New book hones in on animal performance

How animals function in their natural habitat and how evolution has shaped this function are the focus of a new book written by biologists at the University of California, Riverside and the University of Massachusetts Amherst.

In explaining animal performance, "Animal Athletes" (Oxford University Press, 2016) provides an integrative overview of the ecology and evolution of animal athletics, and covers a range of fields, including physiology, biomechanics, functional morphology, and genetics.

To eat and not be eaten

All animals are athletes. But humans only tend to pay this fact any attention in sporting events, where the goal is to win. For non-human animals, however, the goal of life is the win, but winning is surviving. To survive, animals must out-compete their rivals, and perform better than their dinner.

"From their perspective, animals must also outperform those who perceive them as dinner," said Timothy Higham, an associate professor of biology at UC Riverside, who wrote the book along with Duncan J. Irschick, a professor of biology at UMass Amherst. "This continual challenge has shaped how animal athletes have evolved. For example, catching a gazelle comes with many challenges. Gazelles are fast, and they have an incredible ability to maneuver. Cheetahs must therefore exhibit high sprinting speeds and an uncanny ability to turn on a dime. If they maximize their performance in these ways, the cheetahs can successfully eat."

Higham explained that animal survival boils down to capturing food, avoiding predation, finding mates, and defending territories—all of which are often based on performance. He noted that these behaviors, however, do not necessarily involve the same measures of performance.

"For example, jumping performance might be important for evading a predator, whereas bite performance might be important for capturing prey," he said. "A high-performance display might be critical for attracting mates. Thus, one cannot understand how an animal can do something without knowing why it's doing what it's doing. This requires an understanding of ecology. Over time, natural or sexual selection can place pressures on performance, which will then trickle down to morphology. Evolution, however, can only work within certain boundaries, or constraints, related to the history of a certain lineage as well as physical constraints. Thus, it's important to consider evolution, ecology, and performance collectively rather than in isolation."

In our dreams

Non-human animals can often do things that humans could never dream of doing: flying high above the mountains, swimming in the deep ocean, gliding through the forest, or sticking to inverted glass surfaces.

"Understanding extreme performance will enable us to understand how animals might function as environments change and potentially become more extreme," Higham said.

Examples of extreme performance from the book include elephant seals diving up to 1,500 meters below the surface, peregrine falcons streaking through the air at speeds up to 350 kilometers per hour, and tiny snapping mantis shrimp accelerating striking appendages at accelerations exceeding 100 kilometers per second squared.

"We can only dream of exhibiting these extreme levels of performance," Higham said.

When passion turns to ink

The 272-page book resulted from a passion Higham and Irschick share for understanding how animals function in their natural habitat. Both scientists combine evolution, ecology, and biomechanics in their research.

"Our goal for writing this book is to inspire young scientists, but also give our perspective on biological function to a broad audience of professional biologists," said Higham whose research focuses on understanding how animals work and why they work in the way they do. "We are aiming this at a wide audience, with the hopes that our perspective will be contagious. This is especially relevant for undergraduates, graduate students, and faculty that are interested in this general topic. That said, this book will also be accessible to keen members of the public."

One motivation for the authors to write a book like "Animal Athletes" now is that today technology is giving scientists like them the capacity to study the intricate details of animal function.

"We are quickly gaining the capacity to track and measure animals during natural behaviors in the wild," Higham said. "We can place miniature cameras and biomechanical devices on small birds as they fly through the sky, which gives us an animal's perspective on things. Similarly, we can thank engineers for developing smaller and smaller wireless devices for measuring acceleration, muscle activity, temperature, and GPS coordinates in real time. These devices, which include onboard memory and a battery, can often dip below a few grams. This means that nature is becoming the new lab, and we have an increasing ability to quantify everything an animal does at a very fine time scale."

Provided by University of California - Riverside