We saw our first osprey of the spring on Easter afternoon, and our first tree swallows the next day. It is such a pleasure to see these old friends again after their winter absence. But even earlier — in fact, a few weeks ago — we saw our first returning ring-necked ducks on the waters above the third dam on Cobbosseecontee Stream in Gardiner.

Ring-necked ducks are a handsome but poorly named duck. While they do have an insignificant and almost impossible to see narrow chestnut ring around the base of the neck, one of their most prominent features is the bold white ring around the bill. Males have a glossy black back and chest, light gray sides, and a dark purplish glossed head with a peculiar peaked appearance. The female is a more understated but equally beautiful study in tan and shades of brown with a white ring around the eye and the same peaked head shape as the male.

Being poorly named is not the least of the oddities of the ring-necked duck. Here in Maine, ring-necked ducks were quite rare until around the 1930s. In fact, in his 1908 book, “The Birds of Maine,” Ora Willis Knight wrote that the species was a “very rare migrant.” It had been documented nesting a couple of times near Calais but that was the only location in the state where it was known to have bred, and the nearest regular nesting area at the time was in Wisconsin and Minnesota. And then, rather suddenly in the 1930s, ring-necked ducks began showing up and nesting across the northeastern U.S. and eastern Canada. By the late 1930s and early 40s they were nesting in many places in Maine and adjacent Quebec and New Brunswick. By 1946 they had been confirmed nesting in the Adirondacks of New York, and in 1948 they were documented nesting as far north and east as Newfoundland!

The speed of the spread of ring-necked ducks was remarkable, and once the birds arrived in numbers here in Maine, it was decided that more had to be learned about the biology of the species. A major study of the species was established in 1943 at the University of Maine Cooperative Wildlife Research Unit. Led by Howard Mendall, the study continued through 1955. Mendall’s 1958 book, “The Ring-necked Duck in the Northeast,” is still the major source of much of what is known about ring-necked ducks.

While so many other duck species have experienced major declines in recent decades, including the closely related lesser and greater scaup, ring-necked duck populations have continued increasing and are thought now to be relatively stable. In the 1980s ring-necks even expanded their range farther westward, becoming more widespread and abundant in the Yukon and interior Alaska.

Why did ring-necks expand their range so suddenly in the 1930s, and why have they continued to increase while other ducks have declined? Despite Mendall’s in-depth study and many more since then, no one really knows the answer.

The last breeding bird atlas in Maine that was completed in 1983 showed ring-necks to be pretty widely distributed across the state. A new breeding bird atlas is about to be underway for the state, and we will see if they show any change in the distribution of this fascinating species!

Jeffrey V. Wells, Ph.D., is a Fellow of the Cornell Lab of Ornithology. Dr. Wells is one of the nation's leading bird experts and conservation biologists and author of “Birder’s Conservation Handbook”. His grandfather, the late John Chase, was a columnist for the Boothbay Register for many years. Allison Childs Wells, formerly of the Cornell Lab of Ornithology, is a senior director at the Natural Resources Council of Maine, a nonprofit membership organization working statewide to protect the nature of Maine. Both are widely published natural history writers and are the authors of the book, “Maine’s Favorite Birds” and the newly published “Birds of Aruba, Bonaire, and Curaçao” from Cornell Press.