Control Grouping of Green Heron Fledglings on Boomer Lake, Stillwater, Oklahoma 2014

All of the North American Herons in my range are my specialty, however, I have very little experience with the elusive and less common bitterns. Great Blue Herons have been my primary interest for a decade or better, followed by the Green Heron. My experience with the Green Heron has been over the past couple of years, when I gleaned information directly from studying these water birds over the past two years. At that time, I had two herons that came to visit on Boomer Lake in Stillwater, Oklahoma, one that was used to people, the other was skittish and had very little patience.

During spring of 2014, these birds returned for the third season, and this time they had mates, which caused more interest, as I was hoping for a clutch. Both birds appear to have been born here, and returned to their place of birth with their respective mates, who I had never encountered before. I have determined that these birds are in their third season, and never appeared to have mated prior to this spring.

One of the two pair settled on the Southern Cove in late April, which is my actual study grouping. These herons are solitary birds, as the other herons, only together to court, raise chicks and then be on their separate ways. As time progressed and the herons stayed in the area over an extensive period of time, I suspected that they would raise chicks, which they did, as evidenced over the past several weeks. I knew that there was a nest, an approximate location, yet I refused to investigate enough to locate the nest, as I had no interest in dispersing my control group, and risking the health and well-being of the chicks. I heard them after they hatched, so knew that this was a successful breeding with a viable clutch. I suspected that there were four of them.

My suspicions were confirmed in Monday August 11, 2014 when I discovered all four chicks. This was not purely by accident, as at approximately 0705 hours upon my approach to the area, I heard the resident Great Blue Heron adamantly complaining, and I had suspected that I might have Green Heron chicks at this point. This was indeed, discovered to be the case, as I saw one parent in flight, landing in a tree and calling to the chicks, which had been pointed out to me. Three out of the four had successfully fledged, and the fourth on Tuesday, August 12.

The parenting skills of the male and female are exemplary, as they have been teaching the chicks to be successful by both example and by experimentation. The chicks had been chasing after both parents to be fed, which was very short-lived, as the chicks naturally gravitated to doing things on their own with a minimum of instruction. The lone chick continued to be fed, who was out in the open observing and learning, keeping a close watch on its former nest mates. The parents fed it every two-and-a-half to three hours through regurgitation. It kept quiet in its general vicinity, and was able to easily move about in branches, fairly well hidden.

The parents and fledged youngsters were fairly vocal, making no secret of their locations while I quietly observed them. They were learning to hunt for food on their own, and upon discovery of non-food items played with them for a short time, then went about their business to fish and gain sustenance. The parents also fed, provided for the branching chick, and permitted the others to go about their business. None of them were in the same location as the others, and a parent would by a fly-by and periodically call to the chicks who would answer, as they raised their heads to listen to instruction on how to behave. The parents were very diligent, and not once was I chastised for my observation and photography of the youngsters.

The chicks were very adept at both flying and landing, as well as willing to learn and experience new things. They would also get together and play during break times, also including the youngest member of the family where it was located on its branch that conveniently went back to the nest. From time to time, this bird would become tired, and remove itself from sunny areas and retire to the nest when it needed to rest.

On the second day, August 12, 2014, the fourth heron had fledged as expected. The older chicks helped it along, and would check on it when felt that it was necessary. The parents would continue to check on the family, doing occasional fly-bys, but most of their observation was from vantage point in the trees. All chicks would be called to meet with the parents every so often, then they would go their separate ways once again.

Instead of having tunnel vision, these birds paid attention to their surroundings, even to the point of watching people that would pass by their area. Their observation skills are very keen, and their hearing and other senses appear to be quite normal.

All fledglings appear to be healthy and well, no abnormalities that I can see. I will content myself with knowing that I’ll have additional families on the east side of the lake next season. It appears that it can safely be said that these will likely be resident birds in this area.

I might also note, that in this area there was one Black-crowned Night-Heron juvenile that stayed in this area for the coldest part of the winter in 2013-2014. It withstood temperatures as low at 8 degrees F. It would generally be found both perching and in search of food at the water’s edge. It is uncertain if it was also living in this area, as I never saw it come or go from the vicinity.

There was also a resident Great Blue Heron that overwintered, the same bird that has been on the lake over the past couple of years. This heron survived on crappies, sunfish, along with the occasional marsh rat, and most likely other protein when there was surface ice that the bird couldn’t breach.

Additionally, this area gained its own Bald Eagle family, which nested in The Northern Reaches. This was the first year that this area supported a resident eagle pair, who successfully raised young. Winter was very fruitful for the bird population overall, including a number of ducks that would come and go during the winter and spring of 2014. The water table was two feet above normal, which helped sustain plant life at its peak for our part time avian resident population prior to migration.