The great blue heron nesting season went by as quick as a flash this year. Fall is when I collect all the HERON volunteers’ data and enter it into the database to get an idea of how the season went for herons (which I will blog about at a later date). It is also a great time to visit colonies on the ground for several reasons: 1) I can usually get a fairly accurate nest count because the nests typically persist into the fall (and most often as long as the following spring); 2) the birds no longer occupy their colonies at this time of year, so I can get real close without causing any disturbance; and 3) there are no biting insects to contend with!
My colony of choice to visit this week was one that is 3.5 hours driving time from my office in Bangor. Sometimes it is difficult to commit to a long day of driving for just one site, but this turned out to be well worth it. The weather was absolutely perfect, the company was very pleasant, hospitable, and knowledgeable, and the site was quite unique as far as heron colonies go. Below is a photo journal of the day’s visit. Hope you enjoy the adventure…

My company for the day: HERON volunteer, Doug Albert.

Paddling upstream to the pond. This colony is in a flood plain setting on the edge of a pond. The easiest way to get there is to paddle up the outlet.

The water was quite low, which meant for lots of scooting over rocks. It also revealed these interesting rock mounds along the way. Many measured 2-3 ft in width and 1 ft in height. We had been talking about the rich Native American history in the area, so we had speculated they were some type of middens. A little more brain storming, searching on Google, and a consult with a fisheries expert back at the office uncovered the truth – they are Fallfish spawning mounds!

Fallfish (Semotilus corporalis) are a very large minnow that build communal spawning mounds that can be quite large. The adults average 12-17 inches in length, and construct these round nests by carrying stones in their mouths. They are primarily considered a bait fish by anglers, but are also eaten by piscivorous birds such as ospreys, eagles, and herons. Perhaps this is a main prey for the great blue herons nesting in the colony nearby?

A first glance at the colony before we round the bend into the pond. See the tiny black blobs in the center of the photo? Those are the nests. The nests are primarily in red maples, but we are peering through an oak stand. During the nesting season, the leaves of the hardwoods almost completely obscure the nests from view.

We counted 24 nests. There were 4 others to the left just outside of this photo that have blown down since June.
That was a great day, It was nice to finally meet our amazing MFW biologist Danielle. DAuria.
Doug Albert
Makes me yearn for spring and the return of the Great Blues.
Getting ready to start trapping GBHEs in NC and fitting them with gps/gsm transmitters. Could be we have Maine birds down here for the winter.
How exciting! That would be an amazing thing to figure out. We really don’t know for sure where Maine great blue herons winter.
will be interested to hear more about this – to know how far some of the GBHEs migrate – and if Maine birds make it that far!
John Brzorad — I’m one of several hundred followers of the Cornell Lab of Ornithology web cam in a GBHE nest in Ithaca, NY. The birds have migrated already, of course. Will you be posting video, pix or at least updates on your GPS project with GBHEs? I think you’d have a lot of interest. I’d be glad to pass the word to the other heron fans on Facebook.
Great job Danielle! I have not seen any herons at Durham bridge this fall, usually they are there when the let the water out. Wonder if there are not as many young his year?