To Snare the Nimble Marmoset

As the ecological details of the natural environment pervade a text, the reverse is sometimes equally true - a text might colonize the natural environment, if only through influencing the dreams and behaviors of its readers. 

Eugene Schieffelin was an eccentric drug manufacturer in the early twentieth century who dreamed of introducing every species of bird mentioned in any of Shakespeare’s plays into North America. His attempts to establish wild populations of bullfinches, chaffinches, nightingales, and skylarks in the new york area never came to fruition. However, a population of starlings he released in central park grew from sixty to one of the predominant invasive species in the US [1]. 

This anecdote illustrates a related idea - as an island can be colonized by the mainland, the reverse may also occur. In this case, birds from an imaginary world first colonized an island (Manhattan) and then overran an entire continent (North America). 
Natural history of the animal kingdom for the use of young people.
Brighton :E. & J.B. Young and Co.,1889.
Source: Biodiversity Heritage Library
Schieffelin's starling isn't the only member of Shakespeare's bestiary that demonstrates success in colonizing human-dominated environments. 

         I prithee, let me bring thee where crabs grow
         And I with my long nails will dig thee pignuts, 
         Show thee a jay’s nest, and instruct thee how
         To snare the nimble marmoset. I’ll bring thee
         To clustering filberts, and sometimes I’ll get thee
         Young scamels from the rock. Wilt thou go with me? 

                                                (The Tempest, II.ii.78-83[2]

These lines are spoken by Caliban, the "savage" native inhabitant of the Desert Island where Shakespeare's play The Tempest is set. Caliban mentions several unusual animal prescences on the island - jays, scamels, and marmosets, among others. Portrayed in the text as "hidiously deformed," hunchbacked and only partially human, Caliban might have identified with the marmoset - as Caliban is “half man, half fish,” the marmoset also straddles a strange place between kingdoms of classification. Most mentally advanced primates have fingernails - marmosets have claws, among other primitive features not generally associated with that order of animals (which is to say, "advanced" animals like chimpanzees and humans). Their brains are much smaller than those of other primates their size. 
Johnson's household book of nature
New York,H.J.Johnson,[1880]. 
Source: Biodiversity Heritage Library
In spite of their low status by any taxonomist's estimation, these animals have proven themselves surprisingly adept at eking out a living in unexpected environments, be it as islanders or as colonists - and have found prosperity in our own century colonizing a modern sort of island - the green spaces within cities, oasises of "natural" environment surrounded by seas of urban sprawl. The marmoset colonists of these islands interact daily with park-goers in many South American cities, even capturing the interest of scientists: 
The city of Belo Horizonte, Minas Gerais, Brazil, has fragments of “green areas” (i.e. natural habitat or human- cultivated vegetation) spread throughout the city with 150 of these areas being greater than 2ha in size. It is in these fragments that we encounter black-tufted marmosets (Callithrix penicillata), a primate species able to adapt to urbanized environments, probably due to its efficient ability to exploit different food sources. [3]
Whether urban living marmosets are city ‘invaders’ or animals that have become ‘stranded’ within the urban environment remains to be resolved; that is, whether they actively enter urban environments or were incorporated into urban environments due to urban sprawl. [4] 

Like Caliban, or perhaps more like Robinson Crusoe, these primates find themselves castaways in a strange microcosm. Their challenge is first to survive, and second to assert dominion over their adopted home. Like Crusoe, it's not entirely clear whether they are truly "shipwrecked," or choose to inhabit these islands for personal reasons. As Crusoe seemed to grow to prefer his island kingdom, the marmosets have also become seemingly very comfortable with island life.

Map of a city park in Belo Horizonte, Brazil
Their boundaries can be sharp and discontinuous, or gradational. They can vary from large oceanic islands, to islands of forest surrounded by grassland, to trees within the forest, to leaves on the tree. What is perceived as an island will depend on the organisms being studied ... as such they are basic functional units of ecology. [5] 
There is a suggested connection here between an island and a stage - the island is portrayed as a setting more than a geography, and the border is more or less imagined. The ecology of such a place is secondary (the mainland ecology is primary). In literature, any environment or animal represented is by definition a "secondary" representation of a first-hand experience - this distinction is important because it points to how an island is well suited to the task of literature generally - the boundaries between one realm and another are constantly in sight, even as they shift from one place to another. There is also a suggestion here that we might consider islands as the constituent building blocks of the world at large - the phrase "basic functional units" points to a theory of "island as axiom." In light of this, the ecological islands of Belo Horizonte are seeds from a single imaginary island. The role of the marmosets has shifted from "native" to "colonist," as the impassable ocean shifts from waves to high-rises. 
The zoology of the voyage of the H.M.S. Erebus & Terror. v.1.
London,E. W. Janson,1844-1875.
Source: Biodiversity Heritage Library
The marmosets also mirror Crusoe in their interactions with the "natives," if we might consider the human inhabitants of the city to be the natives of an urban environment - which is to say, they are friendly towards the park-goers when useful for the sake of being fed, but are equally comfortable with aggression and theft when necessary: 
The other common type of interaction we observed with the public involved problematic marmosets. In these cases people had fed marmosets in their houses and subsequently the marmosets had started to aggressively ‘invade’ their houses. Unfortunately, many people think it is “cute” to have marmosets feeding off their kitchen table; however, marmosets quickly lose their fear of people and start to raid houses looking for food and causing negative interactions. [6]
The marmoset's relative lack of higher intelligence, small size and adaptability make them good breeders in captivity, and they are consequently popular laboratory animals. [7] However, that same lack of higher intelligence combined with their status as a squirrel-like common pest makes them a less than fascinating subject for literature. Common and unintelligent animals rarely make good subjects for stories, unless highly anthropomorphized.

So, what were they doing on Shakespeare's island in the Tempest? There's no definitive answer to this question - regardless, their presence there provides an unwitting but still intriguing play on the idea of "boundary" within the island's domain. Like Caliban, the marmosets dance on the line between two taxonomic groups, both in their physiology and in their behavior. While Prospero and Caliban argue their rights to jurisdiction over the island, the only true "natives" in question may be marmosets. Analyses of the play often focus on Caliban as a "native" figure, portraying the play as a parable of colonialism. However, if we may consider any primate as a "sentient" being, it's the marmosets who hold the longest-standing hereditary right to dominion of this imaginary space. Therefore, I propose a reading where the parable is of taxonomy and imagination rather than colonialism - and where it is the boundaries between the individual and the environment that are at stake, rather than the boundaries of an expanding nation.  
Caliban, Sir Joseph Noel Paton, 1868


[1] Gup, Ted. 100 Years of the Starling. The New York Times. Retrieved 5 May 2013. Digital. 
[2] Shakespeare, William. The Tempest. Boston: Bedford/St. Martin’s, 2009. Print. 
[3] Leite, Giovana C. et al. Human-marmoset Interactions in a City Park. Applied Animal Behaviour Science, 2011, Vol.132(3), pp.187-192 
[4][6] Duarte, Marina H.L. et al. Designing laboratory marmoset housing: What can we learn from urban marmosets? Applied Animal Behaviour Science, 2012, Vol.137(3-4), pp.127-136
[5] Osman, Richard W. "Artificial Substrates as Ecological Islands." Artificial Substrates. Ed. John Cairns, Jr. Ann Arbor, Michigan: Ann Arbor Science Publishers Inc, 1982. pp.71-114. Print.