by Tom Wetmore
About a month back I was asked and then subsequently volunteered to conduct a series of surveys of North Pool by canoe, performing marsh bird callback counts. Friday evening, May 13, 2005, Lu and I did the first of the series. We entered North Pool near the overlook an hour and a half before sunset, paddled directly down to Hellcat, and then did ten playback stops as we returned north. We did our first playback at 7:00 pm and the last playback two hours later around 9:00 pm, a little over an hour after sunset.
Our playback tape had five species, Black Rail, Least Bittern, Sora, Virginia Rail, and King Rail.
This was the first time Lu and I had ever done a survey of this type, and we had little idea of what to expect or what might happen. As the evening progressed we became increasingly encouraged as we heard more and more marsh birds, and got furtive views of a few. We were amazed to find at least one more target bird at each of the ten survey spots. Here is a list showing the marsh birds recorded at each survey point. The points are listed in reverse order because we visited the points in this order.
The results of the first survey were the following:
We also encountered a noisy flock of 12+ Black-crowned Night Herons that arrived while we were paddling to Hellcat, and that we disturbed back into flight two hours later while surveying.
We heard no evidence of larger rails, King or Clapper. Our tape did not include Pied-billed Grebe, American Bittern, or Common Moorhen calls. We did not hear Pied-billed Grebes or Common Moorhens. However, both Pied-billed Grebes and Common Moorhens were observed in the North Pool on both May 14th and 15th.
Though not surveyed, noteworthy were the numbers of Marsh Wrens and Gadwall in the North Pool. Marsh Wren territories were densely packed, especially throughout the south two thirds of North Pool, and we were often surrounded by three or four singing males while stopped doing counts. I would estimate that we traveled by 40 Marsh Wren territories, though this number could be much higher. The number of Gadwalls we saw agreed with Rick Heil's description of North Pool as a "Gadwall factory" in 2004. One of the pairs of Canada Geese encountered were escorting a brood of just-hatched downies.
Nearly all of our observations of marsh birds occurred in Phragmites (not surprising, since the entire pool is dense with the stuff), but indicates that Phragmites are not completely bad when it comes to supporting these birds.
Because we were very busy with all the minutia of paddling (fighting stiff breezes from the north most of the time), trying to identify survey sites, manipulating boom boxes, clipboards, and wet paper, there was little (in fact no) time to just relax and enjoy the setting. However, paddling through the pool was as near a religious experience as I can imagine. We were struck by the sheer size of the pool, and by the incredible resource that this large body of fresh water on the island represents. We were also struck by how complex the North Pool is in terms of its complex system of waterways and mini-islands. Though we concentrated mostly along the reed edges opposite the dikes, we did enter into a few of the waterways that meander through the pool. The system of waterways could be explored for days, and we realized that our survey just touched the surface of what's there in the pool.