Read an Excerpt
In Search of the Ivory-Billed Woodpecker
By Jerome Jackson HarperCollins Publishers, Inc.
Copyright © 2006 Jerome Jackson
All right reserved. ISBN: 0060891556
Chapter One
Behavior and Ecology
How It Might Still Live
Structure is for function.
Without saying a word, my teacher wrote this phrase on the blackboard. It was the first day of class, and I was a fourteen-year-old freshman at a new high school. I was looking forward to one thing: biology. I loved nature, but I had never really thought about the relationship between an animal's physical structure and its behavior and ecology. "Structure is for function" became a mantra, a mystical formula that opened my eyes to the world around me. It taught me to ask questions. And I applied that questioning to my study of the ivory-billed woodpecker. Why does an ivory-bill have feathers covering its nostrils? How does its barbed tongue work? Why are its tail feathers curved from base to tip? Why are its eggs so shiny and white? My questions seemed endless, but how could I find answers?
Understanding the behavior of a species that is extinct or so rare that it can no longer be studied is a challenge. It requires depending on every shred of evidence available from those who have studied the species, as well as circumstantial evidence from every available source. I am extremely fortunate to have had James Tanner'spublished doctoral thesis on the species come along when it did, more than six decades ago in 1942. It may well have been the last hope for really understanding the complexity of the relationship between the ivory-bill and its environment. Tanner's observations play a major role in this first chapter. In a sense these observations are like the cardboard frame associated with a child's jigsaw puzzle: pressed into that frame are the outlines of all the pieces, thus aiding us in getting the picture right.
I felt much like a child as I began studying ivory-bills. To decipher the natural history of the ivory-bill I examined every bit of information I could find, including Tanner's descriptions and photographs, artwork drawn from life, interviews with the few who I truly believe have watched these birds, anecdotal accounts, specimens and pieces of specimens, and inferences from my own knowledge of this and other woodpeckers. With each piece of the puzzle I found, the picture became clearer. To be sure, some of the pieces are missing. And perhaps I have a piece or two upside down or out of place. But I can see a wonderful mosaic of adaptation in this exquisite bird.
A Social Bird?
Bayard Christy suggested in 1943 that the ivory-bill was a social species and that its courtship was communal.1 I am inclined to agree that they are social, at least as woodpeckers go. In some ways the ivory-bill seems a parallel to the cooperative-breeding red-cockaded woodpecker and perhaps also to the acorn woodpecker (Melanerpes formicivorus).2 For both of these species there is a natural resource that is concentrated and abundant enough that sharing among group members is possible. In the case of the red-cockaded woodpecker, the resource is the cavity. Cavities excavated into living pines take considerable effort to complete and may involve the work of multiple birds over a period of years. Once completed, these cavities are safe nest and roost sites that can be passed on from generation to generation. In the case of the acorn woodpecker, the resource is the store of acorns. The social behavior of ivory-bills might be linked to the large cerambycid beetles these birds seem to favor. Such beetles are found concentrated in large, recently dead trees, and discovery of and access to those beetles may be facilitated by group effort.
The largest reported number of ivory-bills ever seen at one time was eleven.3 I can hardly imagine the sight of eleven ivory-bills in one scene, but such it once was. Four of the woodpeckers were foraging in the same baldcypress tree (Taxodium distichum) during winter, the others nearby, in the late 1800s near Florida's Gulf Coast. Others have often referred to small groups of ivory-bills. John James Audubon, for example, in his journal entry of December 14, 1820, noted that he saw five ivory-bills feeding together. His classic painting of three adult-plumaged ivory-bills feeding amicably together reinforces an emphasis on sociality. In 1935 in Louisiana, George Lowery watched two males and two females feeding on the same dead tree. He wrote, "In manner and disposition the birds are very quarrelsome, although only in a vocal way."4 Such is also true of the highly social red-cockaded and acorn woodpeckers. In 1948, John Dennis and Davis Crompton observed a group of three ivory-bills, two of which were incubating at a nest, demonstrating this sociability among ivory-bills in Cuba.5
Flight
Ivory-bills are known not only to feed together but also to travel together over great distances in their searches for suitable feeding sites. Tanner discussed many aspects of ivory-bill flight, noting that it can vary greatly. His observations were more extensive than those of most other observers and were less anecdotal. From him we learn that ivory-bills have a strong direct flight similar to that of a northern pintail (Anas acuta), with steady, rapid wing beats. When traveling any distance, he saw the ivory-bills fly above the trees, thus avoiding navigation among branches. As with other birds, flight ends with a quick, upward swoop, using the wings to brake. Tanner described ivory-bill flight as noisy, the wings producing a "loud, wooden, fluttering" sound as an ivory-bill took flight and beat its wings strongly, and a "swishing whistle" as one flew past.6 In woodpeckers such as the downy and red-cockaded, wing sound varies with the function of the flight and seems to be an integral part of courtship displays.7 This could also be the case with ivory-bills.
Tanner's descriptions probably best characterize the ivory-bill's flight, but it seems to me that the diverse descriptions of other authors help demonstrate the variability in its flight behavior. Audubon provided us with considerable commentary on the nature of the flight of ivory-bills. . . .
Continues...
Excerpted from In Search of the Ivory-Billed Woodpecker by Jerome Jackson Copyright © 2006 by Jerome Jackson. Excerpted by permission.
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
Excerpts are provided by Dial-A-Book Inc. solely for the personal use of visitors to this web site.
