Friday, May 10, 2013

Bexley's famous night-herons

A pair of Yellow-crowned Night-Heron nests adorn massive Sycamore trees overarching Preston Road in Bexley, Ohio, on the east side of Columbus. This species has been nesting in this spot for about eighteen years, and insofar as I am aware, it is the only known breeding "colony" of Yellow-crowned Night-Herons in the state. They are undoubtedly nesting in a few other locales, but pinning down the nests is often not easy.

This is a ritzy neighborhood indeed. Nearly all of the neighbors are well aware of the herons, if only because of all the birders that flock to the neighborhood to pay homage to these special birds. Or, perhaps, they notice the ever-increasing layer of white guano that whitewashes the street below the nests. Ah, a small price to pay in order to host such interesting animals

I made my annual trip to the nests yesterday, and was pleased to see that a pair of birds was back in residence. Their clumsy stick structure is a bit rattier than the surrounding big $$$ homes, but it has done the job well for many years now. There was no sign of another pair, and the other nest remains unused. The active nest is the one in the backdrop in the previous photo.

Yellow-crowned Night-Herons are at the northern cusp of their breeding range in Ohio. A few birds have nested even farther north, such as in Michigan and Minnesota, but for the most part this is as far north as they make it. The species becomes quite common southward, and is easily found in the swamplands and coastal wetlands in the southern U.S, throughout the Caribbean, in much of Central America, and parts of South America.

Oh my, what big eyes you have! The bulging reddish eyes of Yellow-crowned Night-Herons are a major, obvious feature, and serve the animal well on its nocturnal fishing forays. A beautiful little stream, Alum Creek, flows very near to this nesting site, and these birds undoubtedly spend much time in its waters under cover of darkness.

This shot shows the peculiar forward-facing arrangement of night-heron eyes. Actually, most herons have a similar setup. It's as if the bird has a pair of telescopes sighted down the blade of a bayonet. Like a pool shark carefully measuring his shot, a hunting heron draws a bead on prey, and with a brutal thrust of the neck that is quick is a wink, it spears its victim. In the case of Yellow-crowned Night-Herons, the favored prey are crustaceans, and in these parts that means crayfish. Life for the "crawdads" in nearby Alum Creek is perilous indeed.

There was much primping of plumes as the birds set about the task of rehabilitating their nest. The sexes look nearly identical, and I believe the male is the bird on the left, fanning its feathers like a peacock. When nest construction commences, he gathers sticks and offers them to the female, who then carefully places them into the structure. This behavior, apparently, serves to also reinforce their pair bond. That's what I observed yesterday - male passing along sticks, female embedding them in the nest.
The male partially fluffs himself into a regal state, and seems to demand that the female pay him some mind. She was busy, though, and had seemingly sent him out on a limb where he couldn't interfere with her important work.
It won't be long and eggs will be laid, and before we know it the gangly youngsters will be in the nest. I'll try and make another trip down here at a later stage and share how things are going for this pair.

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