It’s that time of year when lots of us get lots of photos of juvenile night-herons with the request to help: which one of the goofy, brown-spotted, sluggish-looking species is it?
That pair — Black-crowned and Yellow-crowned Night-Herons — is one of the many usually more easily identified in the field than in photographs, but given a reasonable shot, there’s a neat trick to quickly distinguish them even if you can’t see any of the generally reliable marks of plumage patterns and soft part colors. We call it The Tilt Test.
Here’s how it works: Mentally tip your puzzling night-heron’s body, all of it, back until the tail tip hits the tarsus, that long stretch of “leg” (foot, actually) that ends in the toes. Be sure to do this only mentally — you could easily lose an eye otherwise.
Where does the tail tip touch the foot? If the point of contact is just above the toes, you’re looking at a Black-crowned Night-Heron; if it’s just below the “ankle,” no more than halfway down towards the toes, it’s a Yellow-crown.
Obviously, this is nothing more than a rough quantification of the “relative” field mark we’ve known about for years, but it’s a quick and easy way to put it into practice without having to wait for the birds to take off to see how much tarsus protrudes beyond the tail in flight. And it’s a lot better than guessing.
If you find this hard at first, practice on adults, which are definitively identifiable with no effort at all. Then go on to the more subtle age classes, and I think you’ll be happy to see how well it works.
What do you think of the two birds in the photographs above?
