Oh 2020. You’re the gift that never stops giving … no matter how hard we beg, plead, cajole, pray or threaten. While it seems that this miserable year has brought forth every vile thing imaginable – and a few no one imagined – it hasn’t brought giant rats with poison fur … until now. While they try to win our hearts with their monogamy and good family lives, a new study found that these giants have developed a new way to kill that may inspire a new Bond villain – they lick and chew the bark of the poison arrow tree, then spit it onto their fur in quantities large enough to kill any prey … including humans. Is this your next 2020-induced nightmare?
"It's considered a 'black box' of a rodent. We initially wanted to confirm the toxin sequestration behavior was real and along the way discovered something completely unknown about social behavior. Our findings have conservation implications for this mysterious and elusive rat."
Hasn’t 2020 taught everyone not to open black boxes? In a new Journal of Mammalogy study with a deceiving reality-show name, “The secret social lives of African crested rats, Lophiomys imhausi,” Sara Weinstein, lead author and Smithsonian-Mpala postdoctoral fellow and postdoctoral researcher at the University of Utah, explains how a 2011 study of one instance of a giant African crested rat created its own poison-arrow fur inspired her and her team to head to East Africa and trap 25 of these large rodents with a crest of hair on their backs that lifts when threatened to expose body-length black and white stripes laden with the toxin.
“They're herbivores, essentially rat-shaped little cows. They spend a lot of time eating, but they walk around, mate, groom, climb up the walls, sleep in the nest box."
Measuring 21 inches (530 mm) from nose to tail, the “rat-shaped little cows” were given branches from the poison arrow tree (Acokanthera schimperi), all parts of which contain acovenoside A and ouabaïne, two toxins lethal to humans and other mammals. The herbivores took to the branches like cows on a hay bale – chewing them to a pulp but not swallowing them. Instead, they spit the poison-filled saliva onto their stripes where it would be stored until needed. The experiment proved that the African crested rats are the only mammals immune to poison arrow tree toxins and strengthened the 2011 study with a larger data set. It also had an added benefit, as Weinstein explained in the press release.
“We put these two rats together in the enclosure and they started purring and grooming each other. Which was a big surprise, since everyone we talked to thought that they were solitary. I realized that we had a chance to study their social interactions."
In multiple “Aw, isn’t that cute” moments, the researchers, using hidden video cameras, learned that the African crested rats are monogamous, showing caring touching and grooming behavior with their mates. They also resemble many human families in that their juvenile offspring stay home and are cared for by their parents long after they could venture out on their own. Finally, they heard squeaks, purrs and other noises the rats use for communications.
While other animals in the area may applaud the news, study co-author Bernard Agwanda from the National Museums Kenya concludes with the warning that the giant African crested rats are in danger of extinction due to development.
“We don't have accurate numbers, but we have inferences. There was a time in Nairobi when cars would hit them and there was roadkill everywhere. Now encountering them is difficult. Our trapping rate is low. Their population is declining."
Do we restrict development save the monogamous, poisonous-fur-loaded giant African crested rats that only their mothers love? Oh, 2020 -- you continue to present such hard choices.