It’s now mid-November and the images of swallows flocking in August as they prepare to migrate are distant memories. Yet the fall migration still continues. The fall spectacle is a wonderfully protracted event.

The schedule of bird migration is largely governed by food. Migratory birds leave Maine when their preferred food is no longer sufficient. The first to leave are the aerial insect-eaters like swallows, swifts and nighthawks. Leaf-gleaning insect-eaters like warblers, vireos and tanagers are next on the calendar. Caterpillars and other insects on which these birds depend can be found through September. Few warblers linger into October.

Sparrows occur throughout October as the seeds of grasses and other plants are available for these ground-feeders. Most sparrows will depart before the first snows cover their food.

The migration we are enjoying now is waterbird migration. As long as lakes are unfrozen, these birds can find the sustenance they need.

Fall birding on lakes and ponds can be exciting. You never know what you might see. In late October I took one of my two ornithology lab sections to Sabattus Pond, a known hot spot for ducks and other waterbirds in autumn. The first day we saw the expected buffleheads, ring-necked ducks, greater scaup, lesser scaup, ruddy ducks and American coots.

The next day those same birds were present but a student pointed out a group of birds in the middle of the pond. Several hundred dark ducks were arranged in a line, a common behavior in black scoters. Sure enough, that is what they were. The orange bills of these birds seemed to be illuminated from within.

The flock took flight and we were able to pick out two white-winged scoters. Bill Hancock saw these birds later near sunset. He watched the flock fly south from the lake, making this sighting a one-day wonder.

Black scoters nest at high latitudes on small ponds. They winter along the coast. The hopscotch migration of these seaducks gives us a chance to see them on freshwater bodies.

In early November, a smaller flock of black scoters and white-winged scoters visited North Pond in Smithfield. They were accompanied by a few red-necked grebes, another species that winters along the coast.

On Nov. 6, Tom Aversa and Bruce Barker found some remarkable waterbird diversity on Sebasticook Lake in Newport. They saw the expected freshwater species like Canada geese, mallards, American black ducks and green-winged teals. But if you just saw the rest of their list, you would certainly think Tom and Bruce were birding at a coastal site. They saw common eiders, black scoters, white-winged scoters, probable surf scoters, long-tailed ducks, a red-throated loon, a red-necked grebe, four horned grebes and Bonaparte’s gulls. As is normally the case, these coast-bound migrants did not linger. Striking it rich with fall waterbirds is a hit-or-miss proposition.

On that same day at Lake Josephine in Aroostook County, Bill Sheehan found a greater white-fronted goose among the 800 Canada geese there. He was also able to find two cackling geese, a miniaturized version of the Canada goose.

November can be a good time to see vagrant species. On Nov. 1, Derek and Jeannette Lovitch, Kristen Lindquist and Evan Obercian found a gray catbird and two orange-crowned warblers in Portland.

On Nov. 7, Lisa Dellwo and Bill Schlesinger found a yellow-billed cuckoo in Lubec. On Nov. 9, Don Reimer found a blue-winged warbler at Sebasticook Lake.

Although none have been reported this year to my knowledge, cave swallows occasionally appear along the New England coast in November. The closest breeding population is in east Texas.

The big excitement this November has been the Franklin’s gull at Lake Sebasticook, present for several days. This vagrant from breeding areas in the Great Plains provides the 10th record for the state.

Herb Wilson teaches ornithology and other biology courses at Colby College. He welcomes reader questions and comments at:

whwilson@colby.edu