Wednesday, August 17, 2011

Least Bittern and Glacier Ridge

One of central Ohio's birding hotspots this summer has been Glacier Ridge Metropark on the northwest side of Columbus. This is the view from the observation tower. We are fortunate that Franklin County Metroparks is very advanced in their thinking regarding land management and habitat restoration. The agency has restored acres and acres of wetlands in this area, producing fabulous results.

If you want to learn more detail about the Glacier Ridge wetland restoration, CLICK HERE for a column that I recently wrote for the Columbus Dispatch.

This slough is ground zero for a hefty collection of very rare breeding birds for the central Ohio area, and in some cases ANYWHERE in Ohio. Our rarest rail, the mighty King Rail, bred here as did a small army of Sora and Virginia Rails. Pied-billed Grebes and American Coots have nested, as have many species of more common fare. Dragonflies, butterflies and other insects abound. Interesting native wetland plants are popping from the seedbank in prodigious numbers.

And to think, this land was in corn and beans a decade ago. In the business of wetland restoration, it's all about location, location, location. This area is on the eastern fringes of the formerly vast Darby Plains prairie and this region once harbored many prairie sloughs that would have been full of birds that are now imperiled in Ohio.

Photo: Bruce Miller

I was saving the (arguably) most interesting Glacier Ridge breeder for last. Bruce Miller, who is an outstanding photographer based in Columbus (his website is HERE) was kind enough to share his stunning Least Bittern shots with us. The Least Bittern is the smallest heron in the Americas, and is quite the rarity with us, now being listed as threatened in Ohio.

Photo: Bruce Miller

This is a great photo and reveals a few things about the foraging abilities of the Least Bittern. One, note the size of those feet! Those long toes and roughened soles are great adaptions for clinging with ease to the stalks of cattails. The ability to grip plants growing in water that would be too deep for the tiny heron to wade in allows it to exploit a much wider spectrum of feeding opportunities. It should also be noted that Least Bitterns favor large, often nearly monotypic stands of cattails, and that such luxuriant growths are not a bad thing in a marsh. While big cattail stands are not a rare thing, there are far fewer around than there once was and a number of marsh-breeding bird species are thoroughly adapted to this habitat.

Photo: Bruce Miller

A Least Bittern can compress its body to impossibly slender dimensions. If the situation warrants, the bird can pancake itself to a width of about one and a half inches. It's no secret how they slip through seemingly impenetrable stands of cattails.

One of these birds weighs about 80 grams - less than a Common Grackle. Least Bitterns are also normally quite secretive and can be incredibly difficult to glimpse. Their throaty cuckoo-like calls are often the only clue that they occupy a marsh. But these Glacier Ridge birds have been incredibly extroverted and score of birders have seen them.

But Bruce's great photographs allow us to study this fascinating little heron in ways that field observations seldom will, and I appreciate him sharing the fruits of his labor.

3 comments:

Heather said...

Thanks for highlighting Glacier Ridge. I was not aware of how young this wetland is. What a success story! Hopefully as it continues to mature, more and more birds will be drawn to it, and perhaps birds like the Least Bittern can begin to recover their populations in the state.

Auralee said...

I have visited the OSU research wetlands off and on, but I have not found it very birdy. This sounds fantastic. Are the birds you mention in the post still there this time of the season?

Jim McCormac said...

Still there, but get there soon! The show won't last much longer.

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