National Geographic : 2018 Jul
EXPLORE | BASIC INSTINCTS THE MAMMAL LINEAGE of Xenarthra—sloths, anteaters, and armadillos—has inhabited the Western Hemisphere since Paleocene times, some 65 million years ago. Clearly, they’ve been perpet- uating their species, but scientists rarely catch them in the act. Brazilian ecologist Nina Attias has. She’s spent years studying three of the 20 species of armadillos. Her doctoral research focused on Euphractus sexcinctus, aka the yellow, or six-banded, armadillo (below), whose courtship rituals she has observed and filmed. In the Pantanal wetlands of Brazil, yellow armadillo amour blooms year-round. When males catch the scent of a female in estrus, they approach, and “she just starts running,” Attias says. “You’ll see a female running like crazy and a bunch of males chas- ing her.” Once a swift suitor manages to mount the female, “coitus actually happens while they’re running,” Attias says. Even as other males chase them, the couple stays coupled. It helps that among mammals, armadillos have one of the largest penises relative to body size; an E. sexcinctus male may have a 13-inch-long body and a six-inch-long penis. And if on-the-run sex succeeds, 60 to 65 days later the female may bear one or two pups. Just procreating won’t ensure armadillos’ survival; they need human help. Brazil has a national plan for conserving three-banded armadillos. The state of Piauí has set aside parkland with the ani- mals’ protection in mind. And with support from the Institute for the Conservation of Wild Animals, where Attias works, the state of Mato Grosso do Sul plans to track giant armadillos as an indicator species, whose presence will help measure the success of habitat conservation efforts. —PATRICIA EDMONDS Know Your Armadillos 1. THREE-BANDED Only two armadillo species, the southern three-banded and the Brazilian three- banded, roll into a ball if threatened. The International Union for the Conservation of Nature assesses the Brazil- ian (Tolypeutes tricinctus) as vulnerable, and the southern (T. matacus) as near threat- ened, chiefly due to habitat loss and hunting. 2. NINE-BANDED The armorlike carapace of Dasypus novemcinctus may actually have up to 11 bands, bony plates connected by flexible tissue. The only arma- dillo whose ranks seem to be increasing, it also has the larg- est range—in South, Central, and North America—which is expanding as climates warm. 3. GIANT Found across South America, Priodontes maximus, the largest armadillo, can exceed five feet long and 110 pounds. The IUCN assesses the species as vulnerable. Indigenous peoples hunt it for meat, and some local farmers kill it because of a myth that says seeing one brings bad luck. THE JOY OF THE CHASE— OR SEX AT HIGH SPEEDS PHOTOGRAPH BY JOEL SARTORE These yellow armadillos were photographed at the National Mississippi River Museum & Aquarium, Dubuque, Iowa.