Hi everyone,
I was asked to keep everyone up to date on the goings-on around the heron nest.
Last Wednesday Karen, our science aide heard a loud bang that startled the adult on the nest. Karen and I were afraid that it may have been a gun shot and that some damage might have been done so we went to the rookery to check things out.
The nest being examined is in good shape and the camera is too. The floor of the forest is littered with egg shells, most of which are clean, suggesting a viable hatch. If eggs contained yolk or remnants of embryo we would have been concerned. We also found three dead birds. These birds appeared to be a little bigger than those in our observation nest. They had very immature flight feathers but they showed no sign of being preyed upon. If they had showed signs of predation we would suspect predation by an eagle or fisher or ????. We also found one old, dead immature bird that had been eaten, but it was too far gone to make any real determination about the cause.
We came to the conclusion that the three dead birds "fell out of the nest". What typically happens in these cases is the larger of the nestlings jostle for the best positions in the nest and force the smaller, weaker siblings to the edge of the nest where they fall to the ground. Sometimes, as the nestlings start to fledge they try to fly/bounce from limb to limb away from the nest. they lose footing and fall to the ground. Some birds (robins, jays, crows etc.) will continue to feed birds that have fallen from the nest, but I don't think herons do. It is unlikely that they would fly through the tangle of branches to reach the ground (they need a lot of flying room).
Karen and I also came across a healthy-looking immature heron, who stood motionless for 15 seconds, then marched behind some stumps. We consequently were presented with a moral dilemma. We could try to catch the bird and take it to the wildlife centre, but the effort of chasing the bird might put it into more danger. But more importantly, to pursue and capture/or not, the immature bird would have put into question our role as "observers". Doing science is often difficult !
I would encourage anyone who, like Karen and I, finds immature herons on the ground in a "study area" leave them alone. If you find a bird elsewhere, let your conscience be your guide.
PF