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Gone fishing — with its stealth and sharp beak

PHOTOS BY GARRY BRANDENBURG — A goldfish made the unlucky mistake of swimming too close to the surface of Marshalltown’s Riverside Cemetery pond earlier this week. A great blue heron was standing motionless along the pond edge as this scribe passed by in my vehicle. Spotting an opportunity for new wildlife images, I steadied my 400 mm lens out my window and began recording digital images of the capture, positioning, and swallowing of the goldfish by this large waterbird. Wildlife food chain scenarios illustrate how energy in one form becomes energy for another species.

Great blue herons (ardea herodias) are large long-legged wading birds whose design is to capture fish — or other aquatic critters — by carefully, silently, stealthily, and quietly standing at the ready to locate prey.

Fish in shallow water are a prime target for this bird with a six foot wingspan. This heron species will eat just about anything within striking distance. Its menu can consist of fishes, amphibians, reptiles, small mammals, insects and even other small birds. Those food sources are grasped by the use of strong mandibles which many times the lower bill is used as a spear to pierce the prey, then clamp down on it with the top bill — escape is futile.

How did today’s series of images come to be? Well, stand by for the rest of the story. I happened to be driving past the cemetery earlier this week when on a whim I decided to drive past the pond. One never knows what may be swimming on its waters or passively resting by its shoreline.

A quick scan of the pond revealed little of interest…a few geese, wild and farm types, carousing the area. Then I spotted the Great Blue Heron near the west shore. I was adjacent to the north shore driving west. I gathered my camera and its long lens, checked its settings, lowered my window just enough, and kept driving slowly to the west side where I approached slowly and then stopped.

I felt fortunate that my full frame viewfinder had good light and a good background with the heron in sharp focus. The heron, being a very skittish bird that usually will not tolerate intrusions into its realm, seemed focused on the water as it disregarded my vehicle. I began snapping off frame after frame of what I hoped would become a story of a predator and its prey.

I was at the right place at the right time with the right camera gear to make over 50 images. As the great blue heron stalked the shallow water, its intensity seemed to be in full concentration for something under the surface. I pressed my shutter button and kept it depressed, firing off about five frames per second, with only a few short rests between bursts of the camera’s high speed image capture.

I was rewarded. I was able to capture images of the heron’s “S” shaped neck striking deep into the water while its head was completely submerged as a spray of water splashed outward. Then as it raised its head, a golden color became apparent.

A second later, the bird’s head re-emerged with a goldfish in its beak. I continued to press the shutter, recording the heron walking closer to shore with a continued tight grip on the six inch long goldfish. When the heron was satisfied with its next moves, the bird deftly released and re-clamped its hold on the fish.

Now with the fish head pointed to an awaiting throat, a few quick moves allowed the fish to get closer to the heron’s throat. You can guess that the next few images were of the fish disappearing a little at a time until only its tail was visible, and then I watched as a large lump slipped into the neck of the heron and slowly descended.

The entire episode from the stalking, striking, capturing, positioning and swallowing took approximately one minute. In that one minute, my camera recorded 50 images, and today, you get to see three images of this sequence of a predator interacting with its prey.

Nature in the raw one could say: eat or be eaten. In nature, these types of episodes occur all the time, most outside of our viewing, but we know predators and prey interact all the time. Sometimes, the prey escapes, and a lot of the time they do. But all the predator has to do is be successful every once in a while. The result is life, energy transforming from one to another. Death of some results in life to others. That system has been going on for as long as life has struggled to earn a living in the waters and land surfaces of our very old Earth.

The goldfish became a food source for the heron, and how the goldfish got into the waters of the pond at the cemetery is no mystery. Most likely, a person years ago became a bit tired of their home aquarium and its fishes. I can imagine them taking the aquarium water and its swimming occupants to the cemetery and dumping the contents into the pond.

The goldfish swam away, found its own new food sources and grew larger. Since a goldfish is a close relative of the common carp lineage, it prospered for a few years. That is until it swam too close to the surface where a waiting great blue heron struck gold. Now you know the rest of this story.

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Other wildlife sightings this past week have included a fox snake (elaphe vulpina). I spotted what looked like a stick lying on the gravel roadway. I slowed and identified the “stick” as a snake.

So I stopped, observed and carefully urged the snake to make its way across and into the tall grasses of the roadside ditch. Saving a snake from vehicle tires is something I do if I can. These predators have a nature designed job to do of eating insects, bugs, and small mammals. Fox snakes are a native species of reptile found statewide. When approached, the fox snake will vibrate its tail rapidly, so the sound it makes against dry leaves, gravel or sticks is a mimicking similar to the rattle of a true rattlesnake. Fox snakes as adults can range from 36 to 54 inches long.

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I watched a woodchuck, alias groundhog, run across a rural driveway a few days ago. Its dark rich reddish-brown fur glistened in the sunlight. Its short legs may not be made for running, but this critter does a very good job of making hasty retreats to the safety of tall grasses. Groundhogs are plant eaters, and they like gardens a lot.

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One of the easily observed bald eagle nests got my inspection recently. There was something different about this nest. A careful inspection with binoculars indicates that this huge nest may have become too big, too heavy, and too unstable for the oak tree branches where it was located.

The nest was still intact but tilting at an odd angle. My guess is that a few supporting branches broke, but not enough to allow the entire nest to fall to the ground. Eagle nests do get larger year after year as new sticks are added by the nesting pair. Inside the bowl of this particular nest was a mature bald eagle. I will keep checking this nest to see how the young eaglets grow this summer.

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Fact: one inch of rain falling on one acre of land is equal to 27,154 gallons of water. Multiply that by the number of acres in a specific watershed, and you have a very large number. Slow rainfall events allow time for the soil to soak that life giving water into the soil profile.

Little of that water runs off into creeks and rivers. Slow falling rain is good.

Garry Brandenburg is the retired director of the Marshall County Conservation Board. He is a graduate of Iowa State University with a BS degree in Fish & Wildlife Biology.

Contact him at:

P.O. Box 96

Albion, IA 50005

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