Black fur, white stripes, a belly full of foul-smelling liquid – everyone can recognize the striped skunk. But did you know that these foul-smelling mammals have a number of smaller cousins, characterized by a pattern of black and white Rorschach spots? Known as the spotted skunks, they do something the Stripeys can’t.
Spotted skunks do a splayed handstand before spraying you.
“I jokingly call them the acrobats of the skunk world,” said Adam Ferguson, a petty carnivore biologist at the Field Museum in Chicago.
Now that you’ve learned about the spotted skunk, here’s another important fact: there is more than one species, and it is difficult to analyze the difference between them. For starters, the stinkbutts all look pretty similar. Most scientists today agree that there are four species of spotted skunk, although previous research has indicated only two species, or up to 14.
However, researchers have a new answer to this question that they published in the journal Molecular Phylogenetics and Evolution on Thursday. It’s based on more than 200 DNA samples from spotted skunks, some of which were killed from the street, in locations from British Columbia to Costa Rica.
“There are definitely seven types,” says Molly McDonough, a phylogenomist at Chicago State University and a research fellow at both the Field Museum and the Smithsonian’s Museum of Natural History.
Dr. McDonough and Dr. Ferguson, the co-lead authors on the new study, are also married. She calls him the skunk waster and he calls her the lab wizard. When he suggested, he even put the ring in a box of DNA preparations.
It’s the couple sprayed together, as they say, stays together.
“If you approach the skunk very quietly and gently, there will be no tendency for them to spray,” said Dr. Ferguson. “But I say skunks are like humans. Some of them are just idiots. “
While spotted skunks do everything possible to keep researchers at bay, there are several compelling reasons to study the small carnivores.
For example, now that the researchers have mapped seven different lineages for genomic similarities, they can see that the spotted skunks are much more diversified than their close relatives, the striped skunks and the pig noses (which look a bit like a skunk version). of a black and white biscuit). This is strange, and scientists suspect it has something to do with the spotted skunks being the smallest stinkers in North America.
“We assume that they are more rodent-like,” said Dr. Ferguson and was referring to the inability of the two-pound skunks to travel very far in any direction and their relatively quick breeding cycles.
These factors appear to have enabled the spotted skunks to branch out into new species over the course of the last Ice Age and its changes in the North American climate.
The researchers also found that most of the spotted skunk species could be divided into two groups, or clades, three of which were from the east and three from the west. (The seventh species of spotted skunk, Spilogale yucatanensis, is a bit strange because it is native to Mexico’s Yucatán Peninsula, but has the closest evolutionary relationship to S. putorius, which is native to Florida and the American Southeast.)
The biggest difference between the two clades is that they appear to reproduce in completely different ways. In the eastern clade, females tend to be pregnant for around 50 to 65 days, mate in March or April, and give birth in May or June. In the west, spotted skunks typically breed in the fall around September or October and then give birth in April or May for a total gestation period of 180 to 200 days.
How is that possible? There is evidence that Western skunks use a strategy known as delayed implantation, in which a fertilized egg goes into a dormant phase before development. Females of many mammal species, from bats to bears, use this practice to conserve resources and survive seasonal food shortages.
And because representatives of both clades have overlapping territories in places like Texas, you could have two spotted skunks in the same spot that appear identical but apparently cannot breed with each other because their reproductive strategies are incompatible.
So what is it like studying skunks with your significant other? Well, once upon a time in Mexico, a pig-nosed skunk had Dr. Ferguson just sprayed on his face which temporarily blinded him.
“While I was running for water, screaming, she actually asked me, ‘Will I help you or do I catch the skunk?'” He said.
Not wanting to lose the data point, Dr. McDonough the skunk.