Speaker 1: Welcome to brain Stuff from How Stuff Works. Hey, brain Stuff,
Speaker 1: Lauren Vogelbaum. Here. If you live in North America, you've
Speaker 1: probably seen a Virginia a possum classification to Delphis Virginiana.
Speaker 1: Maybe the unfortunate creature was dead on the road, or
Speaker 1: maybe it was very much alive on your porch eating
Speaker 1: garbage in the middle of the night. But in either
Speaker 1: case you might have thought, oh, gross, a possum. But
Speaker 1: you would have been off base on several counts. First
Speaker 1: of all, possums live in Australia and are also a marsupial,
Speaker 1: which means they raise their young in a pouch like
Speaker 1: a kangaroo, but they are a completely different species. And
Speaker 1: the animal currently snuggling with a half eaten bag of
Speaker 1: Doritos at the bottom of a curbside trash can in
Speaker 1: North Carolina, which is correctly an a possum. We spoke
Speaker 1: with Richard Osfeld, senior scientist at the Caree Institute of
Speaker 1: Ecosystem Studies in Millbrook, New York. He said, folks get
Speaker 1: very confused about this. I've had people tell me triumphantly
Speaker 1: that they discovered building plans for possum nest boxes and
Speaker 1: that they planned to install dozens of them to encourage
Speaker 1: opossums to multiply on their property. But when I looked
Speaker 1: up the plans, they were designed for brush tailed possums
Speaker 1: in Australia, completely useless for apossums in North America. So
Speaker 1: with that part settled, opossums aren't that gross, even if
Speaker 1: they wouldn't mind taking that multipad tie from the back
Speaker 1: of your refrigerator off of your hands. They may look
Speaker 1: a little creepy, what with that long, hairless, prehensile tail,
Speaker 1: the mouthful of haphazard teeth, and the beady eyes, but
Speaker 1: apossums are the fastidiously groomed and most likely disease free
Speaker 1: wildlife heroes of your neighborhood. It's a common misconception, possibly
Speaker 1: prompted by their bumbling swagger, that apossums often carry rabies
Speaker 1: or a distemper. In fact, they rarely get these diseases
Speaker 1: because their body temperature is too low to make them susceptible.
Speaker 1: Not only do apossums not carry these diseases, the presence
Speaker 1: of an opossum in your yard is your best bet
Speaker 1: for combating lime disease. A two thousand nine study explored
Speaker 1: whether black legged ticks. The disease vector for lime disease
Speaker 1: might be regulated by wildlife that they parasities of fifteen
Speaker 1: forest dwelling mammals and ground nesting birds. Opossums were the
Speaker 1: only ones to destroy the vast majority of all of
Speaker 1: the black legged ticks that tried to feed on them.
Speaker 1: Over Ostfeld, who co authored the study, said, our calculations
Speaker 1: indicated that a single opossum is capable of killing several
Speaker 1: thousand larval ticks per week during the late summer peak.
Speaker 1: We also know that of those ticks that do successfully
Speaker 1: feed on an opossum, only a small fraction will become
Speaker 1: infected with the lime disease bacterium, so apossums are protective
Speaker 1: in two ways, killing ticks and preventing infection. A study
Speaker 1: by the same research team published in July ten in
Speaker 1: the journal Ecology found that tick born disease risk was
Speaker 1: reduced in areas where opossums were present. For an animal
Speaker 1: that does more than its fair share of hobbling into
Speaker 1: traffic and is known for flopping over like a corpse
Speaker 1: at the merest whiff of danger, apossums are perhaps surprisingly
Speaker 1: intelligent to begin with weak eyesight at a nocturnal nature.
Speaker 1: Both contribute to the fact that you're probably more familiar
Speaker 1: with the side of a dead apossum than a live one.
Speaker 1: In addition, their primary defense mechanism, playing dead is almost
Speaker 1: entirely involuntary, a reaction to extreme stress that leaves the
Speaker 1: apostum in a coma for a few minutes to a
Speaker 1: couple of hours, and a comatose apossum can take a
Speaker 1: beating that would kill other animals their size. This, then,
Speaker 1: is a great strategy if your mortal enemy is a bear,
Speaker 1: but not so great if it's a toyota. So if,
Speaker 1: for example, your dog corners an opossum one night in
Speaker 1: the backyard, don't worry. The apostum may hiss and show
Speaker 1: its teeth in an attempt to look scary because it's frightened,
Speaker 1: but the last thing it wants is to tangle with
Speaker 1: your four legged friend. It will invariably lay down and
Speaker 1: play dead until the threat gets bored and passes. Apossums
Speaker 1: are non aggressive, docile creatures, far more afraid than they
Speaker 1: are to be feared, and they're also fastidiously clean. Like cats,
Speaker 1: apossums are constantly grimming themselves with their paws and tongue,
Speaker 1: partly in order to make sure they're parasite free, but
Speaker 1: also to keep themselves cool. They lack sweat glands, so
Speaker 1: grooming is like apossum air conditioning, and they do it
Speaker 1: to keep themselves smelling like well nothing. As we've established,
Speaker 1: apossums aren't great at protecting themselves in a standoff with
Speaker 1: a predator, so it behooves them to stay odor neutral.
Speaker 1: Part of the reason apossums have the reputation for being
Speaker 1: smelly has to do with one other defense mechanism, the
Speaker 1: smell of death. Once an opossum goes into its theatrical coma,
Speaker 1: if a predator continues to mess with it, the opossum
Speaker 1: may excrete a smelly mucus from glands in its anus.
Speaker 1: This has been a signal, Hey, this apossum is definitely dead,
Speaker 1: and possibly so entirely dead that it'll make you sorry
Speaker 1: you ate it. Speaking of, apossums are really smart about
Speaker 1: what they eat, because it turns out they have great memories.
Speaker 1: Once an apostum tastes a chemical that doesn't agree with it,
Speaker 1: it will remember and avoid the smell of it for
Speaker 1: a year afterwards. Though apossums are immune to some things,
Speaker 1: that would poison other mammals, including most snake venoms. Apossums
Speaker 1: are biologically fascinating, which led to some confusion among earlier
Speaker 1: Europeans in the New World. Their story was the male
Speaker 1: opossum made it through the female apossums snout, which led
Speaker 1: to her sneezing out her babies into her marsupial pouch.
Speaker 1: Of course, this is not scientifically accurate, but apossums definitely
Speaker 1: do things a little differently. First of all, a male
Speaker 1: apossum has a forked penis, but it's not meant for
Speaker 1: the female's nostrils. Female apossums have a double vagina and
Speaker 1: twin uteri. Apostsum embryos developed for about thirteen days until
Speaker 1: they're large enough to migrate down the birth canal and
Speaker 1: emerge about the size of house flies to continue developing
Speaker 1: in the mother's pouch. Although dozens of them will be born,
Speaker 1: the mother only has thirteen teats, so that's probably how
Speaker 1: many will be able to survive into adulthood. Today's episode
Speaker 1: was written by Jescelyin Shields and produced by Tyler Clang.
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