The onza - a success for cryptozoology

The onza, the mysterious big cat of Mexico, is a cryptozoological success story.

That may sound funny, considering the only whole specimen examined was a definite member of the known species Puma concolor, the puma, panther, or cougar.  But bear with me. 

First, the story. Inhabitants of western Mexico's Sierra Madre Occidental region were  reporting a strange big cat since Aztec times. Records left by Europeans go back to the Spanish conquest, when the invaders saw both a puma and a leaner, unrecognized type of "lion" in Montezuma's royal zoo. 

     The onza was generally consigned to folklore, despite reports from Americans such as Dale Lee.  Lee, a professional hunting guide who had shot nearly 500 panthers, reported killing an onza in 1938.  He wrote that the slender, long-eared animal "differs from any of the cat tribe I ever saw."   J. B. Tinsley, in his 1987 book The Puma, reproduces photographs of this cat and of a similar beast killed by a trapper named Ruggles in 1926.
     The onza story languished until  1985, when Mexican rancher Andres Murillo shot a cat he didn't recognize.  Fortunately, the man had heard of the legendary onza and was curious enough to contact an interested friend who knew American zoologist/cryptozoologist J. Richard Greenwell.  Greenwell teamed up with a leading mammologist and puma expert, Auburn University's Dr. Troy Best, and the two brought the carcass in for study. They also tracked down two other onza skulls.  One of these dates from 1938 (it is not from Lee's specimen, so it seems two onzas were killed that year) and the other from about 1975. The onza, from the specimen, looked like a panther, but with longer legs and

a slimmer build.  The ears were long, and on the inside of the tawny cat's front legs were dark horizontal stripes.  The type specimen, a female about four years old, weighed less than 60 pounds, considerably less than a normal panther its size.  The researchers wondered at first whether the specimen was starving or diseased, but it proved to be healthy and well-fed.
     As Dr. Best explained to me even before the studies were complete, one specimen and two skulls don't provide enough material for a conclusion about the onza's classification.  I wrote in 1995 that "We may be dealing with a panther subspecies, a local variation, or even just a recurring abnormality born of normal panther parents.  A complication is that there are few "normal" puma specimens from that region of Mexico to compare the onza with."

     Well, eventually a full analysis was done and published, and there was no longer any doubt about the puma identity.  It wasn't even named as a new subspecies.  It appears to be an oddball, born occasionally the way the strikingly marked "king " cheetah of Africa is, to normal-looking parents.  We don't know how common an occurrence this is, but it certainly isn't frequent: no one has claimed a new onza specimen since.

     So why was this a success? Because the animal was identified. A proper scientific  investigation was done.  And, most importantly, in the late 20th century on a relatively well-known continent, a strikingly different animal reported by witnesses recent and historical was confirmed to exist. That the appearance is essentially skin-deep, and the animal wasn't a new type, is secondary. Like the elephants of Bardia National Park (huge, dome-headed specimens of the Indian elephant), the most crucial thing is that witnesses who said they saw a weird-looking large mammal were right. Such witnesses are not always right, but they were this time. Mother Nature, it turned out, still had her secrets.

Bille, Matt.  1995. Rumors of Existence. Hancock House.

Best, Troy.  1993.  Personal communication, January 15.

James, Jamie.  "Bigfoot or Bust,"  1988. Discover, March. 

Greenwell, J. Richard. 1992. Personal communication, July 7.
Marshall, Robert E.  1961. The Onza.  New York: Exposition Press.
Shuker, Karl.   2012. The Encyclopedia of New and Rediscovered Animals. Coachwhip Publications.

Tinsley, Jim Bob.  1987.  The Puma.  El Paso: Texas Western Press.