Rory Wilson’s passion for penguins was born in 1962 when, as a four-year-old, he visited the zoo with his mother. Entranced, he watched as the black-and-white birds vanished below the surface of their murky pool, and bobbed up seconds later, many metres away. The submarine antics that so delighted the young boy would frustrate his efforts many years later to study his favourite birds in the wild. Armed with a master’s degree in zoology from Oxford in the early 1980s, Wilson headed to the University of Cape Town to begin a Ph.D. study of the behavioural ecology of the African penguin (Spheniscus demersus). Africa’s only endemic penguin was in rapid decline from a population of almost two million a century ago to only 220,000 in 1982 (and 180,000 today). The species is currently classified by the World Conservation Union (IUCN) as 'vulnerable to extinction’.
Standing on the shore of Marcus Island off the South African coast on the first day of his field studies, Wilson watched the birds waddle into the sea to hunt small fish in the frigid, foggy waters of the Benguela Current. Dismay suddenly tempered his delight at the prospect of spending several years in the company of his favourite birds. How was he going to observe the behaviour of a species that spends much of its day submerged in the sea? His own seasickness and the amount of time the penguins spend under water soon convinced Wilson of the futility of trying to follow them in a small boat.
Wilson knew that his research could not advance unless he found a way to observe the bird under water. Lacking sophisticated tracking equipment, he created a simple, ingenious device to record, for the first time, how fast penguins swim. It comprised a harmless pellet of radioactive phosphorus embedded in a polystyrene bung and attached to a spring inside the barrel of a syringe. The bung moved as the water pressure varied with the penguin’s swimming speed, creating a pattern of light and dark bands on a radiation-sensitive film strip stuck on the tube. Wilson’s “penguin speedometer”, which was attached to the animal’s breast with a small leather harness, cost him less than a dollar and allowed him to analyse the bird’s swimming patterns.
A Life of Inventions
This basic invention 25 years ago sparked an entire career as a researcher and inventor of innovative devices for monitoring wild animals. Now aged 49, Wilson, who is professor of aquatic biology at the Institute of Environmental Sustainability at the University of Wales, has invented 24 novel devices or techniques which have enabled him and other scientists to study wild animals and to record their natural behaviour in new ways. The devices, three of which are sold commercially, can be used for studies lasting only hours or up to a year. Because they use little battery power and their data are stored on board, there is no need for bulky satellite- or radio-telemetry devices to be attached to the animals. His lightweight, miniaturized loggers cause minimal restrictions to animals’ movements and behaviour.
Since the 1980s, huge advances in the electronics industry have helped many, not least Rory Wilson, produce a wide variety of small loggers. But ironically, as Wilson points out, this is complicating the monitoring of animal behaviour. "There are now devices that sense a plethora of things: speed, acoustics, heart rate, heat loss, feeding, diving, and so on," Wilson says. "All this tends to drive biologists to search out a particular system to answer highly specific questions related to their own select species. Given the enormous numbers of animals in need of study in the world, we need to be consolidating powerful, cross-species logger systems, not all diversifying into our own tiny species corners." Wilson adds that, according to the 2006 IUCN Red List, one in eight bird species and one in four mammals are classified as endangered.
Search for a Single System
Rory Wilson believes that the greatest need is for a single system that will determine the behaviour, energy expenditure and location of animals of many different species. Although Wilson’s solution is technically complex, it is so simple in concept that he calls it his “silly idea”, comparing it to having animals "keep a diary: an automatic diary that measures and records acceleration and heading". Until recently he had insufficient funds to work on this device. Reviewers from funding institutions rejected his grant applications because they fell into unfamiliar terrain between biology and physics, or lacked specific hypotheses about the species on which he wanted to test the logger. His Rolex Award provided the support needed to develop and test his revolutionary invention.
Wilson likens the logger, which weighs only 30 to 48 grams, to the black-box flight recorder that monitors changes in an aircraft’s speed, altitude and heading. It contains a triaxial accelerometer, a tiny electronic device that monitors changes in an animal’s acceleration. For example, a bounding kangaroo may be moving forwards, up/down, and sideways simultaneously. The accelerometer measures along all three axes up to 32 times a second, and, combined with a compass, the device determines the animal’s speed, direction and position. Wilson’s black box can do many things that widely used GPS (Global Positioning System) transceivers cannot, such as functioning in a dense forest, underground or in the ocean.
‘Black Box’ for Measuring Energy
All animals expend energy staying warm, digesting food, and maintaining other vital body functions like breathing and pumping blood — but movement requires energy expenditure ten times higher. "An animal that’s not expending energy is dead," Wilson says. Animals burn glucose to generate energy, consuming oxygen in the process, so by measuring an animal’s oxygen intake in a sealed chamber called a respirometer, scientists can estimate how much energy it consumes just staying alive and warm, and how much it requires while walking, running or swimming. Wilson and his colleagues have already used the logger to record energy expenditure in wild cormorants, and were thrilled when their data corresponded to the figure predicted from trials determining the average oxygen consumption of five great cormorants tested in a respirometer. Zoologists will be able to use Wilson’s black-box to estimate the energy an animal expends flying, swimming, hunting, digging, feeding, fighting or mating. Adding these figures to the baseline energy needed to stay alive and warm will yield a reliable estimate of the species’ total energy expenditure.
This information will have revolutionary consequences. By measuring the energy content of a species’ natural diet, zoologists will know how much time a carnivore must spend hunting, or how long a herbivore must graze, to keep up its strength, grow and successfully reproduce — the ultimate aim of the game of life. "A successful animal," says Wilson, "is one that takes in a lot more energy than it expends. Many conservation issues involve animals that are expending too much energy. Energy for an animal is like money for a human, but if an animal overdraws its budget, it dies. We haven’t had a way of measuring energy expenditure in wild animals before." Data about animals’ energy expenditure will help conservationists understand what constitutes poor, average or optimum habitat, or what minimum area is required for a natural reserve to sustain a viable population of each species. The logger could help resolve important conservation questions, such as whether climate change, predation or over-fishing in its hunting grounds is responsible for the decline of the African penguins.
Invaluable Access to the Wild
Wilson and fellow zoologists are testing the black box on species in Argentina, including imperial cormorants and armadillos. The device has already been trialled on beavers in Norway and the badgers of Wytham Woods in Oxfordshire, England. And closer to home, Wilson has done extensive tests of his logger on the family pet, a Border collie named Moon.
The importance of Wilson's device is exemplified by the insights that will be gained on the Oxfordshire badgers, which are of interest to those studying the evolution of social behaviour. David Macdonald, of Oxford University’s Wildlife Conservation Research Unit, has been observing these badgers since the 1970s, making them amongst the world’s most intensively studied carnivores, but he has always had difficulty tracking their detailed movements at night and observing their behaviour underground. "Key to the issue," he says, "is the detail of where the badgers forage and where they scent mark, and Rory Wilson’s amazing invention will reveal both." Professor Macdonald adds: "This information will not only help us understand the evolution of the badgers’ mysterious social life, but will also be relevant to public health officials who need to understand their role in the transmission of bovine tuberculosis in cattle. The data we will gather in collaboration with Rory Wilson will therefore be not only interesting, but also practically useful."
Revolution for conservation
Wilson hopes his device will unlock many of the secrets of animal behaviour. Not only will it help save animals facing extinction now, it will also provide valuable data on many species almost certain to be threatened in the future. The beneficiaries of his project are, he says, "the unthinkable number of animals that need to be properly understood now, tomorrow and in 20 years’ time."
Published in 2006