What Can Scientists Do To make Animals 'Happier'

The rhesus monkey ambles over to the side of its cage and reaches up to a blue metal box strapped to the bars. With a long finger it touches a metal bar protruding from the box. Five touches . . .10 . . .15 - and a small white pellet rolls out into a slot. The monkey fishes out the banana-flavored snack and pops it into its mouth. Then it presses a second metal bar and the voice of Willie Nelson fills the room: "Mamas, don't let your babies grow up to be cowboys. . ." No, this scene at the University of California, San Francisco, is not part of an experiment on the food and musical preferences of primates. Instead, animal behaviorist Hal Markowitz and Joseph Spinelli, director of animal care at UCSF, are tackling a much tougher question: how to keep lab animals contented. Few scientists expect a conclusive answer. But the question is profoundly important to researchers who use primates in their research. The reason: under the Animal Welfare Act of 1985, scientists are required to ensure the "psychological well-being" of every primate in their labs. And the U.S. Department of Agriculture, charged with implementing the law, has been working on regulations that may mandate, among other things, larger cages, increased contact with other animals, and "enriched" environments. The new rules, currently being reviewed by the Office of Management and Budget, may cost research institutions more than $100 million in capital expenditures for primates alone. Yet no one knows if spending this money would have the desired effect. "The law is way in advance of the technology," says Spinelli. "We are in our infancy in studying this. We don't know what constitutes psychological health for a primate." If anyone has a clue about contented research monkeys, it should be Spinelli. Five years ago, he hired Markowitz, one of the nation's top zoo behaviorists, to take a look at UCSF's small colony of primates. This was long before Spinelli even suspected that Congress would mandate "happiness" in primate labs; at the time, he was just concerned about the animals under his care. "I wasn't totally convinced that our animals weren't content," says Spinelli. "But I thought there had to be a realistic appraisal." We saw abnormal behavior among primates and dogs that seemed to indicate psychological discomfort," "I thought that if we are able to relieve that, it's our responsibility to do so." Since then, working at UCSF and its sister university at Davis, Markowitz has performed some of the first experiments designed to probe the reaction of laboratory animals to nonresearch-related enrichment in the environment. The blue boxes are his most ingenious - and effective - invention. Tough enough to stand up to battering by the animals, they are so simple to operate that any curious monkey is likely to stumble upon the secret of the food-pellet switch and the radio on-off switch. In fact, that is part of the point. No one teaches the monkeys how to work the switches; the animals must find out by trial and error. A computer records how often the switches are used and "ups the ante" on the food switch, so that an experienced monkey must press the switch many more times than a novice to get a treat. By learning to obtain something that interests them, Markowitz explains, the animals gain a sense of control over their environment. Have the boxes made the monkeys more contented? Spinelli is cautious, but hopeful. It is too early to tell whether the devices themselves have made a difference, he says, or whether the animals are simply reacting to the nonthreatening presence of people observing how the monkeys use the toys. But there has been a measurable improvement in the creatures' behavior. Instead of banging their cages and screaming out threatening displays, UCSF's rhesus monkeys and macaques now peer curiously at human visitors. None somersaults or paces repeatedly in the characteristic pattern of boredom and stress. They all seem healthy and well-adjusted. Even if devices like Markowitz' versatile blue boxes work for rhesus monkeys and macaques, however, they may not be the answer for all species. Kathryn Bayne, a veterinarian/behaviorist who is working on the problem with NIH's primate colony, believes that fostering psychological well-being may require different strategies for each species, for different ages among a species, even for different individuals. At the moment, she says, there is almost no scientific data on the effects of cage size, group housing, exercise, or behavioral enrichment. Bayne's own project at NIH attempts to gather much-needed information on enrichment possibilities. She is starting with singly caged rhesus monkeys, introducing objects such as an artificial fleece seeded with small bits of food. The monkeys forage for the morsels as they "groom" the fleece - two behaviors that would occupy much of their time in the wild. The challenge for Bayne is to document whether this enrichment continues to occupy the animals' attention. Bayne and NIH endocrinologist Douglas Rabin have also introduced pairs of females to shared cages - two cages clamped together with the doors open between them. The social arrangement, with females together and a male visible at a near distance, approximates rhesus activities in the wild. Rabin says that the monkeys appear comfortable and happy, "but that's a subjective observation." To develop its proposed regulations, the USDA's Animal and Plant Health Inspection Service consulted behaviorists like Markowitz along with groups from the NIH to the Animal Welfare Institute to the American Association of Zoos, Parks and Aquariums. But researchers are not sure that the rules will achieve the goal of psychological well-being. Take the requirement in the draft rules for larger cage sizes. "Nobody knows how big a cage should be," says Spinelli. "If that comes out as a final regulation, this institution will find the money for new cages. But you know what? That may do nothing about distressed monkeys." "Scientists and their institutions are willing and eager to make changes that will improve the psychological well-being of primates," adds Douglas Bowden, associate director of the Regional Primate Center at the University of Washington. "But they want to be reasonably sure that the mandated changes will in fact have the desired effect." Spinelli and others worry that money spent on meeting detailed regulations will be siphoned off from better means of animal care. And Richard Traystman, professor of medicine and head of the animal care committee at Johns Hopkins, believes that the animal rights groups' ever-escalating demands for costly renovations may just be a tactic designed to make animals too costly for research. Traystman says, "There has to be some scientific basis to make sure that what we're asking for in renovation is appropriate. We don't want somebody coming along five years later and saying, oh, that was wrong." Meanwhile, many researchers have taken it into their own hands to foster the well-being of their animals, if only because well-adjusted monkeys are vital to doing good science. Spinelli says UCSF investigators were willing from the beginning to enroll their monkeys and macaques in Markowitz's studies, often out of affection for their animals. But this year, he says, "I've got researchers banging on my door wanting us to build a new room for their monkeys," The scientists, who prefer to remain anonymous, are trying to design a stress-free environment for their monkeys; their studies on brain function cannot be done if the animals are even mildly distressed. At NIH, Douglas Rabin is measuring the response of the female reproductive cycle to specific hormones. If his monkeys are under stress, endogenous elevations of cortisol or ACTH could seriously affect his data. So Rabin has consulted Bayne and other NIH vets to come up with his own ad hoc means of comforting and socializing his monkeys. He houses them in double cages and hand-feeds and combs them, establishing a trust that will allow him to draw blood samples from a catheter without using a permanent tether or tight restraints. "It's important for the data but it's also important for how you treat your patients," says Rabin. "I'm basically a physician, so I guess I look at the monkeys like they're not just my research property, they're an animal that's like a patient." -- J.E.B

What Can Scientists Do To make Animals 'Happier'

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