On June 24, I noticed a pair of green herons carrying twigs to a small black willow tree forty feet or so from the Main Wetlands Overlook in Explore the Wild. Four days later there was an egg in the nest. A second egg could be seen in the nest two days after the first. By July 2, there were three eggs.
Two eggs hatched on 19 July. A third hatchling’s fuzzy head appeared above the rim of the nest two days later.
The willow tree is sixty some feet from dry land, although there are numerous other willows nearby. This particular willow has hosted green heron nests in the past, both successfully and unsuccessfully. Several years ago a nest was built within a few feet of the current nest.
The nest was easily visible from the overlook. There are two sets of binoculars mounted on the overlook which facilitated close looks at the nest. Many museum guests were able to get excellent views of the down-covered chicks.
For the next 9 or 10 days, the parent herons supplied the nestlings with regurgitated fish, tadpoles, crayfish, and other locally available fauna. The adults could frequently be seen, wings spread out, sheltering the nestlings from the intense sun and heat. In mere days, the first set of “real” feathers began to show through the chicks’ natal down. The birds began to look beyond the sticks and twigs of their nest, eager to wander along the tree branches of the willow.
On August 2, as I stopped by the overlook to see how the nestlings were doing, the nest was gone. No chicks. No nest material. Nothing.
One adult heron stood on a nearby willow branch which hung low over the water. The bird panted and preened in the hot summer sun.
Having had the weekend off, I hadn’t seen the nest in two days. Young birds grow fast. When I returned to work from the weekend, I fully expected to see nestlings that were well on their way to becoming adult herons. Instead, they were gone.
I can only guess at what had happened to the nest. My first thought was thunderstorms. The previous Sunday night had brought high winds and heavy rain. Perhaps that was what knocked the nest and its occupants out of the tree. The birds certainly weren’t ready to fly, and they most likely couldn’t swim very well. They hadn’t left the site voluntarily.
Speaking with others here at the museum who had also been keeping an eye on the nestlings, the nest and its residents had disappeared sometime between Saturday night and Sunday noon. There were no storms during that period.
I have no proof, but suspect it was a raccoon that destroyed the nest. They can swim quite well, and since I know of a least one parent raccoon with four hungry mouths following her around the wetlands, all of which are eager to learn the tricks of the trade, that’s the scenario I’m sticking with. Among many good reasons raccoons are so successful, why there are so many of them, is their adeptness at climbing, scrambling, swimming, and an extremely varied diet, they’ll eat just about anything. Heron chicks would be quite a treat. A nestling that happened to fall into the water in an attempt to escape the raccoon, well, that individual may have become food for turtles.
Here are some photos from beginning to end.
Whatever it was that happened to the nest, at least one of the parents occasionally revisited the site for several days after the event occurred. I did not, however, see either parent near the nest site after 2 August.