|Big Lake, Alberta|
On the edge of Edmonton, Alberta, 1000 miles north of us, sits Big Lake, in the Lois Hole Centennial Provincial Park. (links: Prov.Park Big Lake Support Soc. ) The lake is a critically important spot for birds migrating across North America.
Remembering visiting it in midsummer, I am reminded that neither plants nor wildfowl value the same things about places that people do.
My pictures don't show you the mosquitos, but I had to keep moving so they wouldn't land. Yuck, mosquitos. But if you are a bird on a nest in the marsh at Big Lake, they're part of a high quality habitat. Yum, mosquitos.
Likewise, the cattails (most often the common cattail Typha latifolia, cattail family, Typhaceae, same plant that is called reedmace in England) do not care about the mosquitos and happily grow out of what seems to me nasty stagnant water. In fact cattails do so well in standing water that they will crowd out virtually every other plant, forming dense monocultures. Big Lake had a beautiful thick stand of cattails.
In the dry plains, cattail marshes are infrequent and usually protected, as this one is. Cattails are useful edible plants that I would gather if I had access to them. The leaf bases (down inside the leaves) are delicious raw or cooked, young flower stalks can be roasted and eaten and the seeds can be ground into flour. Native Americans wove mats of the leaves.
From the point of view of a duck or marsh wren, cattail marshes are wonderful places to build a nest. Land animals, for example predators like foxes, don't enjoy wading out to find nests and you can hear them coming. Furthermore, the insects in and on the water make great food for nestlings.
During annual migrations, the birds rest on the water in cattail marshes, out of reach of most land animals, finding food in and on the muck below.
Other plants can be found as the land rises and gets drier, but let us turn the other way to deeper water. Here, the plants are not rooted and, in Big Lake this summer, duckweed, Lemna, (duckweed family, Lemnaceae) had taken over. It looks like green scum, but it is an absolutely wonderful miniature flowering plant, with tiny green fronds (leaf-like but not true leaves), incredibly small flowers and thread-like trailing roots. (photos) Duckweeds grow quickly, filling all the open water of still ponds during the summer. Winter kills most of them and then in spring they explode again. Duckweeds are high in protein, in fact, they are raised, dried, and used as cattle feed. Those same characteristics mean they are great bird, fish and turtle food (link).
|The green "scum" is thousands of tiny duckweed plants.|
|Here you start to see individual duckweed plants floating on the water.|
Surrounding Big Lake, the grasslands of Lois Hole Centennial Provincial Park rose up in gently rolling hills...you didn't know there was a marsh until you came over the hill.
There was a time when that was the plains: miles and miles of seemingly flat grasslands and here and there you'd discover an nearly-hidden marsh. Today, we have filled the region with agriculture, suburbia and cities. More and more the marshes are isolated not by grasslands but by human developments. So when you drive down a side street or walk out of your stream hiking trail to encounter a cattail marsh, the water green with duckweed, put on your "waterfowl glasses" and see it as a duck or goose would--as an oasis.
|Cattails and duckweed, Lincoln, Nebraska|
And the converse is true. The cattails and duckweeds of the scattered ponds and marshes of the plains are linked by birds that carry plant bits with them when they fly onward.
Comment and corrections welcome.
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