Each of this year’s two visits to Prairie Island Indian Community were a week later than usual due to previous commitments by our hosts and guides, Community biologists Brad Frazier and Gabe Miller. This did not affect the first set of surveys but there was probably some reduction in bird activity by July 9-12 when we conducted the second survey. Making this even more likely was the heat that scorched the region during the weeks between our trips. Fortunately for us, though, the days we were on site were lovely and mild.
Rain had fallen to the north so the river was in a period of changing water levels that made it difficult to access a few places. The islands, whose very character is dictated by the vagaries of the Mississippi River, are sometimes easily accessible by the boat so we can reach the exact point from which we count. At other times, the water is so high we can often reach those points or get very close to them from the boat. On several occasions this year we encountered something in between. The water had receded enough so that we could not float to our exact spot but not decreased enough for us to reach the island by foot. Rather between us and the islands were mudflats that were just too soft and deep to make it possible to proceed. So we conducted the surveys from the boats, which really does not make any appreciable difference in the results as the islands are pretty narrow anyway.
The most significant bird we have had over the course of our surveys has been the loggerhead shrike, a pair of which nested in 2010 and 2011. There was some fear that the bison herd kept at another portion of the community land might be moved to the prairie where the shrikes nested, but that plan has been abandoned. So even though there had been no change in the habitat, the shrikes had still for some reason left the site. Bob Russell, of the USFWS, told me that shrikes were found during the ongoing Breeding Bird Atlas not too far away so they might return in the future.
Last year the yellow warbler was encountered at more points than any other species. This time, with a presence at 23 points, its rank had fallen considerably. More widespread were American redstart, eastern wood pewee, house wren, and red-winged blackbird. This years most ubiquitous bird, however, was the American robin recorded at 41 points. The drought probably accounts for the more restricted occurrence of the yellow warbler.
At least one bird was at all time high. Dickcissels tend to arrive later than other species but even so last year we never even saw one on our first visit and only 7 on our second. This year, though, things were completely different: on our first visit we had an amazing 66 and on the second visit 35. This is characteristic of the species, though, as noted by Kenn Kaufman in his wonderfully informative Lives of North American Birds (1996): “Very erratic in summer occurrence; they may nest in large numbers in an area one year and be totally absent there the next, presumable as a response to rainfall and its effect on habitat.”
There was a modest mayfly emergence but the mosquitoes were a bit heavy particularly on our second visit. One morning before donning my head net, I made the mistake of opening my mouth and ingested quite a number, an augmentation of the day’s protein ration. I figured they can’t be too unhealthy as they were probably loaded with the blood from me or my companions and no one ever talks about vampires suffering from high cholesterol or diabetes.