“Some regulations were rolled out perhaps without a lot of data on whether it’s the best thing for animals. Now people are saying we need to look more closely.”
APA’s Committee on Animal Research and Ethics
presenting the items in a series of pairs so that the cats could
choose their favorite of two. They found an animal’s favorite
pastimes tend to square with what it would be doing if it were
living in the wild. On the savannah, for instance, female lions
do most of the hunting. In the zoo, Miller found, females prefer
to interact with “boomer balls,” large plastic balls they can
pounce on and sink their claws into. Males, which in the wild
would be out marking their territories, are more interested in
fresh branches that they can mark with their scents. Providing
opportunities to express these gender-specific behaviors makes
for happier cats.
“We let the animals tell us what they want to interact with,”
Miller and his colleagues are also working to validate
behavioral measures of animal welfare, using cheetahs and
okapi as test cases. They’re collecting behavioral information
about the animals, as well as physiological data such as the
amount of stress hormones in the animals’ droppings. They
hope to determine which behaviors indicate good health
and which might be signs of a problem. By codifying those
behaviors, zoos could rigorously test new enrichment methods
without expensive hormone assays.
“It costs a lot of money to run assays,” Miller says. “If we can
validate behavioral measures that tell us the same thing, it could
be a tool that other institutions could replicate.”
urge cleanliness and sterility. But nature is anything but sterile.
While cleanliness is important, it’s worth investigating whether
we may be taking it too far, she says.
As researchers take a critical look at enrichment, they’re
sometimes surprised by the results. Take music: Some
researchers have turned on the radio for their laboratory
subjects, assuming the animals would enjoy it, Bennett says. But
melodies that are pleasing to our ears may not be so charming
to animals. University of Wisconsin–Madison psychologist
Charles Snowdon, PhD, and University of Maryland cellist
David Teie discovered that cotton-top tamarins were unmoved
by most human music. Yet the monkeys showed signs of either
anxiety or calm when responding to various songs composed
using elements of the tamarins’ own calls (Biology Letters, 2009).
Animal-care practices also deserve a second look, says
Bennett. For example, she says, animal-care guidelines typically
Research with cotton-top tamarins showed that they were
indifferent to music that many humans enjoy.