Fall migration has ended
Fall migration at St. Marks National Wildlife Refuge is essentially over.
It starts slowly each year in August as arctic-nesting sandpipers, southern-nesting warblers, Swallow-tailed Kites, Blue-gray Gnatcatchers and Purple Martins begin to move.
It intensifies in September as cuckoos, flycatchers and warblers from mid-continent stream through and waves of herons and ibis stop in at St. Marks to rest and feed. By mid-October, the refuge’s winter residents ducks, sparrows, Yellow-rumped Warblers and phoebes start to arrive. Almost all trans-gulf migrants finish moving by the end of October and by late-November most of the refuge’s wintering bird species have been reported.
Migration at the refuge will continue at a slow pace into December when the last Buffleheads, mergansers and Cedar Waxwings filter down. However, the bulk of Fall migration at the refuge is over by late November.
Most migration occurs at night and this year, more than 67-million nocturnal migrants crossed over St. Marks between the beginning of August and the middle of November. Most were smaller birds – warblers, tanagers, thrushes and grosbeaks. However, shorebirds on multi-day flights and some duck species are also included in this number. Migrants were flying at altitudes ranging from a few hundred feet up to two miles above the refuge. A few species were headed west to move into or through Central America. Some species were headed east to travel down the Florida peninsula to winter there or jump to the Caribbean or South America. Many species were making a long Gulf crossing to their wintering grounds.
In September and October, on average, a million birds were moving through the refuge every night. However, birds move on favorable winds and mostly hunker down during bad weather.
On most nights during migration, a few tens of thousands of birds are in the air, but some nights during these two peak months see flights of several million birds. This year, the biggest night flight was on October 8th when 5.8 million birds migrated through the refuge. Not all birds migrate at night. Every Fall, millions of diurnal migrants – swallows, kingbirds, herons, hummingbirds, ibis, falcons, pelicans and hawks – also pass through the refuge. Daytime migrants are generally birds that are large, fast or dangerous. Some daytime migrants are solitary travelers, but many species fly in flocks that may number in the hundreds.
The Fall migrants that we observe at the refuge are a combination of diurnal migrants and an extremely small portion of the nocturnal migrants who pass through the refuge, birds that were too tired to continue their journey and stopped to rest and feed for a day or two. St. Marks wintering ducks are coming in early and at higher numbers than in recent years. Shorebirds are also showing up in good numbers and mixed feeding flocks of wintering songbirds are in the refuge’s pinewoods and oak hammocks. It looks to be a good winter birding season at the refuge.
Fall migration has ended for another year. It’s time you came down to the refuge for some good winter birds.
Don Morrow can be reached at donaldcmorrow@gmail.com.