Potter Stewart, a former Justice of the US Supreme Court, famously said of hard-core pornography that it was hard to define but he knew it when he saw it. His process of discrimination was far from unique: with regard to pornography, many people feel similar confidence in their own reactions. But this gut consensus has not led to shared definitions or universally accepted policies. That is to say, when they see any particular “it,” some people know it and some do not. A parallel juxtaposition of convergent method and divergent results exists with regard to wild animals. Even people accustomed to thinking critically about the more general notion of “wilderness” often rely on less consciously formulated criteria to categorise a particular animal or group of animals as wild. And, as is the case with pornography, there are some good reasons for this inconsistency. Both pornography and wild animals inspire strong and diverse emotions. And both are genuinely difficult to define and delimit.

Leaving pornography aside, there is no obvious line or boundary that separates wild animals from those that are not wild. Instead, there are expansive grey areas, of which the most conspicuous encompass the domesticated animals that have reverted to a life outside human control, and the undomesticated animals that thrive within human environments. And these definitional difficulties have been compounded by a protracted shift in historical valence. To put it in a nutshell, in the course of the eighteenth century (and at least in the view of some fortunate people in some contexts), wild nature began to seem less terrifying and more exhilarating. As has been frequently recognised by scholars, Romantic art and literature provide profuse evidence of this major transition in Western sensibility. It is the reason that nineteenth-century travellers, like their twenty-first-century successors, admired stark mountain landscapes and stormy seas. This shift also affected activities and institutions whose professed focus was more pragmatic. It can, for example, be traced in the practices of the nineteenth-century zoos and, especially, in the acclimatisation societies with which they were often associated. In these settings, the exotic and wild was converted into the domestic or domesticable, at least in theory or aspiration.

When the zoological garden at Regent’s Park opened its gates to the public in 1828, a small area was reserved for what were termed breeding experiments.¹ (These quarters soon proved inadequate and unsuitable, and they were exchanged for a farm outside the city.) It accommodated various species of deer, sheep, goats, zebras, kangaroos, zebu cattle, rabbits, ostriches, emus, gallinaceous fowls (wild relatives of chickens and turkeys), ducks, and geese. These animals had been selected to accommodate a much narrower human constituency than the one that was drawn to the main menagerie. Many of the zoo’s most eminent patrons were also elite agriculturalists with a lively interest in the breeding of domestic animals. In its 1829 report the Council of the Zoological Society defined the primary objective of the farm as “effecting improvements in the quality or properties of [domesticated quadrupeds and birds] used for the table; and likewise in domesticating subjects from our own or foreign countries, which have not hitherto been inmates of our poultry or farm yards.”² This formulation both privileges wildness and conflates it with domestication; at the peak of early enthusiasm for pedigreed breeding it implies that a hybrid infusion of wildness might be as desirable as the inbred purity documented in breed books.

As it turned out, the farm’s first years were its only years. Maintaining live animals was and is expensive, and the young Zoological Society’s finances were in any case fragile. Decades later, in the 1860s, the Society for the Acclimatisation of Animals, Birds, Fishes, Insects and Vegetables within the United Kingdom, whose sole purpose was to encourage such introductions and crossings, also fizzled. But its French model, the Société d’Acclimatation, which benefited from both official support and an extensive colonial network, enjoyed much greater success. Founded in 1854, it encouraged the introduction of wild and domesticated exotic animals with equal enthusiasm. Hybridisation was a persistent preoccupation of the members, and longhaired goats were special objects of desire. At the society’s annual prize giving in 1911, the president praised the recipients for having “created the most beautiful and productive races, the best adapted to our needs, which have become for us a source of profound joy.”³

Before the society was a decade old, its Jardin Zoologique d’Acclimatation opened its gates in the Bois de Boulogne. As its name suggests, it was conceived as a hybrid institution. It included the attractions that had become standard for a zoological garden and that were consequently required by the general public—big cats, elephants, and other iconic animals. But these constituted only a part of its collection, and not the most important part, at least in theory or in principle. Its core mission was much more pragmatic, distilled in the term “applied zoology.” The zoo was intended as a laboratory for the study of acclimatisation, and its priorities were distinctively pragmatic. Thus, its initial displays emphasised the economic potential of animals from French colonies (Algeria turned out to be a permanent preoccupation, both as a source and a target of acclimatisable animals), and it housed the largest collection of exotic agricultural animals in Europe.⁴

The most robust and effective acclimatisation societies, however, were established on the other side of the world, in the British colonies of Australia and New Zealand. In 1861, the Acclimatisation Society of Victoria described its objects in much the same language as that used in Britain: “the introduction, acclimatisation, and domestication of all innoxious animals, whether useful or ornamental; the perfection, propagation, and hybridisation of races newly introduced or already domesticated, [etc.]”; and this language was subsequently borrowed by similar societies elsewhere in Australia and New Zealand.⁵ As with the European societies, it would be difficult to extrapolate a clear sense of what was wild and what was domesticated from the species that they acquired and nurtured. The range of mooted targets was as ambitious and fanciful as it was in Britain—including babirusas and giraffes, as well as the more plausible antelope, deer, sheep, and goats. Within a few years of its foundation, the Acclimatisation Society of Victoria owned camels, llamas, alpacas, hares, several species of goat, sheep, and deer, and various kinds of birds and fish. The focus on consumption (that is, ingestion) was equally strong. As in Europe, it was hoped that antelopes would offer a change from the monotony of beef and mutton, and that the appealingly large South American curassow could supplement more pedestrian fowl. Even the Australian fauna, which were routinely derogated by acclimatisers on both utilitarian and aesthetic grounds, could be drafted to serve in this campaign. Adventurous eaters claimed that “the flesh [of the wombat] is always . . . a great treat”; “the opossum is good . . . especially when curried or stewed”; and “the monitor lizard . . . if one could overcome the repugnance of its appearance, is delicate and excellent food.”⁶ A celebratory dinner, held in a Melbourne hotel in 1864, was described as a “fitting tribute to the cause of acclimatisation . . . [and] also a complete triumph of gastronomy. . . . Among the entrees were curries, pates and salmis in which wombat, bandicoot, and parroquet figured conspicuously.”⁷

Despite the eccentric tone of much acclimatisation-related discourse (and behaviour, for that matter), in both Australia and New Zealand, acclimatisation societies received public support, albeit inspired by varying degrees of official enthusiasm and inspiring varying degrees of taxpayer outrage. At least in some places, they were endorsed by God as well as by Caesar; thus parish clergymen in Victoria attempted to persuade their flocks that “a society which multiplies . . . the gifts of an All Bountiful Creator . . . is worthy of the support not only of the Philosopher but also of the Christian.”⁸ In both places the acclimatisers also had to deal with mounting suspicion that some of their introductions were doing more harm than good: the Australian societies, for example, repeatedly swore that they were not to blame for what had quickly become a plague of rabbits. Even the journal Nature chimed in from 12,000 miles away, stating that “the English Acclimatisation Society fortunately came to an end before it could do any harm here; but its example has been mischievous in our dependencies.”⁹

Thus enthusiastic acclimatisers could seem irresponsible as well as eccentric. But the often radical disjunction between their ostensible goals and the species that they suggested as the means of realising those goals can also be seen as a concrete expression of an ambiguity that similarly bedevilled sober naturalists. Identifying species—that is, the limits of species—had always been both necessary and problematic. The conventional definition of the boundary between similar organisms—the ability to produce fertile offspring—was clearly disregarded by many animals (and even more plants). Nineteenth-century zookeepers enjoyed experimenting with interspecies and intergenus crosses, and zoogoers admired the resulting hybrids between donkeys and zebras, domestic cattle and bison, and dogs and wolves.

This ambiguity has been distilled in the classification of domesticated animals—that is, none of them has become sufficiently different from its wild ancestor to preclude the production of fertile offspring, and some mate happily (or at least effectively) with more distant relatives. Despite these persuasive demonstrations of kinship, however, from the eighteenth-century emergence of modern taxonomy, classifiers have ordinarily allotted most types of domestic animal their own species name (rabbits and pigs are exceptions). Domestic sheep are still classified as Ovis aries while the mouflon is Ovis orientalis, and dogs are Canis familiaris while the wolf is Canis lupus. This practice has much to recommend it in terms of convenience, but it also constitutes an acknowledgment both of the difficulty of distinguishing between wild animals and their domesticated kin, and, nevertheless, of the felt importance of doing so.

The implications of making or not making such distinctions extend beyond the intellectual realm. As the activities of nineteenth-century acclimatisers show, they construct the physical world at the same time as they describe it. And, of course, they still do so. The advent of DNA analysis in recent decades has made it both easier to distinguish between domesticated animals and wild ones, and more difficult. For example, the Scottish Wildcat Association was established in 2007 to protect the small remaining British sub-population of the very widely distributed species ancestral to domestic cats. (Of course, the fact that such creatures are considered worthy of protection signals a distinctively modern valuation of wild animals; Victorian gamekeepers hunted down the ancestors of these animals and nailed their skins to barn doors.) The targeted felines strongly resemble domesticated tabbies, although they tend to be larger and more irascible. Perhaps for this reason, the distinction between pure wild animals and those contaminated by miscegenation featured prominently on the Association’s website: “In 2004 a team of scientists . . . estimated that 400 wildcats remained, the other 5000 or so being feral domestic cats or hybrid mixes of domestic and wildcat.” It further advocated “improving legal protection, launching a public awareness campaign, supporting the captive breeding program and creating special reserves for wildcats which would in turn benefit many other species.”¹⁰ As a result of these efforts, the Scottish wildcat has been declared a “priority species” (at least in Scotland). In an ironic gloss on the efforts of nineteenth-century acclimatisers, it has therefore become eligible to benefit from the establishment of a studbook, a captive breeding program, and other measures that blur the cultural boundary between the wild and the domesticated, even as they attempt to reinforce the genetic boundary that separates them.

1. Peter Chalmers Mitchell, Centenary History of the Zoological Society of London (London: Zoological Society of London, 1929), 93.
2. Quoted in Henry Scherren, The Zoological Society of London: A Sketch of Its Foundation and Development, and the Story of Its Farm, Museum, Gardens, Menagerie and Library (London: Cassell, 1905), 43.
3. Edmond Perrier, “Societe d’Acclimatation: Distribution des recompenses.” Manuscript, 12 Febuary 1911. MS 2227, Natural History Museum, Paris.
4. Michael A. Osborne, Nature, the Exotic, and the Science of French Colonialism (Bloomington: Indiana University Press, 1994), ch. 4.
5. The Rules and Objects of the Acclimatisation Society of Victoria (Melbourne: William Goodhugh, 1861), 3.
6. George Bennett, Acclimatisation: Its Eminent Adaptation to Australia (Melbourne: William Goodhugh, 1862), 19.
7. “Acclimatisation Society’s Dinner held at Scott’s Hotel, Collins Street West, on Wednesday, July 6th, 1864,” The Yeoman.
8. Circular letter from E. Wilson to parish priests, March 1864. Victoria State Library SLT 285.2945.M24.
9. Nature (1872), quoted in Hawkes’s Bay Acclimatisation Society Centenary 1868–1968, ed. Joyce M. Wellwood (Hastings, NZ: H. B. Acclimatisation Society, 1968), 24.
10. Scottish Wildcat Association, accessed in 2014, http://www.scottishwildcats.co.uk/wildcat.html.