'Dwarf' foxes, saved from extinction, make an incredible recovery

Stephen Messenger

Science / Endangered Species

May 28, 2013

While they may be a bit smaller than your average house cat, what these 'dwarf' Island foxes lack in stature, they make up for in resilience.

Not long ago, the future looked bleak for the distinctly diminutive fox species that reside on California's Channel Islands. In the mid-1990s, the island fox's numbers had plummeted from the thousands to, in some cases, just over a dozen -- raising alarms that the species would soon be extinct and prompting them to be classified as a 'critically endangered' species.

But now, after a few short years of incredibly well-executed conservation tactics, biologists say that the tiny canine has made one of the fastest recoveries of any animal in the history of the Endangered Species Act.

The history of the island fox's decline offers a lesson on the interconnectivity of nature. Bald eagles were once common along the Channel Islands, feeding mostly on fish while the foxes feasted on insects, birds, and other land mammals. Exposure to the now-banned insecticide DDT, which washed into the ocean and contaminate their diet, caused bald eagles to die off -- opening the skies over the islands for a new bird of prey to take hold.

Continued

Invasive plant saving Australian lizards (via Herp Digest)

CHICAGO, Feb. 23 (UPI) -- An Australian lizard may have been saved from extinction at the hands of invasive toxic toads by an invasive species of plant, researchers say.

Cane toads, introduced in Australia in the 1930s to control a beetle pest in sugar cane crops, quickly became an ecological disaster of their own because they produce toxins called bufadienolides, deadly to many native Australian species that feed on frogs and toads, an article in The American Naturalist reported.

Bluetongue lizards are one of the vulnerable species, but some bluetongue populations seem less vulnerable to the toxins, researchers said.

"Some lizard populations were vulnerable to bufotoxins whereas others were not -- and the populations with high tolerance to bufotoxins included some that had never been exposed to toads," researcher Richard Shine of the University of Sydney said.

The reason, Shine and his colleagues said, is likely an invasive plant species known as mother-of-millions, imported from Madagascar as an ornamental plant, that has become part of the diet of bluetongues in some regions and happens to produce a toxin that's virtually identical to that of the cane toad.

The researchers suggest the plant drove strong selection for lizards that could tolerate bufotoxins -- a remarkable example of evolution over a relatively short period of some 20 to 40 generations of lizards.

"Now it appears we have a population of eastern bluetongue lizards that are able to defend themselves well against cane toads -- even though they've never actually met one -- whereas the devastation of the cane toads on the northwestern lizard population continues," Shine said. "Eating this plant has pre-adapted the eastern blueys against cane toad poisons."

Bittern: other species that have made comeback from extinction

There have been several species that have come back from the brink of extinction. Here are some examples.

Dormice and water voles: Two of Britain's best-loved countryside mammals, are recovering from the brink of extinction thanks to conservation programmes to save them. Both animals are well known through popular fiction: the dormouse was immortalised in Alice's Adventures in Wonderland and Ratty in Wind in the Willows is a water vole. Intensive farming techniques, pollution and climate change had threatened to wipe out both species across much of England.

Bumblebees: The five most threatened bumblebees in England have made an unprecedented comeback in the South East this year thanks to environmental work by farmers. The large garden bumblebee, the shrill carder bee, the red shanked carder bee, the moss carder bee and the brown banded carder bee are all considered under threat. The species have suffered from intensive farming, that means there are less wildflowers and the spread of towns and cities.

Farmland birds: Endangered species of countryside birds are staging a dramatic comeback on farms taking part in a pioneering conservation experiment. Even fast-disappearing species such as yellowhammer and house sparrow are flourishing on the farms involved.

Grizzly bear and Grey Wolf: After being wiped out in the 1930s, the Grey Wolf's population has swelled to more than 5000 across America. The grizzly bear and the wolf could be removed from the US list of endangered species, in a move likely to spark fierce resistance from environmentalists. Previous efforts by the George W Bush administration to remove protections from the two species were defeated by opposition in court from wildlife conservation groups.

Great bustard: A bid to reintroduce the great bustard to the UK has scored another success with four wild chicks hatching in this country so far in 2010. It is the second year that the internationally endangered birds, which have been reared in captivity and released on Salisbury Plain, Wiltshire, over the past few years, have successfully bred. The large species, whose males can stand over a metre tall (40 inches) and with a wingspan of up to 2.4m (7.75 ft) had disappeared from the UK by 1832 after being hunted to extinction.

Pictures at:
http://www.telegraph.co.uk/earth/wildlife/8736663/Bittern-other-species-that-have-made-comeback-from-extinction.html