This is the time of year when shorebirds are becoming more attracted to Ridgefield National Wildlife Refuge, and at times, in a big way. The lakes and ponds at the refuge are now dwindling in size with mudflats taking their place. It is from this time through October/November that shorebirds will be a common sight at the refuge.
In North America there are at least 50 types of shorebirds that frequent its shores and mudflats. This does not include the vagrants that are blown off course by storms and high winds. They range in size from the small 6” Least Sandpiper to the largest 24” Long-billed Curlew. (This year Ridgefield NWR was host to both of these birds!) Although some classifications differ, shorebirds generally include Sandpipers, Godwits, Jacanas, Stilts, Oystercatchers, and Plovers.
Shorebirds are found throughout North America primarily along the edges of bodies of water. Some prefer salt water and can be found along sandy and rocky beaches and mudflats. There are others that will be found feeding in salt water and fresh water, depending on the season. There are also a few that generally will be found in grassy pastures away from bodies of water.
Food sources for shorebirds are similar. They feed on insects, aquatic invertebrates, mollusks and small fish. Most walk(run) along shores and mudflats probing for food with their thin sensitive bills. The length of the bill varies considerably so differing species can work the same shore and obtain different food supplies. They also sort themselves into preferred feeding habitats. Least Sandpipers feed on insects in drier marsh mud while dowitchers probe the substrate in shallow water for mullusks. At the same time the yellowlegs feed in deeper water, snatching small fish from the surface. At times, though, you will find many of the dowitchers and yellowlegs competing with the peeps (small sandpipers) for their food supplies in the marsh mud of the shoreline.
Shorebirds are some of the most difficult birds to identify. Because of their closeness in coloration and size, some species are very difficult to tell apart except for their calls. Most species will change colors dramatically from the breeding season to the dull, drab colors of fall and winter when it becomes especially difficult to properly identify separate species.
Ridgefield NWR is fortunate to have at least 15 species of shorebirds that come to the refuge on a regular basis each year. Some of the more common ones are the Least and Western Sandpipers, the Greater Yellowlegs, the Long-billed Dowitcher, the Killdeer and the Wilson’s Snipe. Perhaps a little less common are the Pectoral and Solitary Sandpipers, Dunlin, and the Lesser Yellowlegs. Then, of course, from year to year, there are always the rare and accidental shorebirds that stop in for awhile and cause a lot of birding excitement. Among these quite rare, accidental ones that have shown up at the refuge over the last year have been the Long-billed Curlew, American Golden Plover, and the Sanderling.
Next time you come to the refuge, look out on the mudflats with a good pair of binoculars and check out the shorebirds that no doubt will be there. See how many you can find and compare that with the Weekly Bird Sightings List on the web at http://www.ridgefieldfriends.org/bird-sightings-last-week.php.
Some of the other uncommon/rare birds that were seen this past month at the refuge are the Redhead, Horned Grebe, American White Pelican, Red-shouldered Hawk, Semipalmated Plover, Olive-sided Flycatcher, Black Phoebe, Warbling Vireo and Lazuli Bunting.