Animal navigation and migration is mysterious, amazing and critical to species survival. For a human being to try to consider flying almost 3,000 miles with no gear, no compass and no map is hard to imagine. Yet, one has to imagine that the Monarch butterfly does this with a brain a very small fraction of one ounce. How do they do it? Can human beings learn anything about evolutionary intelligence from such examples?
It is thought that animals are gifted by evolution with several adaptations for navigation. Among these are light orienting, using stars, moon and sun. They also use scent and sight, depending upon specific landmarks such as rivers, mountains and forests. Many employ magnetism, including ability to orient according to magnetic field detection. The original versions of GPS, global positioning systems, are found among animal species, and have been studied to perfect the technologies of the human applications of navigation.
The Monarch butterfly typically gathers in clouds of fluttering glory in North America to fly to just one known forest in Mexico called the Oyamel. They descend in numbers of up to 300 million to this one critical habitat. No one knows just how they perform this feat, although orientation by sunlight is considered a critical factor. What may be even more astonishing is that the Monarch’s offspring, even unto the fourth and fifth generation, know how to find a very specific tree, the “family home” in which they winter.
The grey whale is a good deal larger than a butterfly, but they also are looking for an escape from winter cold when they migrate a world record 20.000 miles from the Arctic to the warm waters of Baja. Here they give birth to babies who have just a few short weeks to prepare for the arduous journey north again. Other marine animals that migrate include salmon and turtles. The theory has long been that they have the ability to scent with olfactory signals along the way, but recent research suggests they also may have an uncanny ability to use magnetic fields that they detect along the way.
Birds are just as fantastic at migration. U.S. East Sand Hill Cranes travel thousands of miles south to find warmth and food, as do flamingos in Africa’s rift valley. The Bar-headed goose braves the dizzying height and weather of the Himalayas to get to India each year. Arctic Terns travel up to 10,000 miles, from North Pole to South. They are small birds, but the Terns are in almost constant motion for this trip, even their re-fueling, diving for food in the ocean, does not allow them a rest stop.
Also in the far north, polar bears, caribou, wolves, and musk oxen all herd in large numbers to follow the call of the mild, that is, for milder weather and more abundant food sources. Arctic regions are particularly vulnerable to navigation hazards increased by altered ecology due to climate change.
Then there are bats of many kinds and regions that read the signals of nature to flock in dark clouds, often using echolocation, the warmth and light of the sun and even their limited vision to pinpoint destinations with crucial accuracy.
Migratory animals are extremely intriguing and even inspiring, but they are also under threat. During most migrations is when animals are most disrupted by pesticides, pollution, hitting buildings, fences, highways, dams, turbines, development and more. Upon at last reaching their destination, lost habitat, increased agriculture and ever more marginalized tracts of wilderness are found. To preserve science, bio-diversity and just the natural beauty and wonder of earth for all migratory and navigating species, more conservation and education is necessary.
