Tim Birkhead FRS is an author and biologist, emeritus Professor of Behaviour and Evolution at the University of Sheffield, one of Britain's foremost ornithologists, and a leading light in popular science communication. His professional interests span ornithology, evolution and reproductive biology, as well as the history of science. He is known for his work on both the mating systems of birds and the history of ornithology. He has also led one of the world's best-known long-term research projects, studying the biology and population dynamics of Britain's auks and other seabirds.

Elected as a Fellow of the Royal Society in 2004, Tim's awards include the Elliot Coues Medal for outstanding contributions to ornithological research, the Association for the Study of Animal Behaviour medal, the BOU's Godman-Salvin Medal, for distinguished ornithological work, the Zoological Society of London's Silver Medal, and the Stephen Jay Gould Prize.

Tim has written or edited 15 books, including four popular science titles published by Bloomsbury - The Wisdom of Birds (2008), Bird Sense (2012), The Most Perfect Thing (2017) and The Wonderful Mr Willughby (Bloomsbury 2018), with his latest work devoted to the life and afterlife of a true icon of extinction, The Great Auk (2024).

Award-winning author and illustrator, Catherine Rayner, was born in Harrogate and now lives in Edinburgh. She has a BA Hons in Visual Communication adn Illustration from Edinburgh College of Art. Winner of the CILIP Kate Greenaway Medal 2009 for her second book, Harris Finds His Feet, Catherine was also awarded the Best New Illustrator Award at the Booktrust Early Years Award in 2006, for Augustus and His Smile. She regularly exhibits her artwork in galleries all over Scotland, and illustrates her own range of cards.