In this book Tim Birkhead has unscrambled the complexities of the biology of eggs with writing as smooth and rounded as an eggshell.
As I sit writing this review I am listening to a dawn chorus dominated by Blackbird song, and I am thinking of the female Blackbird who is sitting on a nest containing four eggs in the ivy on the wall by the shed in my back garden.
The more you ponder those eggs, the more amazing they seem. They are the perfect mixture of the beautiful and functional: they look good and they do the job very well. ‘My’ female blackbird can sit on those eggs most of the day and keep them safe and warm, but she can also nip off to feed unencumbered by them. She and her mate can choose where exactly to build their nest so that it is in a convenient but safe position. The developing eggs are separated from the outside world by a hard protective shell but one which allows water vapour and other gases to escape through it. This Blackbird nest is well hidden in thick ivy but for other species the eggshell can be coloured and patterned for crypsis as the eggs sit in the open.
As a former evolutionary biologist myself, I can easily get taken away by thoughts of ‘Why is it like that?’ about the functional significance of animal behavior and ecology and there are plenty of explanations of that sort in this book, for example, ‘Why are eggs egg-shaped?’. But there are some pretty intriguing ‘How?’ questions about eggs too: ‘How is an egg laid?’, ‘How is the hard shell produced?’, ‘How does an egg survive attacks by bugs and microbes?’ etc etc. This book is full of clear explanations of those first few weeks of any bird’s life, from fertilisation to hatching. And it’s fascinating. Here you will find the answers to questions that have passed through your mind already, but even more explanations of things that you didn’t know about but are equally intriguing. I found the whole story of how eggs repel microbial attack fascinating.
Just in case you might still be thinking ‘A whole book about that?’ then I should tell you that the writing is wonderfully clear and there are lots of stories about the author’s research and experiences, and insights into past characters who have pillaged or studied birds’ eggs. This is a very good example of science writing that is factually accurate but also a jolly good read.
The Most Perfect Thing: inside (and outside) a bird’s egg by Tim Birkhead is published by Bloomsbury.