6/20/2010

Great Blue Heron Rookery: Feeding Their Young

Did you know how LOUD a Great Blue Heron rookery can be during June and July?  I didn't know that a Great Blue Heron rookery (or heronry, which is one technically correct term; heron colony is another)  was noisy because "my" rookery is on an island, and the sound doesn't carry over water.  We visited a different rookery on Friday, and we learned just how deafening these youngsters can be when they're hungry.  The noise is hard to describe; something like a flock of loud quacking ducks mixed in with a few large barking dogs and a Wild Turkey gobble or two thrown in for good measure.  It's deafening!


This Great Blue Heron rookery is not on an island, but it is isolated and fairly inaccessible to snakes, mammals, (especially humans) and other predators by virtue of being in the middle of a swamp and high in the dead treetops.

"Heron species tend to desert nests and entire rookeries if repeatedly disturbed during the periods of pair formation, nest construction, or egg laying" (Buckley and Buckley 1978). The buffer between this heron colony and human civilization is not large, but it is pretty effective.

Certainly the herons seem to be thriving (when seen from afar, at least.) There are many large healthy looking broods. What GBH parent wouldn't be proud of these almost identical twins? (Are all nestlings genetic twins, or is there no such thing as twins in the bird world? I have no idea.)

For the first two months after hatching, Great Blue Heron chicks stay in their nests and are fed by their parents.  If there are three or four youngsters that are almost full grown, like the family pictured above, keeping the chicks fed is a herculean task even with both parents working at it full time. These guys are still getting regurgitated food from their parents, but when they get a little older Mom and Dad will just drop fish into the nest for them to fight over.

1 comment:

  1. Sue, this is so incredibly cool! I've never seen baby Great Blue Herons, let alone a rookery. You go on the best birding outings :)

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