Hawks at a Distance: Identification of Migrant Raptors - Softcover

Liguori, Jerry

Softcover

ISBN 10: 0691135592 ISBN 13: 9780691135595

Publisher: Princeton University Press, 2011

Synopsis

The ultimate field manual for identifying distant raptors

The ultimate must-have guide for identifying migrant raptors, Hawks at a Distance is the first volume to focus on distant raptors as they are truly seen in the field. Jerry Liguori, a leading expert on North American raptors, factors in new information and approaches for identifying twenty-nine species of raptor in various lighting situations and settings. The field guide's nineteen full-color portraits, 558 color photos, and 896 black-and-white images portray shapes and plumages for each species from all angles. Useful flight identification criteria are provided and the accompanying text discusses all aspects of in-flight hawk identification, including flight style and behavior. Concentrating on features that are genuinely observable at a distance, this concise and practical field guide is ideal for any aspiring or experienced hawk enthusiast.

• The first guide to focus on distant raptors as they are viewed in the field
• New information and approaches for identifying distant raptors
• Illustrates twenty-nine species in various lighting situations and settings
• 558 color photos and 896 black-and-white images depicting plumage and shape characteristics
• All aspects of in-flight hawk identification, including flight style and behavior

About this title

About the Author

Jerry Liguori has been studying raptors throughout North America since 1984. He has conducted hawk migration counts at spring and fall migration sites, such as Cape May Point, Sandy Hook, Derby Hill, Braddock Bay, Whitefish Point, and Dinosaur Ridge, and the Goshute, Wasatch, and Sandia mountains. He is the author of Hawks from Every Angle (Princeton).

From the Back Cover

"Jerry Liguori's book takes the hawk identification guide to a whole new level. It is hard to imagine the amount of time that went into this book--countless hours on mountaintops and other hawk-watching sites taking the photographs, then selecting and arranging them. The result is simply the best collection of hawk ID photos ever assembled, combined with Liguori's clear and concise identification tips. This book is a gold mine of information for anyone interested in hawk identification."--David Sibley, author of The Sibley Guide to Birds

"Liguori has done it again. Fresh on the heels of his highly acclaimed Hawks from Every Angle, we now have the new Hawks at a Distance. He never missed a beat. Not only did he pick up where he left off, he has taken it to a higher plane. This twenty-first-century offering does for raptors what the seminal Ducks at a Distance did for waterfowl in the mid-twentieth century. It makes a quantum leap in the complex art and science of hawk identification, taming these shape-shifters like never before."--Clay Sutton, coauthor of Hawks in Flight

"Jerry Liguori presents an innovative concept tackling the age-old problem of identifying flying raptors when seen under field-viewing conditions. Optimal grasp of each species and age class is obtained with a multitude of photographs depicting various flight modes and lighting conditions of dorsal, ventral, and head-on views. The concise text is easy to read and very informative. Liguori's field identification prowess is impeccable and is articulated throughout this guide."--Brian K. Wheeler, author of Raptors of Western North America and Raptors of Eastern North America

"Finally a raptor identification guide that depicts hawks the way you are likely to see them--at a distance! Liguori's unique approach to raptor identification will help birders quickly focus on the field marks that matter, to understand broad plumage patterns, and ultimately extend their reach and abilities as hawk-watchers. This guide is an absolute must for anyone interested in raptors, and will become an instant classic among hawk-watching enthusiasts."--Brian Sullivan, eBird project leader, Cornell Lab of Ornithology

"This book is a winner. The spectacular, cutting-edge photos effectively highlight important aspects of raptors in flight and are simply mind-boggling. This is the one guide that almost everyone will take to the field."--Keith Bildstein, Sarkis Acopian Director of Conservation Science, Hawk Mountain Sanctuary

"Clear and concise, I found all the information presented in this book to be accurate and accessible for both neophyte and more experienced hawk-watchers. I congratulate the author for coming up with such wonderfully illustrative photographs."--Tony Leukering, senior ornithologist, Geo-Marine Inc.

"An intriguing concept--take a few hundred of the most distant, silhouetted, weird angle photos and combine them into a field guide. . . . Very useful to raptor enthusiasts and hawk counters!"--Christian Artuso

Excerpt. © Reprinted by permission. All rights reserved.

HAWKS AT A DISTANCE

IDENTIFICATION OF MIGRANT RAPTORSBy JERRY LIGUORI

PRINCETON UNIVERSITY PRESS

Copyright © 2011 Princeton University Press
All right reserved.
ISBN: 978-0-691-13559-5

Contents

Foreword by Pete Dunne...........................ixPreface..........................................xiiiIntroduction.....................................1Accipiters.......................................14Northern Harrier.................................37Buteos...........................................44Falcons..........................................101Vultures, Osprey, Eagles.........................127Uncommon Migrants and Others.....................157Shapes...........................................171Photo Credits....................................191Bibliography.....................................192Index............................................193

Introduction

Identifying raptors is similar to solving a mystery by piecing together clues. By far, the greatest challenge of raptor identification is naming distant birds. This is because plumage details (and sometimes flight style and structure) can be difficult to judge from afar. Even for the most experienced observers, identifying raptors based on plumage alone can be flawed. With this in mind, imagine how difficult it is to distinguish two species that are practically identical in plumage, like Sharp-shinned and Cooper's Hawks. Even a distinctive plumage trait like the red tail of an adult Red-tailed Hawk can be difficult to view in the field. With practice, it is more accurate to tell similarly plumaged birds apart by shape and flight-style differences than by coloration. I identify most of the distant raptors I see based on shape and flight style, using plumage traits only if clearly visible. Remember, there are exceptions to every rule, so almost no field mark is 100 percent exclusive to one species.

At any hawk-watching site, a close-up bird will draw "oohs" and "aahs" from observers. But because most hawks seen in the field are distant, Hawks at a Distance is a necessary guide. It focuses on distant birds and discusses traits that are truly useful in the field, leaving out certain others that can only be judged at close range. Be aware that some field marks may be difficult to see in the photos in this book. This is done purposely to show how these field marks truly appear in the field. Hawks at a Distance is the first guide that presents birds of unknown identity, pointing out instances when telling age, sex, color morph, or species is impossible, and showing the effect that lighting and molt can have on a bird's appearance. Only migrants that are common across the United States and Canada are covered. Most of the photographs in this book were taken during autumn migration from August 15 to November 30. Birds photographed during spring migration from March to late May or otherwise are noted as such.

I am frequently asked which hawk identification problem I believe is the most difficult. Several come to mind, like telling brown Prairie Merlins from female Kestrels at a distance, ageing Golden Eagles to a specific year, telling a Peregrine Falcon from a Prairie Falcon by silhouette, or telling adult female from juvenile Harriers in spring. However, some aspects of identification are simply impossible due to overlap or similarities in plumages, like telling the race of some Red-tailed Hawks, Merlins, or Peregrine Falcons. Remember, it is enjoyable to simply watch raptors without fussing over their age, sex, or race and that learning hawk identification is an ongoing process.

HOW TO USE THIS BOOK

Hawks at a Distance is designed to show raptors in "real world" settings and help with identification of birds seen with only a quick glimpse. Therefore, the birds throughout these pages are meant to appear distant, unlike most guides that present close-up portraits of birds. Hawks at a Distance presents each species in all light conditions. Each color plate is a composite that includes up to six images and a single caption. They are presented this way so that each color plate is viewed in its entirety as the description is read. Throughout the color plates, birds are shown in poses (i.e., soaring, gliding) in which migrants are normally observed. This is intended to stress the shape features referred to in the captions of certain color plates.

The black-and-white plates portray shape characters for each species pointed out by the accompanying captions. These plates are designed so that the reader's eyes wander around the page and take in the entire page quickly. The text is short so that it is easy to remember and so that the book is uncluttered. Key identification traits are in boldface throughout the text, and memorizing these traits will prove to be useful in the field. For example, the traits in boldface for Golden Eagle are "large, dark bird ... extremely long, somewhat broad wings ... dihedral when soaring, slightly bowed when gliding ... slow moving and steady."

One of the keys to identifying raptors is to learn the basic characteristics of each species well instead of learning the minutiae for each. For example, recognizing the shapes of each raptor, and understanding how they vary under different circumstances, is much more valuable than knowing the eye color of each raptor. Be aware that certain written or spoken descriptions (particularly regarding wing beat and flight style), and even the same field observation between various people, can be interpreted differently. For instance, I once heard the words "stiff," "choppy," "snappy," and "aggressive" used independently by four separate observers to describe the wing beats of a single bird as it flew by.

TERMINOLOGY

Age Terminology

Some age-related terms can be misunderstood or misinterpreted. The terms "juvenile" and "adult" are fairly straightforward and easy to understand (see Glossary), but the terms "immature" and "sub-adult" are sometimes unclear. Even some ornithologists disagree on the exact definitions of these terms. Regardless, the terminology throughout this guide is used in a consistent, practical manner.

The term "immature" describes a bird whose plumage is other than adult. Therefore, an immature bird is either a juvenile or a sub-adult. Some argue the term "immature" relates to a bird's sexual maturity regardless of its plumage. For instance, a breeding accipiter in juvenile plumage (which is sometimes the case with females) could be regarded as an adult because it is producing young. However, age terminology herein defines a plumage as it pertains to field identification, not a yearly age or sexual maturity.

The term "sub-adult" describes a bird whose plumage is a distinct plumage altogether from that of an adult or juvenile. Birds in their first adult plumage (that may have none or several juvenile feathers retained) that are essentially identical or appear identical in the field to successive adult plumages are simply "adults." Most raptors reach adulthood after their first molt cycle starting at about one year old. A few species take about two years, while eagles typically take about five years to reach full adult plumage.

Color Morph Terminology

Throughout this guide, the term "dark" is used to describe buteos that are mostly or completely dark on the underside. This includes birds otherwise known as "intermediate morph" and "dark morph." Intermediate and dark-plumaged birds often appear identical to each other at a distance, which is why both are simply classified as "dark" birds throughout this guide. About 90 percent of dark Swainson's, Red-tailed, and Ferruginous Hawks are truly intermediate birds, but are mistaken for dark birds regularly. On the other hand, intermediate plumages of Broad-winged and Rough-legged Hawks are rare, with dark birds being the norm. I refrain from using the terms "morph" and "phase" throughout the text since they can be misleading, and instead use the terms "light" and "dark" to describe a bird's plumage.

The term "intergrade" describes a bird with a plumage that falls between two subspecies (like Taiga and Prairie Merlins) or between a subspecies and a recognized form of a species (like Krider's Red-tailed Hawk, a pale form of the Eastern Red-tailed Hawk). A hybrid is the offspring of two separate species; hybrids rarely occur naturally, but are commonly bred for falconry.

GLOSSARY

Adult plumage - A bird in its definitive plumage.

Axillaries - Wing pits (see Anatomy).

Bib - A dark patch of feathers on the breast.

Buffy - A pale tan coloration.

Carpal - Underwing area at the "wrist" where all the primaries meet (see Anatomy).

Cere - Flesh between the bill and forehead.

Crown - Top of the head.

Dihedral - Wings held above the plane of the body in a "V" position (see Flight Positions).

Dilute plumage - An overall light tan plumage on a normally darker bird.

Flight feathers - Primaries, secondaries, and tail feathers.

Glide - To fly forward with wings pulled in (see Flight Positions).

"Hand" - Consists of all the primaries, the outermost part of the wing (see Anatomy).

Head-on - Eye-level, front profile (see Flight Positions).

Hover - To remain stationary in flight while flapping (see Flight Positions).

Immature - All ages other than adult.

Intergrade - A bird showing traits of two different races or forms.

Juvenile - A bird in its first plumage.

Kettle - A group of birds soaring together.

Leggings - Feathers that cover the legs and sometimes the feet (see Anatomy).

Leucism - Presence of some or all white feathers on a normally darker-plumaged bird. Sometimes referred to as albinism.

Melanism - Presence of dark feathers on a normally lighter-plumaged bird.

Modified dihedral - Position of wings raised at the shoulder and level at the "wrists" (see Flight Positions).

Molt - Replacement of old feathers with new feathers; usually occurs from April through September in raptors.

Morph - Color form.

Nape - Back of neck (see Anatomy).

Patagium - Area between the "wrists" and body along the leading edge of the wings (see Anatomy).

Primaries - Ten outer remiges or "hand" of the wing; the notched outer primaries make up the "fingers" of a hawk (see Anatomy).

Rectrices - Tail feathers.

Remiges - Secondaries and primaries.

Rufous - An orange-rust color.

"Rump" - Feathers covering the bases of the uppertail coverts (see Anatomy).

Scapulars - Feathers along the sides of the back (see Anatomy).

Secondaries - Flight feathers from the "wrist" to the body making up the base of the wing (see Anatomy).

Sexual dimorphism - Distinct difference between male and female plumages of the same species.

Soaring - Rising in a circular motion with wings outstretched (see Flight Positions).

Stoop - To dive with wings folded (see Flight Positions).

Sub-adult - A bird in plumage (and age) between juvenile and adult.

Subterminal band - The next to last band on the tip of the tail.

Superciliary line - Line of pale feathers over the eye (see Anatomy).

Tawny - Dark yellowish-brown color.

Terminal band - A band at the tip of the tail or wings.

Undertail coverts - Feathers covering the underside of the base of the tail (see Anatomy).

Underwing coverts - Feathers covering the underwing (see Anatomy).

Uppertail coverts - Feathers covering the topside of the base of the tail (see Anatomy).

Upperwing coverts - Feathers that cover the upperwing (see Anatomy).

Wing base - Inner half of the wing from the "wrist" to the body.

Wing-on - An eye-level, side profile (see Flight Positions).

Wing panel - A pale or partially translucent "window" in the primaries (see Anatomy).

"Wrist" - Joint on the leading edge of the wing where the secondaries and primaries meet (see Anatomy).

HAWK MIGRATION

Each spring and autumn, migration occurs across almost all of North America. Raptors move in a broad front, but are known to concentrate along "paths" created by coastlines or mountain ranges. Official hawk migration counts are conducted at many shoreline sites in North America, especially along the Great Lakes, the Atlantic and Pacific oceans, and the Gulf of Mexico. There are popular ridge-top count sites along the Rocky Mountains in the West and the Appalachian Mountains in the East. More than a thousand hawk migration sites are known in North America, and websites exist for many of them. The Hawk Migration Association of North America (HMANA) is an excellent resource for hawk migration sites and migration in general.

HELPFUL HINTS

I cannot imagine how many times I have over-analyzed or second-guessed the identity of a bird only to realize my first impression of the bird was correct. The saying "if it walks like a duck ... it is a duck" is applicable to all forms of birding, so becoming familiar with the shape and flight style of each raptor species is the key to identifying them. For example, most people can recognize a family member or friend from a long distance because they are familiar with the person's figure or the way the person walks. Learning hawk identification through repeated observations is the same concept.

Sometimes birders hear or read about an identification trait for the first time and then apply it incorrectly in the field. For example, I have seen Cooper's Hawks mistaken for Broad-winged Hawks because they "showed tail bands." Another example is relating a plumage trait that only occurs on an adult bird to a juvenile, or vice versa, or noting the manner in which a bird holds its wings in a certain position when it applies to a different posture. Some traits apply to only one species, race, color, age, or sex, while others are shared among species. For example, the topside of the tail on a light Rough-legged Hawk is dark with a white base, but a dark Rough-legged Hawk lacks the white base on the tail. It is a good idea to understand traits thoroughly before relying on them in the field. Remember, it is more helpful to learn the basics of identification well before concentrating on the finer points. For example, birders should learn to recognize a Broad-winged Hawk's relatively stocky, pointed wings, and quick, choppy wing beats, with a secondary focus on plumage.

A good starting point to identifying a hawk to species is to decide what type of hawk (accipiter, buteo, falcon, etc.) it is. While this is often obvious based on structure, at times birds can change shape as they change postures. For example, Harriers have rounded wing tips when soaring, but their wings are strongly tapered and falcon-like when gliding. Also, birds can look and fly differently at ridge sites than over flat lands. For example, Ferruginous Hawks are often buoyant and wobbly along a ridge, but are fairly steady fliers over flat areas. Many birds are seen overhead or above eye level at flat land sites, but are often seen at or below eye level along a ridge. Therefore, experience at both types of sites is helpful.

Birders often attempt to identify raptors as quickly as possible, but studying birds with little concern for naming them "on the spot" aids in learning them. Snap identifications can be accurate only with experience and familiarity. It is also beneficial to watch a bird of known identity as it flies farther and farther away. Keep in mind that it is impossible to identify every bird; making accurate, positive identifications is much more rewarding than erroneously identifying every bird in the sky. I have never met true experts who believe that they know everything regarding identification or can identify every bird they see. Many accomplished hawk watchers are not the most vocal or authoritative persons in a crowd, but often the quiet ones off to the side.

HAWK COUNTING

Whether at a world-renowned migration site or fairly unknown one, counting hawks can be challenging and fun. If one's primary objective to counting hawks is to tally as many birds as possible, then there are certain techniques that will help in doing so. My approach is to focus primarily on birds passing nearby or overhead, and distant raptors secondarily. It requires more time to spot and identify distant birds than it does close birds. Therefore, the more time spent on distant birds, the greater number of birds that pass by undetected. Of course, distant birds should be monitored, but only after any nearby birds have been counted. Many distant birds eventually approach within sight as they pass. I have seen birders point out every "speck" on the horizon while failing to spot many of the nearby or overhead birds.

(Continues...)

Excerpted from HAWKS AT A DISTANCEby JERRY LIGUORI Copyright © 2011 by Princeton University Press. Excerpted by permission of PRINCETON UNIVERSITY PRESS. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
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Edition details

• Publisher: Princeton University Press
• Publication date: 2011
• Language: English
• ISBN 10: 0691135592
• ISBN 13: 9780691135595
• Binding: Paperback
• Number of pages: 208