July birding at the refuge


There is a point in the year at St. Marks National Wildlife Refuge that is like slack water at low tide, when nothing is moving. It is a point when the last of the northbound migrants have passed through and none of the southbound migrants have begun returning. It occurs in latest June and earliest July, just around the time of the summer solstice. The hot air shimmers off the marshes and things get quiet.
Still, there is a lot happening.
It was almost first light when I got to the east end of Stony Bayou II last week. The water level on this pond has dropped, concentrating fish, aquatic insects, and amphibians in the remaining shallows. Birds have moved in to take advantage of the available food. There were almost 200 white pelicans, along with Wood Storks, Little Blue and Great Blue Herons, Snowy Egrets and Roseate Spoonbills. There was also an aerial contingent of Gull-billed Terns and a single Laughing Gull. There were dead fish along the edge of the water, but the birds were going after living prey. I watched and waited until the sun rose before starting my shorebird survey.
In late June, shorebirds at the refuge fall into two groups. First, there are the breeders; Wilson’s Plovers, and Willets. Black-necked Stilts nest in some years and oystercatchers and Killdeer breed here, but they are outside of my survey area. Second, there are oversummering yearling birds that do not migrate in their first year; Semipalmated and Black-bellied Plover, Greater Yellowlegs and Short-billed Dowitcher. These nonmigratory birds are recognizable, because they retain their first-winter plumage until their second year. In late June, the refuge’s shorebird population is about evenly split between the two groups.
It took me five hours of hot counting to complete my route. Miraculously, there were no biting insects. I tallied 176 shorebirds, a little light, but within the normal range for this time of year. In February at the shorebird peak, my total was 4,640 birds.
There were surprises. I had a few individual breeding plumage birds that should have migrated: a dowitcher, a Dunlin, a Black-bellied Plover, and a Greater Yellowlegs. This can happen when a bird’s health prevents it from leaving. The Dunlin had an obviously broken leg, but disease or high parasite loads can also prevent birds from migrating. There was a breeding plumage Wilson’s Phalarope, but this species has complex migration timing and it could be either a late or early migrant. Phalaropes just do what they want to do.
Things are about to change. My next survey will include the first of the southbound shorebirds that are either failed nesters or early nesters that have completed their breeding cycle.
July sees the beginning of Fall migration. Those species that are here only in the summer do not usually have a second brood and some are already beginning preparations for migration. A few, like Osprey, will start leaving in later July. The first trickle of southbound migrants that passes through the refuge in July includes warblers, whose nesting range extends into the south, like Black-and-white, Yellow and Redstart.
Take advantage of the cool early mornings and come down to St. Marks. Fall migration 2024 is about to begin.

Don Morrow can be reached at donaldcmorrow@gmail.com.