He knows the stained skunks, “the acrobats of the skunk world.” According to new research, scientists have discovered that there are more of these species than they thought.
Most recently, the agreed number was four. But a new study published Wednesday in Molecular Phylogenetics and Evolution said there are seven species of spotted skunks.
“North America is one of the most studied continents in mammals, and carnivores are one of the most studied groups,” said study author Adam Ferguson, head of Negaunee’s mammal collections at the Field Museum in Negaunee. Chicago. “Everyone thinks we know all about the systematics of mammalian carnivores, so being able to redraw the skunk’s family tree is very exciting.”
Stained skunks are the smallest relatives of the common striped skunk. Approximately the size of a squirrel, these carnivorous squirrels live throughout North America. And when it comes time to scare a predator, these little guys shake hands and kick their hind legs.
“When they’re stressed, they bounce back to the forelimbs and then kick out the hind limbs, blow their tails, and in fact they can walk toward the predator, like basically making them look bigger and scarier,” Ferguson said. dit.
Skunks usually fall back to four steps in order to achieve mortality and control their stench spray. Their small height also doesn’t make these creatures retreat in combat.
Ferguson said it’s just one more example of his boldness, which he admires about skunks in general.
Although the common striped skunk has made its presence known in urban areas as well as its natural habitats, striped skunks have not made the same forays, and therefore largely remain out of sight. These “ecologically cryptic” creatures live in dense environments and remote areas and appear less adaptable to urbanization than their larger, striped counterparts, Ferguson said.
Given their agility, spotted skunks are large climbers and are much more carnivorous than other skunks, feasting on bird eggs, lizards, snakes and rodents. Great owls are their main predator.
The fact that stained skunks are so good at keeping a low profile makes them harder to study. Since the discovery of the first spotted skunk in 1758, scientists have questioned how many species exist. Over the years, differences observed between some spotted skunks led researchers to believe only two species and up to 14.
The determination that there are seven species was reduced to analyzing the genetic data of the spotted skunks. But first, Ferguson needed specimens to study. Catching the skunks is not the easiest job: Ferguson and his colleagues made six trips to Mexico while researching the stained skunks and never caught any. And if you take one out, it’s sure to spray you.
“We call it the smell of success because it means we’ve found one, which is the ultimate goal,” Ferguson said.
Ferguson was inspired to make “desired” posters and distribute them throughout central Texas to feed stores and areas where ranchers and trappers operate. The posters described the need for any stained skunk that could have been caught or found as a road kill and showed photos of the creatures. The researchers offered to come and pick up the skunk specimens and store them in a designated “skunk freezer”.
Researchers also relied on specimens from museum collections, which included stained skunks found in Central America and the Yucatan. In the end, they had 203 specimens of stained skunk to use for the study and to extract the DNA. Genetic data revealed that some of the skunks, which were previously considered the same species, were in fact very different.
“I was able to extract DNA from samples from centuries-old museums and it was really exciting to see who those individuals were related to. It turns out that one of these was an endemic species currently unrecognized in the Yucatan,” the study said. author Molly McDonough, a professor of biology at Chicago State University and a research associate at the Field Museum, in a statement.
One of the new species in the study is the spotted Yucatan skunk, which is about the size of a squirrel and is only found on the Yucatan Peninsula. Scientists also describe the spotted skunk of the plains, whose population has declined over the past century and has been suggested as an endangered species.
“The study would not have been possible without the museum specimens we had,” Ferguson said. “The only reason we got sequences from the Yucatan were museum specimens that were collected 60 or 70 years ago.”
Understanding individual species of skunks can help scientists learn more about something unique about these creatures: their reproductive biology. Spotted skunks can reproduce in the fall, but do not give birth until spring. In other words, their reproductive system intentionally delays the implantation of the egg into the uterus.
“It just stays in suspension for a while,” Ferguson said. “We want to know why some species have delayed implantation and others have not, and figuring out how these different species of skunks evolved can help us do that.”
Skunks have come a long way since they first appeared in the fossil record 25 million years ago, evolving and dividing into different species in response to climate change caused by the ice age.
Knowing more about stained skunks can also help protect these animals. Skunks have their own role inside the ecosystem, consuming fruit and defecating seeds that help the plants disperse, as well as taking advantage of pests and rodents from crops, Ferguson said.