A few years ago I took a 2 day raptor workshop with the author of the Peterson Field Guide to Raptors of North America. Bill Clarke taught us the field marks for all of the raptors common to our area, including the field marks necessary to identify males, females, and juveniles of various ages. He was dismissive of the idea of "holistic" bird identification: what does it even mean to look at 'the whole bird'? How does that help if you don't know all the small differences that distinguish different species?
Peter Dunne explains.
Field marks are the details of bird plumage and structure that can be used to distinguish different species of birds. They were originally derived from the study of "skins", the preserved stuffed remains of dead birds stored in collections like that held in UBC's Beatty Museum. But not all field marks are easily seen in the field. For example, why are ring-necked ducks called ring-necked ducks and not ring-billed ducks? Why a "sharp-shinned" hawk? Apparently the answers to these questions are obvious to anyone who's studied a skin, although the names are puzzling to those of us who use binoculars. And are the field marks the first thing you see when you see a bird? Actually, probably not. The first things you probably notice are actually things that you may be taking for granted. Where are you seeing the bird? What habitat is it in? What's the time of year? What's the size and general shape of the bird? What is it doing? How is it acting? These factors are the most obvious things you see when you are looking at a living bird in its natural environment, and are factors you can use to help identify birds.
Dunne recommends becoming familiar with 'families' of birds first: what are the characteristics of ducks as opposed to sparrows as opposed to herons? See, even if you are not a birdwatcher you have some idea of what these bird families are like and how knowledge of a bird's environment, location, and general appearance can help you start the process of identifying a bird's species.
From there you need to spend as much time as possible observing the bird to gather additional clues as to who the bird is. Only then is it time to consult a field guide to compare the bird's location, behaviour and yes, field marks with those outlined in the book to figure out just who you were looking at.
Dunne's book is a great introduction to the art of bird identification. It has tips to help the rest of us develop the skills that are so automatic to experts like Bill Clark that he doesn't even recognize that he is using them.
