April 7, 2017
This morning a group of 15 birders visited the U.S. Marine Corps Support Facility – Blount Island, Dayson Basin, where we drove the length of the 2.5 mile elevated berm around the property. We made five stops for stationary observations. We were greeted by chilly weather conditions with temperatures in the low 60’s (F) plus wind chill; by the end of the excursion the winds had settled down and the bright sun and clear skies had made things a little more comfortable. The area had experienced two days of significant rainfall earlier in the week, but it is unknown to these observers if that had any effect on water levels or conditions inside the basin.
Over a four-hour period the group observed 71 species of birds (a small handful were only observed just outside the gated portion of the property but nevertheless directly adjacent). Species observed that are known to breed locally and appear to be in suitable habitat on the property include Canada Goose, Black Vulture, Turkey Vulture, Osprey, Clapper Rail, Black-necked Stilt, Wilson’s Plover, Killdeer, “Eastern” Willet, Red-bellied Woodpecker, Downy Woodpecker, Blue Jay, Fish Crow, Carolina Chickadee, Tufted Titmouse, Marsh Wren, Carolina Wren, Northern Mockingbird, Northern Parula, Eastern Towhee, Northern Cardinal, Red-winged Blackbird, and House Finch. The group did confirm occupied nests for Canada Goose and Osprey on this visit. We also observed Blue-winged Teal and Ruddy Duck in the basin, two species that have been known to breed in Duval County in very few years historically.
We observed 5 species of waterfowl, including significant numbers of Northern Shoveler (250). A group of 108 American White Pelicans loafing in the middle of the basin is notable for northeast Florida in any season.
Raptors included 3 Osprey, two of which were actively visiting and then defending a nest atop the cell tower. We did not detect any young in the nest. Bald Eagles numbered 6, including 2 adults, 1 third year bird, and 3 immatures.
We recorded 16 species of shorebirds, including 40 Black-necked Stilts, 350 American Avocets, 650 Semipalmated Plovers, and 1,250 Least Sandpipers.
Black-necked Stilts breed in limited numbers in Duval County, but locations such as Big Talbot Island’s Spoonbill Pond are subject to nest predation by raccoons and other predators. The group is encouraged that Dayson Basin appears to provide natural deterrents to such predation (extensive mud, etc.) and are optimistic that the Stilts can breed here rather successfully.
The number of American Avocets using the Basin is simply incredible; the 350 observed this morning likely constitutes the most ever recorded in NE Florida. American Avocets are a medium-distance continental migrant and are known to be less common in spring than in fall migration. Avocet observations in Duval County usually consist of small groups of 5-40 birds in nearby White Shell Bay during low tide in winter. To see numbers of them and in magnificent alternate (breeding) plumage was spectacular.
We observed 4 Wilson’s Plover in the basin; these plovers are known to breed locally at Huguenot Memorial Park and Talbot Islands State Parks. It is possible they breed in the basin, as conditions there seem favorable.
Semipalmated Plovers breed in the sub-Arctic region and we observed 650 or more of them in the basin this morning actively feeding. Stilt Sandpipers winter in central South America and breed in the low arctic tundra; they are very uncommon in NE FL where small groups are usually found at Big Talbot Island State Park’s Spoonbill Pond in migration. The eighteen-plus recorded in the Basin is a high number for the area and reinforces the importance of this location for medium and long distance migrants to recharge.
Least Sandpipers are a common migrant shorebird in NE FL but the numbers today (1,250+) represent an extremely high concentration for the species. The 350 Long-billed Dowitchers noted is also significant; the only other semi-reliable known habitat for them in Duval County is Spoonbill Pond.
The concentration of shorebirds undoubtedly attracts attention, and we observed two falcon species (Merlin and Peregrine) hunting for prey just after dawn. As previously noted, up to 6 Bald Eagles were also patrolling the area. Note: to see 6 Bald Eagles anywhere in NE FL at the same time is another remarkable observation.
The perimeter of the Basin is also well maintained for attracting migrant and resident “land birds”. We observed 20 species of passerine around the 2.5-mile drive.
It is always a noteworthy achievement to record over 70 species in any location in a single visit, and that has only been accomplished in NE FL seven times previous at 4 other locations in Duval County. Dayson Basin is indeed an “important bird area” by any measure.