EUGENE M. MCCARTHY, PHD GENETICS, ΦΒΚ
The pilots, who risked their lives at sea, were inclined to regard cosmologists as impractical dreamers.
Over the Edge of the World
Scholars (specifically, biologists) say hybrids between cats and brush-tailed possums (Felis catus × Trichosurus vulpecula) are impossible. The claim is that the two are simply too distantly related to produce progeny together. And yet, there are many eyewitness reports from ordinary Australians claiming that such possum-cat hybrids do in fact exist. They have seen them with their own eyes, they say. They and their friends have owned them and lived with them for years. For example, one resident of Branxholme, Victoria wrote in to The Argus, the Melbourne paper, to say that he “had one of these animals for 14 years.” So who’s right? The scholars? Or the witnesses? Various claims of this sort are quoted below.
But before turning to those reports, it might be worthwhile to touch on a related topic. Recently, in reading a biography of Magellan, Over the Edge of the World, by Laurence Bergreen (2004), I ran across another situation in which scholars were at variance with ordinary observation. In this case, however, it was cosmologists and sailors. Cosmologists were the medieval answer to modern geographers, cartographers and astronomers. Their goal was to describe the structure of the universe, including the geography of the earth. However, cosmologists were university scholars who pondered geography from the armchair, untraveled thinkers expert in an intellectual tradition handed down from ancient times. In contrast, there were the ordinary pilots of voyaging ships, who collected geographic information firsthand as a practical matter essential to their line of work. As Bergreen (p. 11) comments,
This situation led scholars, who long remained ignorant of the new discoveries of mariners, to make gross errors in their maps. For example, they would far undercalculate the earth’s circumference and omit the Pacific Ocean, one-third of the surface area of the world. And it seems a similar situation may exist today in which scholarly biologists, secure in their confidence that they know what’s possible with hybrids and what is not, look down on and dismiss anecdotal reports such as those quoted below. Let’s hope that the magnitude of any resulting error in biological thought falls short of the vast blunders of the cosmologists.
In 1872, Alexander Callender Purdie (1824-1899), a member of the Royal Society of New Zealand, discussed before a meeting of the society (Purdie 1872), an alleged hybrid of this sort, which he says was “presented to the society by Mr. Jennings as a cross between a cat and an opossum, said to be bred by Mr. Jones, of Ballarat, Australia.”
It seems clear that the specific animal Purdie was referring to when he says “opossum,” was Trichosurus vulpecula, the Common Brush-tailed Possum, which was the only animal familiarly known in New Zealand as an opossum at that time. It seems that in the late nineteenth century Australia, too, opossum was commonly used in referring to T. vulpecula. The name later became shortened with an apostrophe to ’possum and still later the apostrophe was dropped to form the modern name possum. Trichosurus vulpecula is native to Australia, but introduced in New Zealand. It has the widest distribution of any Australian mammal. Nowak (1999, p. 93) comments that “Because of its fecundity and adaptability to a variety of conditions. T. vulpecula has been compared to the Virginia opossum (Didelphis virginia) in North America. Both species seem able to live near people and even to expand their range in the face of human development.”
What seems to have been a hybrid of the same type was briefly described in a Sydney newspaper five years later. The account appeared on page 555 (cols. 3 & 4) of The Sydney Mail and New South Wales Advertiser November 3, 1877. It refers to a “lusus naturae which turned up at a township on the other side of the river, in the shape of a cat. This animal has fore paws exactly resembling those of an opossum, whilst the hind feet are precisely similar to the feet of a kangaroo. In other respects this monstrosity displays no special departure from the ordinary feline type” (source).
A spate of correspondence to the Melbourne-based newspaper The Australasian began in the spring of that same year with the following letter, which appeared on page 24 of the June 2, 1877, issue (source):
A letter about a fertile cat-possum hybrid appeared later that month on page 25 of the June 23, 1877, issue of The Australasian (source):
Earlier that same month, another, longer report, describing another fertile hybrid, appeared on page 24 of the June 16, 1877, issue of The Australasian (source). It reads as follows:
(There is, of course, a widespread belief that hybrids are always sterile, an old wives’ tale extensively debunked on this website.)
Such hybrids have been alleged for a very long time. An earlier report appeared on page 18 of the November 7, 1853, issue of the Adelaide Times, a newspaper published in Adelaide, South Australia (source). It reads as follows:
Moving forward in time, a ten-year-old writes in to the author of a children’s column, “Mr. Flamingo.” The letter appeared on page 2 of the March 25, 1899, issue of the Launceston Examiner, a newspaper published in Launceston, Tasmania (source):
And then we have the following from page 2 of the January 14, 1907, issue of The Bendigo Independent, a newspaper published in Bendigo, Victoria (source). It reads as follows:
A report of a similar nature appeared on page 18 of the January 24, 1920, issue of Smith’s Weekly, a newspaper published in Sydney, New South Wales (source). It reads as follows:
Proceeding in chronological order, the next possum-cat hybrid made its way onto page 2 of the September 1, 1934, issue of the Recorder, a newspaper published in Port Pirie, South Australia (source):
The Argus (May 14, 1936, p. 4), a newspaper published in Melbourne, carried the following piece of reader’s correspondence (source):
Another report about a possum-cat hybrid, which produced offspring, appeared on page 3 of the August 31, 1939, issue of Queensland Country Life, an Australian newspaper published in Ormiston, Queensland (source):
It’s of interest that this last report (1) gives the direction of the cross, male possum × female cat; (2) says that a female F1 hybrid was produced; (3) that this hybrid successfully backcrossed to a male cat and produced a female B1 hybrid; (4) and that this B1 female backcrossed again to a male cat and produced two progeny.
So then, it has not only been alleged that possum-cat hybrids exist, but also that the female hybrids are sometimes fertile in backcrosses (which is consistent with Haldane’s Rule). Another news report, which appeared in The Argus (Nov. 10, 1933, p. 7) stated that a possum-cat owned by a local resident also produced “kittens” in a backcross to cat (source). But, of course, claims that possum-cat hybrids exist and that they are sometimes fertile require experimental confirmation. The present collection of reports is intended to elicit such experimentation.
Clearly, any such cross would be quite distant. T. vulpecula is a marsupial and Felis catus, a eutherian mammal, so this hybrid would be between animals belonging to what are usually rated as distinct superorders or subclasses (Marsupialia and Eutheria) of Order Mammalia. However, the very disparity of this cross—and the allegations that the resulting hybrids are sometimes fertile—makes it all the more interesting.
See also the related article “Opossum-cat Hybrids.”
The following is a list of reported cat crosses. Some of these crosses are much better documented than others (as indicated by the reliability arrow). Indeed, some might seem completely impossible. But all have been reported at least once. The links below are to separate articles. Additional crosses, not listed here, are covered on the cat hybrids page.
By the same author: Handbook of Avian Hybrids of the World, Oxford University Press (2006).
Human Origins: Are we hybrids?
On the Origins of New Forms of Life
Cat-rabbit Hybrids: Fact or fiction?
Georges Cuvier: A Biography
Prothero: A Rebuttal
Branches of Biology