Everyone loves a mystery. Birders are no exception. So for those among us who enjoy what are probably unsolvable mysteries, the early ornithologist explorers of North America left us a few.

Just recently, we read about one that we had never heard of. It is the story of a bird that naturalist William Bartram described from a trip to Florida in the late 1700s — what he called the “painted vulture.” Although dismissed for centuries as a misidentified crested caracara (a well-known species that still occurs in Florida), a recent paper by two ornithologists provides historical evidence that they believe shows that Bartram’s bird was a real, but sadly now-extinct, species.

Audubon himself gave us almost a treasure trove of mysteries, including at least five birds that he painted, named, and included in his famous publications. Ornithologists have written about and debated what these birds might have been for over a hundred years, and writer-naturalist Pete Dunne has even written a charming fictionalized story about a birder who rediscovers one of them, the small-headed flycatcher, in the New Jersey pine barrens.

It seems the modern consensus on Audubon’s other mystery birds like the carbonated warbler, the blue mountain warbler, Cuvier’s wren (a kinglet, really) and Townsend’s bunting, is that rather than being species that went extinct since Audubon’s day, these are all various hybrids, plumage abnormalities, or poorly executed paintings. But of course we don’t really know for sure and will likely never know. The Townsend’s bunting is the only one of these creatures for which an original specimen still exists. The bunting has been attributed to be an exceedingly rare plumage variant of a dickcissel. Maybe someone will do a DNA analysis at some point to prove it.

Audubon gave us in Maine a somewhat different kind of mystery. He described a new bird species, the “tufted auk” — what we now call the tufted puffin, from a specimen that was shot by a hunter at the mouth of the Kennebec River in the winter of 1831-32. Tufted puffins, we now know, occur only on the Pacific Coast of North America. Many ornithologists and birders over the years have understandably questioned whether somewhere in the process Audubon had gotten the location wrong. And who knows? But last year a tufted puffin astonished everyone when it showed up and was well-photographed on Machias Seal Island off the Maine coast — the first record of the species on the Atlantic Coast of North America since Audubon’s! Some mysteries, like that one, can’t be solved, but at least they can be savored and shared.