In North American field guides, loons and grebes share pride of place, at the front of the book.
The birds are closely related.
That's why they share space.
Most bird books are arranged taxonomically, with related species pictured near one another.
The order is fixed, too. The most primitive birds occur first. In this context, "primitive" has to do with the structure of the birds.
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Loons are familiar birds, but they are not common. Perhaps 12,000 occur in Minnesota - the largest loon population of any state except Alaska.
Grebes are far more widespread.
To find a loon ordinarily requires a trip to a woodland lake, although loons do sometimes occur on prairie wetlands, most often in spring migration.
Grebes might be encountered on woodland lakes, as well as prairie potholes. Indeed, almost any pothole deep enough for a modest dive might have a pair of grebes, and some potholes host hundreds of nesting pairs.
Six species of grebes occur in our area.
The pied-billed grebe is ordinarily a solitary bird, and its overall numbers are not as great as some other species.
Yet, pied-billed grebes are perhaps the most frequently encountered member of the tribe, at least in the Red River Valley. They occur in ditches and potholes. I've also seen them on the Red River and in ponds on the Grand Forks Greenway.
Once disturbed, the pied-billed grebe pulls a disappearing trick, simply sinking into the water. This has earned it the name "helldiver."
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The pied-billed grebe is a bit smaller than our smallest duck. But it shouldn't be mistaken for a duck. A close look shows a bird much plainer than any of the ducks, even the hens.
Pied-billed grebes are brownish overall, tending to gray sometimes. The bill is distinctively different than the bill of a duck, thicker and more cone-shaped.
On prairie potholes, especially those ringed with aquatic grass and cattails, two other grebe species are common. These are the eared and horned grebes, closely related and quite similar species.
Both are slate gray to light black overall with chestnut or reddish bellies. This is more prominent in the horned grebe, and the color recurs on the neck.
Both horned and eared grebes have prominent feather clusters on the head. In eared grebes, these appear delicate, almost wispy; in horned grebes, they are solid and so more prominent.
My guess is that eared grebes are the most numerous grebes in North Dakota. On favorable sites, they can be abundant.
Horned grebes strike me as less gregarious, though they may occur in substantial numbers, too. They just like a little more space.
The largest of our grebes is the western grebe. This is also the grebe that most resembles its relative, the loon.
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Western grebes are two-toned gray on top and white on the bottom. They have very long necks and long, pointed bills.
Clark's grebe is very similar, so much so that it was overlooked for decades and was accepted as a separate species only recently. The most telling difference is in the face pattern, more black in western, less black in Clark's grebe.
Western grebes require deeper water and larger lakes than the other grebes. They're common on Devils Lake.
The sixth grebe species is more like loons in that it prefers wooded lakes. This is the red-necked grebe. In North Dakota it is common only in the Turtle Mountains, though it sometimes shows up elsewhere in the state.
Red-necked grebes also occur in Minnesota's lake country, but the species is really a denizen of Canada's forestlands.
Loons and grebes have been much on my mind since officials of Minnesota's Department of Natural Resources worried aloud about potential impacts of the oil spill in the Gulf of Mexico.
Most of Minnesota's loons winter on the Gulf coast, and so do some mid-continent grebes. But grebes disperse more widely than loons. Some migrate to the Atlantic coast, some to the American Southwest and some go only far enough south to find open water.
So, the threat to them is less than it is to loons.
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Mike Jacobs is editor and publisher of the Herald.
