When you're as rare and vulnerable as a black toad [Anaxyrus exsul], you can't afford to be coy about romance.
Surrounded by an unforgiving desert and forever isolated on a small patch of irrigated ranchland about 50 miles southeast of Yosemite National Park, black toads inhabit the smallest range of any North American amphibian.
So when breeding season arrives, as it did last month, this high desert basin nestled between the Inyo and White mountain ranges resounds with the toad's high-pitched chirrups, which are reminiscent of peeping of baby chicks.
But this "toad heaven" would not be possible without the annual cooperation of the ranch owner, Deep Springs College. One of the smallest institutions of higher education in the United States, Deep Springs provides the amorous toads with all the basic creature comforts they will need to pair up and produce new crops of eggs and tadpoles.
Among those necessary comforts are peace, quiet and plenty of room for the 2-inch-long black toads with warty skin and golden eyes to serenade each other.
Cattle are kept away from the springs that ooze from the base of a nearby cliff from March through September—ensuring that courting toads don't get trampled, said Tim Gipson, 63, ranch manager at the college.
"My priorities are cattle, toads, water and pasturelands," Gipson said. "We only graze cattle by the springs in winter, when the toads are dormant and hibernating underground."
Grazing cattle and saving black toads have been dominant forces on campus operations for half a century, and a conservation success story at a time when amphibians are facing declines and extinctions across the United States and around the world.
Once abundant across the vast floodplains of the Great Basin, only about 8,500 black toads cling to existence by their stubby little toes at the college, a relic population isolated about 12,000 years ago when things were starting to heat up.
The toad's first scientific name, Bufo exsul, acknowledges its extreme isolation. It means "exiled toad."
Greg Pauley, herpetological curator at the Natural History Museum of Los Angeles County, was a graduate student when he first ventured to Deep Valley Springs two decades ago. "It was a bit of a shock to see how desolate, isolated and critically important their habitat is," he recalled. "What's terrifying now are the increasing demands for use of the desert aquifers that sustain such sites."
Read more: https://phys.org/news/2021-04-rare-california-toads-thirsty-tiny.html
Image source: http://www.californiaherps.com/frogs/pages/a.exsul.html
