Indiana Jones is a wildly popular daring-do movie-matinee adventurer, known to millions, but Joel Berger of the University of Montana and the Wildlife Conservation Society is perhaps braver (and crazier) , but very real, and ought to be better known by biomedical and life science librarians and their readers.
In his book, The Better to Eat You With: Fear in the Animal World (The University of Chicago Press, 2008. ISBN: 13: 9878-0-226-04363-0), uses exceptional ingenuity to find scenarios and develop tactics to test hypotheses about how prey animals, most commonly moose, elk, and buffalos come to fear and flee from (and occasionally to fight with) predators: mostly wolves, but also grizzly and black bears, and the occasional mountain lion, Siberian tiger or snow leopard.
Interviewing is pretty much out, the fictional Bullwinkle’s talkativeness aside, so observation is pretty much the only way to figure it out, but it is the behavioral and environmental manipulations that Berger uses that helps him create something like a laboratory of experimental animal psychology wherever he goes.
Here are some of the situations he explores in his book.
How can you tell when a prey animal is concerned about an approaching predator? What are good measurable indicators of initial predator awareness? Watchful waiting? Intention to flee?
If you have had a cat, you might have guessed that pilo- erection (the hair-raising of many mammals when being threatened or threatening others) is certainly one clue, but is it quantifiable? And at what distance does such an observation become unreliable?
Berger suggests that the time for some animals, particularly large hoofed game, the which point the animal interrupts its browsing, and the duration of the interruption, and any repeated sequences of the interruptions, are things that can be not only counted but timed to develop data points.
Prey animals that interrupt sooner, interrupt longer, and interrupt more often, have probably learned to be more wary, or were given a genetic endowment that favors wariness. He even offers a scenario how this might be tested, and the issue of learning to fear versus inherited fear.
For this test, we need (and Berger finds) three populations of moose, for example.
1. Those prey animals who have lived with wolves or bear or cougars around all their lives (e.g. moose in parts of the Canadian wilderness where predators were not extirpated). They should be the measurably the wariest, although sorting out whether or not learning or heredity is dominant would still be difficult.
2. Those prey animals that live in areas where there have never been predators, for example, those who live on remote islands that never had predators. They should be measurably the least wary, although if they are unexpectedly very wary, a score in favor of inherited fear might be better made.
3. Those prey animals who live in an area where predators are being re-introduced after an absence of many generations of prey animals. If the prey are very wary, right from the start of the reintroduction, such fear is unlikely to be a learned behavior. It is likely to be inherited instinct. But , if the animals are initially clueless, and suffer great losses to predation, but then learn to cope by being wary, fleeing sooner, or getting more combative, then we might say that fear is learnable and learned.
In numerous studies detailed colorfully in the book, Berger tends to come down on the side of fear being primarily learned.
He bases this on the early experiences of naïve prey in national parks where wolves are re-introduced. Large mother moose who could flee with their calves or fight on behalf of their calves, often lose a calf on their first encounter ever with a predator.
But the lesson is often learned by next calving season. Prey are by no means uneducable. In fact, in cases where their prey is more social (elk are gregarious more often than moose and apparently can learn from observation or some form of communication) it appears that learning to be wary and flee sooner can somehow be transmitted to elk mothers who have not personally lost calves.
Seeing a wolf or a bear or a cougar attack a prey animal is not always a practical way to judge alertness and fear responses, quite possibly because you cannot count on either predator or prey showing up exactly at the same time, whenever you are ready to observe them.
So Berger develops a number of proxy situations. He asks himself: Will moose in areas that have long had abundant predators predictably react more quickly to a recording of a wolf howl, than will totally naïve moose? (The answer is dramatically YES….for naïve moose often do not react at all). But will the time to demonstrate an alert response also be shown to decrease in animals that used to be naïve, but have had a new if sad experience with predators? (The answer is also yes.) This last suggest learning once again.
A trick question might be if it is just the noise that matters. But it turns out that recording of loud howler monkeys does not get much of a rise, despite equal blaring.
One surprise, however, is that the roar of the African lion uniformly causes an alert state of fear even in animals which have never seen a lion in a thousand years or recent history. Berger suggests that this anomaly is perhaps best explained by the fact that some fear responses are genetically preserved, perhaps because they were uniformly lethal for those who did not inherit that particular type of fearfulness.
Berger points out the fact that throughout pre-historic North America, a variety of giant lion-like predators, much larger than mountain lions, and presumably with vocalizations similar to the African lion, were clearly present. This can be seen from fossil findings, from the retrieval of bones from site like the LaBrea tar pits, and from human-made cave paintings or other artifacts.
In one of his most interesting speculations, he suggests that the timing of the of Asiatic migration to North America might have been influenced by more than just the periods at which a land bridge existed or water-craft were invented.
He suggests it might have been held up until those Asiatic hunter peoples developed their own fear-and-experience-based ways of fending off predators in order for themselves to become predators on the large animal prey of the time (e.g. mammoths) more plentiful in the New World.
Berger also demonstrate that there is some evidence that prey animals can associate, and react with fear, to the sounds of scavengers (like ravens or eagles or vultures) with the presence of the predators that initially killed the prey. In other words, some of them realize and internalized the notion that the Lords of Leftovers had to be preceded by the Princes of the Prime cuts. If the one were around, the other could not be far away.
Of course, there are other pungent parts of the book, such as Berger’s expertise in tossing snowballs of lion’s urine or bear crap in order to detect if olfactory cues also factor into different levels of awareness.
Do naïve prey ignore or dismiss odiferous signs of imminent danger (pretty much); do those raised constantly with predators respond more reliably and appropriately (yup!), and can a change in sensory awareness and signal processing be observed in animals transitioning to a new world that now includes predators? (it seems so.)
All along the way, are other interesting nuggets of animal behavior information, including the role of the influence of leaders.
For example, there are pods where it appears that the lead whale learns to pick fish off of commercial fishing lines, and the rest of the group learns from him. However, when the lead whale dies, the pod simply forgets this new skill.
And clearly there are differences of intelligence and personality even among animals within the same species and pack.
For example, leading life sciences librarians with an interest in animal learning and the transmission of fear and flight behaviors, and a few bucks, will demonstrate their superior intelligence by getting this book as soon as they sense its importance!
The others, well, they may could fall prey to critical faculty customers who want to know why this valuable resouce was not already in place.
Tony Stankus tstankus@uark.edu Life Sciences Librarian & Professor
University of Arkansas Libraries MUULN 223 E
365 North McIlroy Avenue
Fayetteville AR 72701-4002
Voice: 479-575-0021
Fax: 479-575-4592
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