The heat rushed at us as we stepped off the trail on the outskirts of Oliver, British Columbia. Grasses brushed our legs, thistles tore at our ankles, and Red-wing Blackbirds kamikazeed on the hot wind. A few dozen steps and we were at the pond. Horsetails feathered the edges and reeds struggled up from a surface constellated by water striders and boatmen. Above the water, Green Darners enforced a no-fly zone for other unlucky insects.
Despite this bucolic industry, the shallow pool - small enough to spit across - seemed completely out of place in the middle of a flat, dry field. And it was: Sara Ashpole put it there.
"This is the floodplain of the Okanagan River," she said, gesturing broadly. "At one time it was dotted with ponds and marshes and other wetlands. All gone now."
When I began investigating threats to British Columbia's amphibians, Ashpole was one of a handful of dedicated scientists labouring to save the province's disappearing frogs and salamanders - a race against time set with more hurdles than a steeplechase.
Backed by the World Wildlife Fund, Habitat Stewardship Program of Environment Canada, and Ducks Unlimited, Ashpole and crew had engineered 13 ponds as part of a program to restore habitat for the south Okanagan's beleaguered amphibians. Here, in Canada's only Bunchgrass Bioclimatic Zone (a fancy term for desert), some 85 per cent of natural wetlands had been lost to burgeoning urban and agricultural development. Of the remainder, many were already compromised by invasive species and chemicals - a disastrous situation for amphibians reliant on wetlands for breeding. The Northern Leopard Frog ( Rana pipiens ), denizen of the once-widespread marshes ringing the lakes, was long gone. The Columbia Spotted Frog ( Rana luteiventris ) - always uncommon in dry environments because of its need for permanent water - was a scattered phantom. And the rare Tiger Salamander ( Ambystoma tigrinum ) was down to but a single known breeding site.
Loss of wetlands was only one problem facing B.C.'s frogs. And the south Okanagan was a microcosm of all the top conservation threats contributing to a dramatic, worldwide decline in amphibians in recent decades: rampant habitat loss, pollution, invasive species, and emerging pathogens such as the deadly chytrid fungus (see sidebar: A Global Perspective). Not surprisingly, climate change was exacerbating the effects of all.
Just how serious was the situation?
"It's really bad news - so global," Darrel Frost, a pre-eminent herpetologist who manages the global Amphibian Species Database out of New York's American Museum of Natural History told me that summer. "Entire families disappearing. The first tropical frog I collected was a [member of genus] Craugaster . The entire genus - 30 species - is almost gone now."