrate through the Valley every year, contact Libba Tracy at libbatom@gmail.com.

There is a new eagle in Grandfather Mountain’s eyrie. It is a juvenile bald eagle named Ajax that is nearly two years old. He was a fledgling in Florida when he fell out of the nest, suffering fractures to the left wing, left leg and right shoulder. Due to those fractures, he isn’t able to fly well enough to be released into the wild. He is also a talker, yelling at most everyone he sees.

If you haven’t seen a juvenile bald eagle, Ajax is worth a visit. For more information, call 800-468-7325.

Wintering sparrows, towhees and juncos are arriving. They like millet in a ground feeder as well as black oiled sunflower seeds.

Male great horned owls begin to hoot and establish fall and winter hunting territories that will turn into nesting territories by January.

Yellow-bellied Sapsuckers return to the Valley to spend fall and winter. They spent the summer at higher elevations nesting.

It is also the peak of fall migration for robins. They move south in large flocks.

Keep out plenty of fresh water for drinking and bathing, and take the feeders in by late afternoon. Bears are shifting territories now looking for acorns which are scarce.

May you always hear the whisper of wings.

LINKEDINCOMMENTMORE
Read or Share this story: https://www.blackmountainnews.com/story/life/columnists/barbara-hootman/2015/10/21/monarch-butterflies-way-south-winter/74338840/