In 1938, the London publisher Country Life published the Animal Language sound book which featured text by Julian Huxley (1887–1975), a pair of audio records produced by Ludwig (Karl) Koch (1881–1974) and photographs by Ylla (1911–1955). The book was dedicated to the different sounds made by the animals at London Zoo and Whipsnade Zoo in Bedfordshire, including camels, wolves and seals. Ludwig Koch provided the impetus for the book: “Mr. Koch, to whom the idea of this book is due, is a real enthusiast in this branch of work.” (Huxley/Koch 1938, 1) Before his emigration, Koch had invented the “Tönende Buch” together with Lutz Heck, the director of the Berlin Zoological Garden: Schrei der Steppe was published by Knorr & Hirth in 1933, followed by Der Wald erschallt in 1934. For both books, Ludwig Koch provided sound recordings made with a phonograph, a selection of which were saved on records and included with the books (Fischer/Willkomm 2018). The concept of soundbooks then emigrated with Koch to London.

In the biologist and zoo director Julian Huxley, Koch found an open-minded partner who was always looking for new ways to disseminate knowledge among a wide audience. Huxley’s communication concepts as Secretary of the Zoological Society of London included the establishment of a children’s zoo and artists’ studios within the zoo’s grounds, participation in a BBC radio series, and the publication of several books (Huxley 1974; Kevles 1992). The third originator was the Viennese-born photographer Ylla (actually Camilla Henriette Koffler), who had been running a studio specialising in animal photography in Paris since 1933. In 1937, Ylla published two books with Methuen, the London publishing house: Ylla’s Dog Fancies and Ylla’s Animals. These were followed in 1938 by Big and Little, published by Country Life in London. In the same year, her work appeared in Animal and Zoo Magazine, edited by Julian Huxley. Ylla was therefore a well-known animal photographer in London when the collaboration for Animal Language came about.
Ylla’s photographs in Animal Language show the animals in moments of communication, when they appear to be “speaking”. In individual portraits or sequences of images, she follows their facial expressions and gestures as they produce the animal sounds. Her close-up portraits portray the range of accompanying postures and physical expressions, translating acoustics into a language where sounds become visible.

The book reflects the challenges of phonetic recording, as some animals hardly communicated at all and others communicated only at rare moments and with specific intent: “Not only does one species often produce a great range of different sounds at different times, but many animals seem very chary of letting us hear some of the sounds of which they are capable, or even their most characteristic utterances. […] As with animal photography, however, technique alone is not sufficient: the greatest patience, skill, and determination are needed to make the technique effective.” (Huxley/Koch 1938, 1)
Patience, perseverance and empathy are the necessary basics for both the bio-acoustician and the animal photographer to record animal sounds and photograph animals in their moments of articulation. Ylla's images show a close and immediate encounter with the animals, their expressions and attitudes captured and photographed with the same care the photographer would extend to human models.
Ylla emigrated from Paris to New York in 1940, where she continued her career as an animal photographer. In the USA, she produced books such as They All Saw It (1944), Dogs (1945) and Two Little Bears (1954) among many others. All three volumes were initially published by Harper & Brothers, N.Y., but many of Ylla’s books from the 1940s and 1950s were also translated into several other languages at the same time as they appeared in the USA – an expression of the photographer’s transnational visual language and her international recognition as an animal photographer and children’s book author. In 1950, she collaborated again with Julian Huxley on the children’s book Animals, (Hastings House, N.Y.), for which the biologist provided the text.