Rat-monkey

RAT-MONKEY
Other colloquial name(s): forest goblin
Genus & species: Nothosimius peterjacksonii (family Muridae, order Rodentia)
Meaning of: Peter Jackson’s false simian
Ancestral creature: Brown rat Rattus norvegicus

Upper right: forepaw showing second digit modified as thumb
Mid right: Rat-monkey skull showing distinctive teeth
Lower right: ancestral rat and detail of primitive forepaw

The species name honors director Peter Jackson, whose 1992 film “Braindead” featured a creature half-rat, half-monkey. Unlike its vicious cinematic namesake, the rat-monkey does not have a venomous bite that turns people into zombies!

Rat-monkeys are interesting in that their origin can be directly attributed to a parasite, the Toxoplasma gondii paramecium, which caused the disease Toxoplasmosis. Originally, felines were the organism’s primary hosts, and the asexual phase of its lifestyle was spent in rats and mice. The parasite directly affected the behavior of the rodents, making them drawn to the scent of cat urine, which would normally drive them away. When the engineered plagues at the end of the human era threatened to wipe out most species of felines, the T. gondii parasite underwent several mutations as it desperately attempted to find a form that would survive. Eventually, it died out, but not before some of the paramecium’s genes were directly imprinted into those of its rodent hosts. The jumping genes had a more scattershot effect on the rat’s brain, causing affected individuals to lose their normal fears of open spaces and unfamiliar foods. Obviously, many rats inheriting these genes died. But with the lack of predators and rapidly changing environs that marked the end of the human era, it was the fearless rats that braved new environments while their unaffected kin cowered in the shadows, and survived to radiate into many new species, among which the rat-monkeys are the most visible and commonplace.

There are several species of rat-monkey. Pictured is the most common, Nothosimius peterjacksonii flavus, the Golden Caped Rat-Monkey, named for its color and the thick cloak of long hairs on the shoulders of the male. The average rat-monkey is about 12-20 inches long, with a bare, scaly tail of the same length, weighing up to twelve pounds with a brain capacity of 40 grams, the males being slightly larger. They are omnivores, eating a wide variety of fruits, nuts, insects, small animals, and eggs. They have been observed to make and use simple tools, and are likely among the brightest animals now alive. They posses a complex system of calls, many of which are above the range of human hearing, which almost approaches a language.

Their social structure is fascinating, unlike many other mammals. Young males woo the unbonded females by building nestlike bowers decorated with bits of bone, shell, feathers, flowers, shiny stones and other eye-catching trimmings. The females are the more aggressive gender, viciously driving off other females that seem interested in the same male. When the 2-4 young are born, the female only nurses them for a few weeks before passing them off to the male, which has the unique ability to lactate. The larger, stronger male stays at the home nest, nursing and protecting the young, while the quick, agile female goes on expeditions to gather food. Several males, usually close relatives, may nest near one another for protection, but the advantages gained by close association are almost negated by the constant low-key squabbling of the females. When the young are older and before the breeding season begins again, the rat-monkeys will travel in loose associations of several bonded pairs (again, the males are typically relatives). Young rat-monkeys stay with the father for several years before striking out on their own, and are ready to breed at 5 years of age. Wild rat-monkeys can live up to 30 years, with 20 years being the usual lifespan.