Essay On Didelphis Virginiana

Behavior Although mostly terrestrial, Didelphis virginiana also uses arboreal and aquatic locomotion. On the ground, its gait resembles that of primitive mammals [6], which is unsurprising given that opossum-like mammals first appeared over 65 million years ago around the time when the dinosaurs were going extinct [12]. Though the opossum’s arboreal locomotion is aided by the adaptations mentioned earlier, it is still relatively slow and clumsy. However, it is a strong – if slow – swimmer, and often uses swimming as an escape mechanism. When swimming, it either uses a movement similar to its gait on land or a pacing movement (the two limbs on each side move in sync with one another and alternate with the limbs on the opposite side) [3]. Didelphis virginiana is primarily nocturnal, so it does its foraging at night. Although its …show more content…
One main one is called a bluff, in which the opossum crouches down, bares its 50 sharp teeth (the most of any North American mammal), and makes snarling, hissing, and screeching noises in order to make itself seem more formidable. It also shows remarkable healing capabilities with regard to fractures and discourages predators by defecating and secreting a foul smelling liquid from anal glands [4]. As a last resort, it will have an involuntary response to inescapable threats and feign death. During this response, it will fall over onto its side, lie curled up with its mouth wide open, and secrete copious quantities of drool from its unusually large salivary glands as well as the aforementioned liquid that give the opossum the scent of carrion (see Figure 6). During this catatonic state, which may last anywhere from a few minutes to a few hours, it will not respond to stimulus in order to further support the impression of death [3]. Interestingly, younger opossums are more prone to this reaction than adults, possibly because adults are more experienced and less likely to