Like most people who dedicate a lot of time to study nesting Peregrine Falcons Falco peregrinus, I have treated Derek Ratcliffe’s monograph The Peregrine Falcon (Poyser 1980 and 1993) as the closest thing I have to the Bible. Apart from being beautifully written, it sets out all that was known about the Peregrine at that time.
So, what would Derek Ratcliffe make of this book? I think he’d be amazed at the amount of information that has been gathered in the last 30 years. The level of scrutiny that our Peregrines are subjected to today is incredible. Not only do we have CCTV, but we have satellite tags and, in due course, we’ll have widely available used of DNA, too.
The book starts with an assessment of the falcons as a group, moving on to a chapter on the Peregrine as a species. This provides a succinct summary of what most readers want to know, but much of it is repeated and expanded on in later chapters. I was particularly interested in the detailed treatment of the various Peregrine races around the world.
A substantial chapter is devoted to flight characteristics. This aspect is a personal interest of Richard Sale, and for the Peregrine it represents the major part of its hunting strategy. Sale looks at every aspect of how Peregrines are designed to be outstanding predators, but he also manages to pour cold water on one of its main claims to fame. Ask any nature-obsessed child and they will tell you that the Peregrine is the fastest flying bird. This is based on a series of monitored flights in 1999, when a tame Peregrine was recorded diving at 242 mph, having been released from a small plane at 17,000 feet. Sale points out that at such a high altitude the air pressure on the falcon would be much less compared to normal hunting altitudes of a few hundred feet. Peregrines are fast – but at sea level they are nowhere near as fast.
A huge chapter of 83 pages discusses diet and how this varies around the world. This is an immense amount of data, but well presented with graphics to back it up. Here we also learn about hunting techniques and how the Peregrine positions itself for a successful attack. There is still much to learn about how Peregrines weigh up the costs and benefits of hunting and we are reminded that a lot of what we already know comes from studies with captive birds.
There are two chapters on breeding, and most of this information was drawn together by Steve Watson, who in his own right has worked extensively on Peregrines in Gloucestershire. Every aspect of breeding is considered and I was impressed by how much information has been gleaned from work around the world. I am familiar with much of the UK work and personally monitor 25 nest sites in Hampshire, but here is the data from people doing exactly the same in Europe, North America and parts of Asia.
Movements are discussed and, while I am used to seeing the occasional Scandinavian Peregrine on my patch, I was stunned by the photo of 17 migrating Peregrines perched on a ship moored in the Gulf of Mexico.
Peregrines are supreme predators but nothing had prepared me for the photo of an Eagle Owl Bubo bubofeeding on a Peregrine corpse! It was a reminder that few species are without their own predators, and that with its superior eyesight, the owl can easily pluck an incubating Peregrine off its nest in the dark. A chapter on population explores the growth of Peregrines around the world in the last 50 years. Here the horrors of eggshell thinning are described along with the subsequent recovery following the withdrawal of certain pesticides.
In addition to the text, I was really impressed by the number of outstanding colour photographs. Around 200 images from 20 countries show most of the Peregrine races, providing an amazing resource. In addition, a bibliography of around 1,000 references covers material right up to 2022.
So, what about Ratcliffe… will it still be my Bible? For sure it will be – for its traditional values of fieldwork in the cold and wet after walking miles to view a nest; but when I want to know what’s new in the world of Peregrine research, Sale and Watson will be the book I turn to.