Nearly extinct spray toads – 03/26/2004

  • September 30, 2013 at 5:50 pm #398
    By Jenni Laidman

    A tiny toad nearing extinction in the wild is making its last stand at
    the Toledo Zoo.

    In a closet-sized room in the reptile house, keeper Tim Herman tends
    a makeshift cloud forest. His charges chirp happily as a steady mist
    spritzes their verdant homes.

    These 24 Kihansi spray toads are the survivors, nearly the last of
    their kind. In January, a trip to their natal territory along the
    Kihansi River in Tanzania revealed the truth. From the tens of
    thousands first discovered in 1996, researchers found five.

    “We saw one very skinny male, two females, and I heard two other
    males calling,” said Sam Lee, of the Wildlife Conservation Society in
    New York.

    Toledo Zoo is now home to one-third of the world’s captive
    population. The other 50 captive toads soon will be at the Wildlife
    Conservation Society, the former Bronx Zoo. These two captive
    populations are the remnants of an ambitious restoration program now
    barely hanging on.

    “We might have avoided some of this if things were planned a little
    better in the beginning,” Lee said. Lack of support for the breeding
    program at the start may condemn this last effort, he said.

    It began in 2000, when zoos in Detroit and New York received a total
    of 538 toads from Tanzania. They hoped to establish a breeding
    population that could one day return toads to the wild.

    Tanzania is a hard-pressed country. Its people are poor. The Kihansi
    River, with its 260-foot-high waterfalls and its torrent of water,
    was a natural resource. Damming it would provide electricity and,
    perhaps, prosperity.

    In 2000, with a sizeable World Bank loan, the river was dammed and
    its flow diverted. Now a trickle of water drips into the gorge that
    was home to thousands of spray toads.

    The animals had lived in a tiny paradise, their entire equatorial
    existence a gift of the mist rising from the cataract. Perfectly
    adapted for this small niche, the toads were devastated when it was
    cut off. They crowded along the edge of the river, surviving on the
    thinnest slice of their territory.

    To save this remnant, narrow pipes sprayed the toad habitat with
    water. It worked for awhile. Toad numbers rose from a low of 2,000 to
    as many as 17,000 in 2003. Then disaster struck. A fungus that has
    slaughtered frogs around the globe invaded the Kihansi.

    Meanwhile, the captive toads were dying too. They came from the wild
    with lungworms. Half the founding population died before
    veterinarians gained control.

    Despite this, the animals bred vigorously. Nearly 700 were born at
    the Bronx Zoo. Toads were shipped to other zoos. The Toledo Zoo,
    along with zoos in Oklahoma City, Baltimore and Buffalo, each
    received spray toads, but most of those died off.

    Toledo has seen at least some success. First, there was dumb luck,
    Herman said. In looking for plants to carpet toad homes, he stumbled
    on the exact species of club moss the animals live with in Africa.

    Then, there was success born of Herman’s determination, said R.
    Andrew Odum, Toledo Zoo’s reptile curator.

    Looking at the skinny, fragile toads, Herman surmised the animals
    weren’t getting the right light. Without proper ultraviolet light,
    the animals cannot metabolize calcium. In an extensive search, he
    sussed out the right bulb.

    A World Bank representative said the institution plans to cover
    captive breeding costs at the zoos for at least six months, and
    possibly longer.

    But even if money is forthcoming, success is far from assured, Lee

    “This is our last-ditch effort. This is our Alamo. It’s a little too
    late, basically, or maybe a lot too late.”

    (bill in boston)

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