In conversation with Tim Birkhead and Bernie Zonfrillo - Birds and Us: A 12,000 Year History from Cave Art to Conservation
Bernie: Earlier this year you published Birds and Us looking at the fascinating relationships between birds and people over time. What made you decide to write a book on this topic?
Tim: As well as being interested in scientific aspects of birds, and in particular, their promiscuity, I have also been intrigued by how we know what we know about birds. That is, I am interested in where our knowledge of birds has come from. Of course, all our knowledge has come from people’s interactions with birds, whether they are scientists or birdwatchers, falconers, hunters, bird keepers and so on. In fact, I have been especially interested in how people outside science have contributed to our understanding of birds. That’s what this book is about.
As a boy, I had an aviary in the garden and kept a range of species as pets. That allowed me to get close to birds, closer very often than in the wild. It also gave me valuable experience in rearing birds in captivity that would later play such a crucial role in unravelling the consequences of female birds mating with more than a single male.
Bernie: In Chapter 2 you discuss how the Ancient Egyptians used herons as decoys when hunting. That came as something of a surprise to me and I wondered whether you had ever tried it, and whether it works?
Tim: It came as a surprise to me too. It must have worked since it is a common theme in Egyptian tomb paintings: a heron standing (presumably tethered) on the prow of a boat pushing through the papyrus swamps. The same technique was still being used hundreds of years later in Europe. Bird trappers have often used decoys, either live birds in cages, or tethered, or dead birds. People shooting Woodpigeons today often use plastic decoys to lure the wild birds within shooting range. People catching wild finches, as they still do in Malta, often have caged decoy birds. Decoy birds work because either the sight and/or sound of the decoys are irresistible to their wild counterparts. That tells us something about the cues that wild birds use to find suitable habitat or feeding areas.
I haven’t tried using a decoy heron, although I’d like to. I would be optimistic about it working since, as you may remember, John Krebs conducted a study of Great Blue Herons (very similar to our Grey Heron) in the 1970s, to test the so-called ‘information centre hypothesis’ for why birds roost together. He used model herons, and wild herons were attracted to them and alighted amongst the model herons.
Bernie: You also write about the millions of sacred ibises mummified by the Egyptians. What was that all about?
Tim: Using herons as decoys was an entirely utilitarian way of getting birds for the pot. The relationship the Egyptians had with ibises, however, was spiritual. For them the ibis was sacred. The ibis represented the god Thoth — the god of wisdom and of writing. Its long, dark-tipped beak was thought to resemble a writing quill. People presented mummified ibises, or even just parts of ibises, such as feathers, to a priest as a votive offering. It was probably like throwing coins into a well and making a wish. Because of their ability to fly, birds like ibises, but also falcons, were seen as messengers between this world and the next. Buying a mummified ibis as your offering, your wish was more likely to come true. In this case that wish was probably for an easy transition between this life to the next. Obsessed with the afterlife, the Egyptians, of course, perfected the mummification of human bodies for the same purpose — to make it to the next world.
Egyptian falcon jewellery © Tim Birkhead
Bernie: In Chapter 3 you discuss both Aristotle and Pliny. Wasn’t one of them said to be killed when a Lammergeier dropped a tortoise that landed on his head? This sounds a bit weird, but Lammergeiers do drop bones from a great height to crack them to get access to the marrow.
Tim: Ha! It was neither Aristotle nor Pliny, but the Greek tragic playwright Aeschylus who was said to have died when a tortoise, dropped by an eagle, landed on his head. In Africa, various large eagles and the Bearded Vulture are known to prey on tortoises that they kill by dropping them from a great height. So, poor Aeschylus was just unlucky.
Bernie: Chapter 4 is concerned with falconry. It is amazing how in the past raptors were prized for their falconry exploits, but subsequently landowners have, in some cases, persecuted these birds to almost to extinction.
Tim: Yes, this is an intriguing contradiction. It is remarkable that falconry was such an important symbol of status and persisted for so long. I suspect that in the future people may look back in similar disbelief at our enduring obsession with another status symbol: the car.
Falconry went into decline after guns were invented; guns made killing other birds and mammals like rabbits for food, so much easier. Then, once wealthy landowners started in Victorian times to rear grouse in large numbers to shoot, they were in direct competition with birds of prey. The Hen Harrier comes to mind — persecuted today to the brink of extinction in the UK. The other remarkable thing about falconry and other forms of hunting is the deep-rooted obsession among its perpetrators in killing things merely for fun. I find that very depressing. As I discuss in the book, at least falconry was (and still is) more civilised in that it usually resulted in a kill and doesn’t leave the countryside littered with dying prey.
Hooded falcon © Tim Birkhead
A major theme in the book is the switch from a callous and brutish attitude towards birds, to a more empathetic approach. We tend to think of this change as relatively recent. However, as long ago as the Middle Ages, people (often women) warned about the brutalising effect hunting and falconry had on those who practised it. They were less worried about the cruelty the prey experienced.
Bernie: In Chapter 5 you look at the tongues of woodpeckers and wrynecks, and at Leonardo da Vinci’s fascination with the tongues of these birds. I have skinned a few woodpeckers and one Eurasian Wryneck (that died on hitting a window in Glasgow!) I was able to see how the long tongues and anatomical skull adaptations worked. Ornithologists these days seem not to be interested in such matters. The British Museum of Natural History used to sell a booklet on how to skin birds and that set me off collecting just about anything from Goldcrest to Golden Eagle!
Tim: That’s very interesting. I was fascinated to discover that Leonardo left himself the Medieval equivalent of a post-it note, reminding him to dissect a woodpecker’s tongue. Leonardi was an engineer and loved to see how things worked. If you have ever seen the extended tongue of a woodpecker or a wryneck, you do wonder where it all goes inside their mouth. The answer is extraordinary. An American friend of mine once had a tame acorn woodpecker that would extend its very long tongue for him (and me). It was one of the most remarkable things I have ever seen.
You are right, many of today’s birders are reluctant to look at such things. That’s one reason why I wrote about the woodpecker in Birds and Us. Like you, Bernie, I have always been keen to examine any dead bird I come across. I managed to turn this habit into something extremely constructive during my studies of promiscuity. Who wins in the promiscuity game depends on both the quantity and quality the sperm that males produce. How does one study this? The answer is by picking up birds killed on the road. Over a period of some twenty years, I obtained a large number of specimens and what emerged was a clear pattern. Those birds that we knew from DNA paternity studies were very promiscuous, typically had large testes that produced huge numbers of very sleek, long sperm.
Bernie: You have spent many years studying guillemots, how has that shaped your appreciation of birds?
Tim with colour ringed Guillemot on Skomer © K. Nigge
Tim: I started studying Guillemots in 1972 and never stopped. The goal of my PhD was to understand why Guillemot numbers were declining in the southern parts of their range. Guillemots are long-lived, some our colour-ringed birds are approaching forty, so a three PhD was insufficient to understand their population dynamics. We do now, at least for Skomer Island where I work. The focus of that project now is on conservation, specifically how seabirds biologists should monitor numbers and breeding parameters in an accurate and reliable way. Monitoring is almost a dirty word in ornithology and is regarded as the lowest form of scientific endeavour. As consequence monitoring has often been delegated to untrained (but often highly committed) assistants. The appearance of avian flu has cast new light the value of monitoring and the need for well-trained, well supervised assistants who results accurately reflect changes in numbers of population biology, such as the timing of breeding or breeding success.
My studies of guillemots on Skomer have spanned both population biology and behaviour, and in terms of behaviour, Guillemots are extraordinary. Watching a colony of Guillemots is like watching (I presume) an episode of EastEnders.
Birds and Us book © Tim Birkhead
Tim Birkhead FRS is emeritus professor of behaviour and evolution at the University of Sheffield. His research on promiscuity and sperm competition in birds re-shaped our understanding of bird mating systems. He is committed to the public understanding of science as has written several popular science books, including Promiscuity (2000), The Wisdom of Birds (2008), Bird Sense (2012) The Most Perfect Thing: the Inside (and Outside) of a Birds’ Egg (2016) and Birds and Us (2022). His children’s book What it’s like to be a Bird (2022) illustrated by Catherine Rayner, won the English Association’s Margaret Mallett Award in May 2022. His latest book is available to purchase from Waterston House, SOC Headquarters.
Bernie Zonfrillo is an Honorary Lecturer (School of Biodiversity, One Health & Veterinary Medicine) at the University of Glasgow.