Sixteen of the students also participated in a laboratory session, which allows them to fulfill the university's lab-science requirement. Even if Gould simply lectured, he would pass the toughest muster: Peter Boger '01 says Gould is "wonderful -- informative, organized, and interesting." Thanks to Gould's dry humor, the lectures are "almost like a stand-up routine," according to Cara Viglucci '01, "but better, because you're learning at the same time."

Words alone don't tell the tale in EEB 311, however. As Gould points out, "One of the great things about animal behavior is that it's so visual. It lends itself to slides, pictures, movies, tapes. Using a lot of graphics allows me to bring animals into the lectures, even if in a very pale way." Gould enhances his lectures with a wealth of visual material -- mostly digital images he has created or manipulated on the computer and stored in the laptop he brings to lectures. Not many years ago, says Gould, he would have made slides, a process that could take weeks -- "if I was lucky." Now, thanks to electronic scanners that convert photographs to digital images, "if I see something in National Geographic, it can be in the lecture an hour later." [For more on how computers aid teaching by Gould and other professors, see "Viewpoints." ]

Gould says, "I want the students to think about what it's like to be an animal. What are these creatures doing to live, and how has evolution shaped their behavior? What are the relative roles of instinct and learning? Why are primates different, and are they smarter than other animals?

"Pictures make it impossible not to think about these questions. You see a picture of a chimpanzee holding a big stone, apparently about to smash a nut. You have to wonder, 'What's going on between those two ears?'"

In the lecture hall, Gould stands with laptop at the ready, a huge screen behind him. As he lectures, he sends image after image from the computer to Kresge Auditorium's digital projector and then to the screen -- between 50 and 100 images per hour.

Among the images flashing by is a photograph of a male lizard with his bright red dewlap vastly extended -- a mating display intended to attract females. "The bobbing of his head, the way he reveals and conceals the dewlap, varies from species to species," says Gould.

To indicate the importance of sound in mating behavior, he taps the keyboard and up pops a photo of a loudspeaker horn. Its surface is clogged with crickets. Gould explains they are female crickets attracted by the recorded chirping of males, which the speaker is broadcasting. "People think animals are social," he says. "Almost no animals are social, except to find a mate."

The computer projects a clip of a 1937 film made by pioneer Austrian ethologist Konrad Lorenz, demonstrating automatic egg-rolling by geese. "When an egg is placed outside the nest," explains Gould, "the goose rolls the egg back with his beak -- or her beak, as both parents share egg duty." When Lorenz removes the egg completely, the goose continues its rolling motion, as if the egg were still there. "The goose isn't figuring out the best way to roll eggs; it is engaging in a completely automatic behavior that must be carried to completion," he says. "It's good for recovering eggs, but not for demonstrating goose intelligence."

A giant animated honey bee appears on the screen, the movements of its abdomen illustrating the "dance" performed by forager bees to indicate direction and distance from hive to food source. Gould, who has spent much of his life studying bees, believes their dancing constitutes "by far the most elaborate communication system known outside Homo sapiens." Moreover, he says, the dance language has "dialects": the same number of waggles in a bee's dance represents different distances for Egyptian, Italian, and German honey bees.

Charts and graphs also appear on the screen, and, as students watch, Gould enters variables so that curves rise and fall, bars lengthen and shorten, and pie slices wax and wane. "Changing the parameters of a dynamic process is the best way to observe how the factors interact," he says. "My absolute favorite is to play God with age distribution of human populations."

He charts, for example, a population in which "people live to 71 on average, and have two children, starting at age 20." He compares the effect on population growth of living to 55, having three children, but starting at age 18. Or of having two, but starting at age 12.

He likes to compare what he calls "The Princeton Plan" -- having 1.6 children beginning at age 32, "which leads to negative population growth," with the "High School Dropout Plan" -- 3.2 children beginning at age 17, "which results in exponential growth." It becomes clear, he says, "that change of life span has no major long-term effect on population, as long as people aren't dying off before they reproduce."

Some students complain that the images flash by on the screen in overwhelming profusion. For most students, however, the opportunity to see "everything from the innate behaviors of seagulls, to the !Kung bush people, to the mating displays of mountain goats," says Boger, makes up for the breathless pace of lectures. And as nascent ethologist Cristy Lytal '01 observes, "The graphics are effective because vision is a sense that we rely upon very heavily as primates."

"VIRTUAL" LAB EXPERIMENTS

While computer technology enhances Gould's lectures, instructional computing is even more in evidence in the laboratory sessions. Here, Gould uses an interactive computer-based tutorial that allows students to create and test their own hypotheses -- software that in 1996 helped convince the Carnegie Foundation for the Advancement of Teaching to name him New Jersey Teacher of the Year.

To study prey recognition in toads, for example, Gould has created a Cricket Library -- computer animations of crickets, projected on a screen. A real toad placed opposite the screen reacts to the animated crickets moving across it. "What is it that makes one cricket a potential prey item and another not?" asks Gould. "Students play with that, asking 'I wonder if color matters? I wonder if it's the size? Could it be the motion?' Students think about the different kinds of things the toad may or may not respond to, and present the toad with different types of crickets."

"It's not a cookbook lab," says Cassandra Nuñez, an EEB graduate student who leads the labs (another graduate student, Lenny Gannes, is Gould's teaching assistant for the lectures). "We don't tell them what to test, and they don't all test the same thing. They form their own hypotheses, and decide what kinds of test they are going to do."

To test their hypotheses, students can use the Cricket Library and manipulate its images. They can make the cricket green, or red, or brown; static or mobile in several ways; small, medium, or large (there is even an "extra-large" cricket). Does the toad perhaps need to know the cricket is three-dimensional? Students can add an outline, or highlights, and find out.

Lytal, a participant in the lab, believes such software maximizes the effectiveness of necessarily limited experimental time. "Finding a sample of live crickets like these would be difficult at best," she says. "It would also be difficult to control when real crickets entered a toad's visual field and for how long they remained there."

One universal finding, says Gould, is that for the toad to recognize a cricket as prey, the cricket "must be elongate and move horizontally along the axis of its body. If you show the toad a vertical cricket, the toad will actually cower in the corner of its tank." And, not surprisingly, "You have to give the toads a real cricket every so often, or they won't play."

Students then proceed to assess the statistical significance of their results by using another program, Essence of Statistics. The program, which Gould developed for use in a statistics course he teaches, is useful "even with small samples," says Nuñez.

"Sometimes the experiments don't yield good data," Nuñez acknowledges. "The toads are used a lot, they get stressed out, maybe they're not hungry. They may respond actively, or they may lunge only once or twice, or maybe not at all. "But that's part of doing science, too. Not all experiments yield startlingly meaningful results. If something doesn't work, you think, 'Why? What could I do differently?' And if you didn't get the result you expected, often you got some other interesting information."

"What's important in the lab," believes Gould, "is learning to do science -- to formulate hypotheses, and collect and analyze data. If students get the 'right' answer that's fine, too, but we want them to learn how to do science and have fun doing it."

A FAMILY AFFAIR

Gould himself has had fun doing science for many years. In 1967, while a student at the California Institute of Technology, he was drafted into the Army. A tour of duty in Germany changed his life. "The greatest thing the Army did for me," he says, "besides convincing me I never wanted to work for somebody else, was give me a chance to read."

Among his readings was Lorenz's 1952 classic of ethology, King Solomon's Ring: New Light on Animal Ways. "That book convinced me I wanted to study animal behavior," he says. The book is on the EEB 311 reading list, along with Gould's own Ethology: The Mechanisms and Evolution of Behavior (W. W. Norton, 1982).

By the time Gould returned to college, CalTech had added a course in animal behavior. Gould graduated with a B.S. in molecular biology and went on to earn a Ph.D. in animal behavior at Rockefeller University. Since 1975 he has been at Princeton, where he has studied birds, bees, fish, and, he says, "occasionally even people." His long bibliography includes five books on animal behavior coauthored with his wife, Carol Grant Gould -- most recently, Sexual Selection (W. H. Freeman, 1989, 1996) and The Animal Mind (W. H. Freeman, 1994).

Collaboration with family members may be a secret of Gould's pedagogic success. He credits his daughter, Clare, a senior at Princeton Day School, with scanning much of the material he uses. She also edits the scans and creates animations, including those for the Cricket Library. His son, Grant, a junior at MIT, is Gould's collaborator on the presentation software and Essence of Statistics.

Gould is grateful to various sources -- the Pew Charitable Trusts and the university's Council on Science and Technology, 250th Anniversary Fund, and Dean's Fund for Curricular Innovation -- for supporting his efforts to place online the images used in his courses. But most of all he thanks his kids: "I could never do this if I didn't have teenage children. You need someone who says, 'Gee, Dad, wouldn't it be neat if we could...,' and then shows you how to do it."

A frequent contributor to PAW, Caroline Moseley is a writer in the university's Office of Communications.