Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: SATURDAY, April 20, 1991 TAG: 9104200027
SECTION: EXTRA PAGE: E-1 EDITION: METRO
SOURCE: MARGARET FALKINER/ LANDMARK NEWS SERVICE
DATELINE: NORFOLK LENGTH: Long
The zoo staff suspected the music had moved them, but nothing else happened.
Then, last Halloween, the Maury High School band led a similar parade. This time the effect was clear.
Zoo personnel said they had never witnessed such carryings-on. Rufus romped around in the dry moat at such high speed that bystanders feared for his safety - and all observers agreed that mating would have occurred had Jessie been in heat.
"There is just no doubt now that the band music really turns those rhinos on," one observer said.
Now, Dr. Joseph Daniel thinks he knows why: the low-frequency harmonics of the band instruments mimicked seductive "pillow talk" frequencies used by the rhinos.
Last month, Daniel, dean of sciences at Old Dominion University and chairman of the Virginia Zoological Society's Animal Studies Committee, spearheaded research at the zoo that shows rhinos are communicating something at frequencies far too low for the human ear to detect. It's a sort of rhino rumble that seems to emanate from their ample bellies, not their throats.
The discovery of the "infrasound" conversations between rhinos and its apparent resemblance to some band music could help save rhinos.
Scientists hope they'll be able to learn the rhinos' sounds of love, soft and tender, and reproduce them with computers or maybe marching bands. They hope baby rhinos will result.
There are five remaining rhino species - the Sumatran, Javan, Indian and two African species, black and white. The animals face possible extinction in the wild, and total extinction would follow unless they reproduce in zoos.
Some of the species could be extinct in the wild within 20 years, though several nations in recent years have implemented ambitious rhino-preservation programs, setting aside new preserves and vigorously enforcing anti-poaching laws.
So far, zoos have somewhat improved the rhino's survival chances. In 1987, in zoos worldwide, 10 rhinos of 3 species were born; for 1988 the total was 15, for 1989 it was 13. Unless these birthrates improve, however, zoo rhinos would be gone soon after the wild ones.
Rufus and Jessie are white rhinos. They don't like to mate except under herd conditions, which few zoos can supply.
For years, zoos have sought a rhino aphrodisiac, be it scent, sight or sound.
Once, the Virginia zoo staff tried creating "herd conditions" by strewing rhino urine and feces from other zoos around the rhino yard. The rhinos found this interesting but failed to mate, said zoo superintendent Gary Ocshen-bein. Another time, keepers hid behind cardboard cut-outs of rhinos while circling the rhino compound, trusting that the animals' poor vision would deceive them. "We didn't try that during public hours," one keeper said. "Visitors would have thought we were crazy - just like the rhinos did."
One zoo reported some success when it used huge sections of polished aluminum as mirrors around its rhino yard, thereby seeming to transform two animals into a whole herd.
But nothing moved the rhinos like the marching bands.
The discovery that music might excite the savage beast has opened the door to talking with rhinos and other large animals - and not just about sex.
"It seems that some of the larger animals are talking much of the time," Daniel said. He believes that exploring low-frequency animal sounds, known as infrasonics, may offer new ways not only to communicate with animals but also to help endangered species.
Scientists have known for several years that elephants vocalize on low frequencies, Daniel said, and it had never made sense to him for such a phenomenon to be limited to elephants.
He had a hunch that infrasonics from the marching bands had caused Rufus to exhibit preliminary mating behavior. No other music - not even the loud rock band that played for a zoo gala - has provoked such a response.
Tests at other zoos
When Elizabeth Muggenthaler, an ODU honors student in psychology, set out to record the infrasound of Virginia zoo elephants, Daniel encouraged her to test the rhinos too.
To the delight of zoo staff, sophisticated equipment borrowed for the occasion showed that the rhinos were, indeed, vocalizing in infrasound. The first recording occurred as the pair met after a short separation. Only the male spoke, on a frequency of 30-35 cycles. (Humans hear little below 200 cycles. Most human conversation is at 1,000 to 4,000 cycles.)
The equipment was taken to the Knoxville Zoo in Tennessee, National Zoo in Washington and Bronx Zoo in New York to confirm the data. At all the zoos, more rhino "talk" cascaded across the graph paper.
Tests of the hippos at these zoos soon revealed that they, too, were communicating in similar fashion.
Daniel suspects that the apparent ability of some of the large ungulates, or hooved animals, to communicate in infrasound has something to do with their size. "The sounds that they make," he said, "seem to be resonating through their bodies rather than coming from their throats."
More than coincidence
At age 18, Rufus and Jessie are at least a decade past the usual age for rhinos to begin mating. The same untarnished celibacy that has caused despair among the zoo staff now makes the pair perfect for study.
If they mated during or immediately after deliberate use of sound by humans, it would be unlikely that the event was coincidental. The experiment could be repeated with greater confidence to help stave off the extinction not only of rhinos but also of other animals with specialized breeding requirements.
Muggenthaler believes it may be possible to talk with some animals in their own inaudible language. "I hope," she said, "to use computer-generated signals that match theirs, so I can perhaps elicit a response."
If so, zoos could dispense with such shabby tricks as rhino pinups, mirrors and borrowed urine and try a more classic route to romance: the right music at the right moment.
Is a concert in the offing?
Indeed, and according to Daniel, it will be planned entirely for the listening pleasure of the rhinos - a notion that clearly delights him. Lots and lots of band instruments will be played. "We must test them one at a time," he said, "recording both the sounds we can hear and the sounds we can't, and watch the animals' responses."
The courting concert for Rufus and Jessie is on hold till $150,000 is raised toward establishment of a special breeding refuge on property owned by the city of Norfolk at St. Bride's in southern Chesapeake. That money will match $150,000 previously donated for the refuge by the Mars Foundation of Northern Virginia.
Rufus and Jessie will be the first animals taken to the refuge. Perhaps a spacious new pasture, together with electronic equipment playing the inaudible love songs of their species, will finally make them want a herd of their own. But she never expects to get much talk from giraffes. She is convinced that complex animal sounds have much to do with intelligence - "and to be honest you can just look at a giraffe and tell there isn't much going on in there."
by CNB