Sunday, April 19, 2009
Is climate change harming loon populations?
Red Lake must have one of the most abundant loon populations in the world but I'm afraid an effect of climate change could be harming them.
These beautiful and inspiring birds can be found nesting literally at every turn in the lake. Nesting loons are highly territorial and will claim all the water in sight as their own. So as soon as you go around the corner (and out of sight of one pair) there is another pair doing the same thing.
Loons are probably the oldest species of birds in the world. Fossils have proven there were loons on earth during the Cretaceous Period, the age of the dinosaurs.
Unlike most other birds, loons have solid bones. This could be a result of their being on the first step of the bird evolutionary ladder. It also lets them sink better than other birds and to dive deeper.
Loon also have the least amount of wing area for their body length. They fly at speeds of up to 90 mph and take off and land exactly as an airplane does -- into the wind.
They truly are a wonder and their incredible calls, from tremulos to wolf-like howls, are the real call of the wild. In fact, the word loon is Norwegian meaning "wild, sad cry."
It would be heartbreaking to see them decline so I hope I'm being a pessimist when I say I see something happening with the weather that is detrimental to loons.
For about the past five years now we've been getting all of our rain in incredible downpours rather than longer rain periods that might last several days as in the past. This is especially true in June, when the loons are nesting.
The result of getting 2-4 inches of rain in a single night instead of over a period of a week is that most of it runs off into the lake before it can be absorbed by the ground. This makes the lake level rise and rise rapidly.
Loons cannot walk on land. Their feet are placed too far back on their bodies. Their feet are almost on either side of their tails. It's one of the reasons they are such great swimmers. It's as if their feet were propellars.
To build a nest a loon stacks water weeds in a pile in shallow water until it is about a foot higher than water level. The loon can push its way on its belly up to the nest which is never more than one loon's-body-length away from the water.
They build their nests in May and traditionally this is the high water period of the year. After all the snow has just melted and drained into the lake. From that point on the water level should continually go down and should be at its lowest just before freeze-up.
The loon usually lays one to three eggs and the pair, which mate for life, takes turns sitting on the nest for about a month before the eggs hatch.
It is during this one-month incubation period that things have been going wrong the last five years or so.
The problem is the heavy spring storms raise the water level and flood their nests. I don't believe one per cent of Red Lake's loons have successfully fledged in five years.
Although most bird species will re-nest if their first nest is destroyed, my observation is that most loons do not re-nest and of the few that do most do not successfully raise young.
So what does this have to do with climate change?
The predictions (and I would have to say "observations" these days) of climatologists is that global warming causes ever-more drastic weather events -- in this case, cloudburst rain storms.
Incidentally, if you don't believe in climate change and don't see it occurring right now it's probably because you don't live in Canada. The effects of climate change are more pronounced the farther north you go. For instance, there's hardly a thing happening in the southern U.S. while the Arctic sea ice and glaciers are disappearing rapidly.
Five years of big storms, of course, are only evidence of weather, not climate. Climate is measured over many decades. So hopefully things will improve in the coming years for the loons.
Fortunately there are still plenty of them on Red Lake. They are a long-lived bird, both individually and obviously, as a species. I just wish they would get a break from the weather and successfully fledge a new crop.