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The Great Blue Heron

The Great Blue Heron
The majestic Great blue heron can be found on 3 Creek Ranch just about any time our lakes and ponds are free of ice. I particularly enjoy watching them from the covered bridge as I arrive on those early summer mornings, the heron standing motionless in shallow water, that intensive stare, and if I wait long enough, I’m lucky to see the heron extend its neck back then strike at an unassuming prey with near-lightning speed. With several gulps, the prey is down the hatch and the process starts all over again.

So I was more than delighted last week when Priscilla Sibson invited me to see the heron rookery, or ‘heronry’ to be more exact, in the South Park Wildlife Management Area. Standing in the pouring rain with binoculars in hand, we so thoroughly enjoyed watching not just one heron nest with two beautiful nestlings, but more than 21 nests containing over 45 nestlings all clumped together in three adjacent cottonwood trees. Somehow, this was a wildlife spectacle that reminded me of time I spent in East Africa, and here it was not five minutes from my Nature Center office! Only days later, I was again invited to join Toni and Michael Brownfield, Carole and Ed Leibzeit and Priscilla to revisit the heronry…with a spotting scope, binoculars and again, the rain. As we watched this incredible display of nests built literally on top of one another, all of us came to ask the same question: ‘what’s the advantage of nesting so close to one another?’ Our first, and easiest assumption to make is that we’ll only find colonial nesting birds where an abundance of prey or food is available to the birds…there must be enough for everyone or they simply wouldn’t be there in such high numbers. Next, by having abundant food within only a few miles or so of the heronry, less-adept herons might be able to follow more successful foragers when they leave the colony to feed. If our group were herons, I’m afraid I’d be the one always watching and following the more-adept Carole and Toni…I would continually return to the colony empty handed only to follow the wise and experienced once again on a successful foray. But then again, herons typically forage alone, so what does this say about the colony serving as a ‘Carole, Toni and Priscilla information-center’ for inept herons like me? Colonial living might offer an unsuccessful heron like me the benefit of learning opportunities…assuming the more-experienced herons are better able to find food. However, if herons like me are always following them around to the good sites, I present more competition for those resources. So this begs the next question, why do the more-experienced herons continue to hang out and nest in colonies with unproductive herons all around them? I certainly don’t have the answer, but my guess is the ol’ safety in numbers idea is in play, and that nesting in greater numbers means a greater chance that the eagle or vulture will eat your neighbor and not you. In fact, colony nesting might far outweigh the implications of catching a few less frogs due to competition with your more-inept colony mates who followed you to your favorite hunting grounds. And here’s where Michael and Ed step in…being the more-dominant herons they are, perhaps they’re able to acquire the safest nest site within the colony (one might assume this to be in the middle of the colony rather than on the fringes). We certainly shared a lot of laughs, witnessed one of the baby herons fall completely out of the nest only to stand up shaking its head, probably so darn mad at its sibling for that overly aggressive nudge. We watched a bald eagle fly and hover for a minute or so right over the colony, and then watched four Turkey Vultures appear as if out of nowhere, all flying right adjacent to the colony, swooping low over the nests and actually perching in the colony…all of which sent the nestlings into a cacophony of noise and chatter. I can only imagine the words being spoken…maybe it really does take a colony!

All my best,
Roger Smith
Resident Naturalist

Great Blue Heron Photo: This photo licensed under the Creative Commons Attribution ShareAlike 2.5 License.