The little birdies and the big birdies and all the in-between birdies are returning to the North, and the bird watchers are all atwitter.

As well they should be.

The birds come in one or twos, or in flocks numbering in the hundreds. In fact, if you were to add them all up, millions of birds from dozens of species are all part of the spring migration.

The news media was full of stories about the solar eclipse, an event which lasts a few minutes, but are strangely silent about the much bigger incredible bird migration, which lasts for a month or more. Some of those birds have flown hundreds and even thousands of miles to be a part of it. They fly here to feed, breed and raise their young before migrating south again before the winter snow comes.

This spectacular natural phenomenon is even more impressive when you look at the history of it all. Around 14,000 years ago, the last ice age was ending. Most of Canada was covered by a gigantic glacier that was two to three kilometers thick in places. So, there wasnSA国际影视传媒檛 much of a migration because itSA国际影视传媒檚 hard to find food and nesting places on top of a glacier. When the ice age ended, a big melt began that lasted hundreds and even thousands of years.

As the glacier melted, it exposed the land of outcrops and glacial till. The lichens and mosses soon started growing, followed by grasses and willows. Slowly, this provided food and nesting spots, and the insects, mammals and birds moved north. More and more of them followed the melting ice until eventually we have the ecosystem of today. This illustrates how wildlife adapts to a changing environment.

Sometimes people talk about the retreating glaciers, which is a bit of a misnomer because they donSA国际影视传媒檛 move backwards, they melt. In the process of melting, they produce a whole lot of water, which raises water levels in lakes and the oceans. Around the world, melting glaciers probably flooded a lot of ancient stones cities and villages near the coast.

Now between 11,800 and 8,300 ago, glacial lake McConnell covered Great Bear Lake, Great Slave Lake and Lake Athabasca, with the Laurentian ice sheet forming its eastern shore. Lake McConnell covered 240,00 sq. km. As a comparison, Great Slave Lake only covers 27,700 sq. km. Yellowknife is an interesting place because we have clay sediments from Lake McConnell, and we also have sand deposits left behind by a major glacial river that flowed under the glacier. You can follow those sand deposits all the way to Gordon Lake and then out to the barrens.

So, if you were a bird watcher back then, I am sure you would go see the glacier to the east of us but no doubt the geese, ducks and other birds would return each spring and fly south every fall. That is the other thing people seem to ignore. While the ice age was over, this was still the North with frigid winters and warm summers. Apparently, in the last two million years we have gone through five ice ages. ItSA国际影视传媒檚 no wonder that the horizon looks flat with all those glaciers passing over us. Just imagine what it would look like if someone had of documented it all.

Nature is endlessly fascinating because there is so much to learn about, and I am always a little amazed that the governments donSA国际影视传媒檛 learn more about the past. This explains how we got the sand deposits in town and how we got the clay in other areas, which people often get stuck in when it gets wet.

So, enjoy the spring and the big melt, and the next time you go for a walk, try to see how many different species of birds you see. Also, with the nesting season starting, the birdies are going to get rather noisy.