Graham Martin - Bird Senses: How and What Birds See, Hear, Smell, Taste and Feel

BIRD SENSES

How and What Birds See, Hear, Smell, Taste, and Feel

GRAHAM R. MARTIN

PELAGIC PUBLISHING

Published by Pelagic Publishing
PO Box 874
Exeter
EX3 9BR
UK

www.pelagicpublishing.com

Bird Senses: How and What Birds See, Hear, Smell, Taste, and Feel

ISBN 978-1-78427-216-6 Paperback

ISBN 978-1-78427-217-3 ePub

ISBN 978-1-78427-218-0 PDF

Graham R. Martin 2020

The moral rights of the author have been asserted.

All rights reserved. Apart from short excerpts for use in research or for reviews, no part of this document may be printed or reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, now known or hereafter invented or otherwise without prior permission from the publisher.

A CIP record for this book is available from the British Library

Cover: Great Grey owl (Strix nebulosa) taking off from the ground, Finland, April. Danny Green/naturepl.com

For Amber, Bryher, Josie, and Ted

This books aim is to take the reader deep into the world of birds. We may think we know the world of birds through our own senses. But we are just one species, and we are not birds! To get into the world of birds we must go beyond the habitat or ecological points of view. It is necessary also to take a sensory perspective. It is a perspective that leads to an understanding of the different kinds of information that birds have available to them as they live out their lives beside us.

This is a through birds eyes approach to ornithology but as we shall see there is a lot more to a birds world than the information that it receives from its visual system. Other sensory information is constantly in play and interacting to provide each species with a unique suite of information that guides its daily activities. As the book dives deeper into the senses of birds and their diversity across species, we become aware that our world, the human world, is just one way of extracting information from the environment that surrounds us. What we consider to be reality is but one of many worlds in which species live as they rub alongside each other.

As in all aspects of bird physiology, behaviour, and ecology, diversity is the name of the game. The senses of each bird, and the information that they provide, have been uniquely tuned through natural selection to solve the challenges of different environments, the challenges of different foraging techniques, and the exploitation of different resources. Of course there are commonalities across species, but wherever we look there are differences.

While we may ponder the intriguing diversity of birds bills and describe how they are tools for exploiting different resources in optimal ways, it is easy to overlook that those tools need guidance. In each bird species, the senses have become tuned to provide optimal information that guides behaviour, day in, day out.

The book first sets out some basic information about each of the main senses. However, from the start, questions are asked about how senses can and do differ between species. This should help the reader to get a grasp of how to compare and investigate different senses in different species, and to form questions about what information different species might have available from moment to moment to guide their behaviour. What is known about each of the main sensory systems of birds is uneven; some species or sensory systems are known about in detail, others less so. Of course, with almost 11,000 species of birds to investigate, it is not surprising that very little is known about many of them. But that is true of all aspects of their ecology, behaviour, and physiology. We have to piece together general truths from patchy information.

The later chapters bring together what is known across different species, to offer explanations of how birds cope with particular environmental challenges. I have focused particularly on activity at night and activity underwater, both of which provide very different challenges to what we may think of as birds normal daytime terrestrial environments. In dwelling on these topics, it is perhaps surprising to discover how often birds are prepared to act guided only by sketchy information, as they operate at the limits of their sensory systems.

Finally, there is discussion of the many sensory challenges that birds face because of the obstacles that humans have contrived to put in their way, from power lines to windowpanes. A sensory ecology approach does suggest some answers to those challenges, and so the book ends on an optimistic note. It shows how understanding the senses of birds, and the information that they provide, can suggest solutions to the problems that humans have presented them with.

My aim has been to make technical information understandable and the book readable for the keen birdwatcher and naturalist, as well as the more specialist reader. I have brought together a wealth of diverse information, but the book is not laden with references. Some of the more difficult topics are explained in boxes that can be referred to separately from the rest of the text. However, the reader can be assured that all statements are well supported by published material. There are suggestions for further reading which can be followed up should the reader be intrigued to dive deeper into the sensory worlds of birds.

Graham Martin

Emeritus Professor of Avian Sensory Science

University of Birmingham, UK

October 2019

The taxonomy and naming of birds is a matter of much debate. There are rival taxonomies and there can be heated debates. Furthermore, taxonomic revisions are frequent, especially now that classification based on genetic data is firmly established. The taxonomy, scientific and English names used in this book follow those of the International Ornithology Congress World Bird List (www.worldbirdnames.org). This is a freely open resource, with a lot of useful information, lists and spreadsheets, that can be downloaded. It is frequently updated. Names used in this book are based on version 9.2 (doi: 10.14344/IOC.ML.9.2) but by the time you read this book it is likely that a newer version will be available from the IOC.

I have studied the sensory world of birds for a lifetime and have worked alongside a wonderful range of keen and enthusiastic people. They have helped me to investigate a fantastic range of birds and their senses, and in many different locations. I thank them all for their support, and the exchange of ideas and enthusiasm. The names of them will have appeared as joint authors of papers or in the acknowledgement footnotes of papers. They have all contributed to this book in different ways, and I acknowledge their help and encouragement. Various colleagues have read parts of this book, but one person who has read it all and sorted out over-complicated language and many grammatical errors is Judith Burl, and I especially thank her for helping to bring the book to completion. I must also acknowledge the very skilful and helpful copy-editing of Hugh Brazier. With an eagles eye he caught my errors and checked many details. He gave the manuscript a deep clean and final polish. Finally, I thank people who over the years have attended talks that I have given to both specialist and lay audiences. They have asked intriguing questions and challenged me to explain more. In so doing they convinced me that there could be a readership for a book on this topic.