Go seeBirds
Ducks arriving at Great Meadows in Concord through late autumn
When: October to December
Ducks keep arriving on eastern Massachusetts freshwater marshes long after the songbirds have gone, because cold and hunger move them rather than daylight. At Great Meadows in Concord the refuge does it on purpose: the pools are drained in summer to grow a crop of seed-bearing marsh plants, then reflooded slowly through the fall so the rising water knocks the seed off the stems.
Why this time of year
The refuge's own management plan describes the autumn reflooding as feeding dabbling ducks through fall migration and winter. Drakes are also at their best: they spend late summer in drab eclipse plumage and moult back into full colour, which Mass Audubon dates from the end of September to mid-November.
How to notice it
- Start at the observation tower by the Concord unit parking lot on Monsen Road and scan before you walk anywhere. There is an entrance fee at the Concord unit.
- Sort the ducks rather than counting them. Birds that tip tail-up in the shallows and never disappear are dabblers; birds that vanish underwater and surface somewhere else are divers.
- Walk the Dike Trail between the two impoundments to the pier partway along, which overlooks the lower pool.
- Go back after a hard cold snap or a strong north wind. Flocks arrive on weather, so the marsh can look empty one week and hold hundreds the next.
Try this with kids: Find a duck that shoves its whole front half under and leaves its tail sticking straight up. Count the seconds before it comes back.
an impoundment is a shallow pool held behind a built dike so staff can raise and lower the water on purpose
Safety
- The dike is a narrow path with open water on both sides. Keep small children in hand.
- Never walk out on marsh ice. It sits over mud and plant stems and is not reliable.
Sources
- govinfo.govUSFWS Final Comprehensive Conservation Plan for Great Meadows NWR, January 2005. Water levels are drawn down in alternating pools in Concord during the summer, then slowly flooded during the fall and early winter, providing carbohydrates and fat for the higher maintenance requirements of dabbling ducks during fall migration and winter; the rising water gradually knocks the seeds off the plants onto the surface. Verified verbatim from the extracted PDF text, not from a fetch summary.
- fws.govUSFWS visitor page: open sunrise to sunset, an entrance fee applies at the Concord unit, an observation tower is accessible from the parking lot, and the Dike Trail runs between the two impoundments with a pier partway along overlooking the LOWER pool. The page names no self-pay station and no upper pool, so this entry names neither.
- massaudubon.orgMass Audubon, Explore, fall 2022: from the end of September to mid-November drake waterfowl are in their most colourful breeding plumage; 27 duck species are regularly present in Massachusetts in fall or winter; 18 dive and 9 tip up. This is the only Massachusetts-specific timing source here and it is what bounds the plumage claim to September through mid-November.
- audubon.orgAudubon: fall migration is often late in the season, as waters freeze or the food supply is depleted. This is the basis for the southbound tag and for the cooling trigger.
- audubon.orgAudubon: main fall migration much later than most, mostly October to early December. The only source giving a month range, and it names no peak.
- fws.govUSFWS refuge overview: two large impoundments used by ducks, geese and shorebirds; mallard, black duck, wood duck and blue-winged teal common; refuge bird list over 220 species.
- audubon.orgAudubon on the eclipse-moult reversal: male dabbling ducks moult out of drab late-summer plumage into their finest for autumn courtship. National rather than Massachusetts, so the local Mass Audubon window governs the dates.
Checked against these sources on September 6, 2026.
In the guide for October, November, December