Animals' Choices To Migrate Or Hibernate


| 2/24/2016 10:39:00 AM


Tags: Migration, Hibernation, Animal Survival, Lois Hoffman,

Country Moonmigration

During the last week of January Bobbi Jo and Barbi, the girls at the State Farm Insurance office, told me they had seen quite a few robins. We in the northern states take this to be a sign that spring is here. Granted, we were having an unusually warm January and I did not doubt their word, but robins in January in Michigan? Yea, I was skeptical.

But then a few days later I saw a robin perched on the rail of my deck and, looking further, I could not believe that the whole backyard was covered in them. However, as I write this article, the temperature is 4 F and there is not a robin in sight. Bet they are all sorry now and each of them is wondering who among the flock had the bright idea to head back to Michigan in January anyhow!

Bird migration and animal hibernation have always been a mystery of nature. How do birds know when to fly south or bears know to crawl in their dens.  I was really curious how they survive all winter without eating (something I would definitely be interested in which would solve the weight issue!). So, I did a little digging.

Bird migration is the regular seasonal movement between north and south along a flyway between breeding and wintering grounds. The main reason for the yearly migration is pure survival. If no birds migrated, food supplies in breeding areas would be depleted, competition for nesting sites would be fierce and predators would be attracted to the easy meals of nestlings in the high concentration of breeding birds.

Knowing when to migrate is basically dependent on birds’ internal stimulus and weather conditions. Natural instinct tells them to go on a feeding binge to add body fat to survive the journey and also to form into flocks. Once the pre-migration flock is formed, feeding continues while the birds wait for suitable weather conditions. They rely on winds north in spring and south in winter to assist in flight. The flocks of many species fly high because of prevailing winds at higher altitudes and because the cold at these heights helps them disperse heat that is generated by flight muscles.

NebraskaDave
2/25/2016 4:42:46 PM

Lois, nature is truly amazing. In another realm of nature the plants know just when to come alive after Winter. Some say it's the day length that tells them when to come out of hibernation and start growing but I find it hard to believe that a flower bulb buried below the surface in frozen ground would be able to tell how long the days are. It's one of those mysteries of nature. The flowering Spring bulbs started sprouting up a full two weeks early here in Nebraska and I too am seeing flocks of Robins which seems a little early for here as well. I'm all for a early Spring. :-) ***** Have a great Spring day enjoying the wildlife.





mother earth news fair

MOTHER EARTH NEWS FAIR

Feb. 17-18, 2018
Belton, Texas

More than 150 workshops, great deals from more than 200 exhibitors, off-stage demos, inspirational keynotes, and great food!

LEARN MORE