Featured Research

from universities, journals, and other organizations

Invasive plant protects Australian lizards from invasive toad

Date:
February 22, 2012
Source:
University of Chicago Press Journals
Summary:
An invasive plant may have saved an iconic Australian lizard species from death at the hands of toxic cane toads, according to new research. It's an interesting case of one invasive species preparing local predators for the arrival of another, says a biologist involved in the research.

Bluetongue lizards from tropical Australia like the Darwin specimen to the left die if they eat an invasive cane toad, whereas members of the same lizard species from southern Australia like the Sydney specimen to the right are very resistant to the toad's poison. That tolerance seems to be due to rapid evolution brought about by the presence of a toxic garden plant that has almost identical poisons to cane toads.
Credit: Right: Travis Child Left: Sylvan Dubey

An invasive plant may have saved an iconic Australian lizard species from death at the hands of toxic cane toads, according to research published in the March issue of The American Naturalist. It's an interesting case of one invasive species preparing local predators for the arrival of another, says Richard Shine, a biologist at the University of Sydney who led the research.

Cane toads were introduced in Australia in the 1930s to control beetles that destroy sugar cane crops, but the toads quickly became an ecological disaster of their own. They produce toxins called bufadienolides, which have proven deadly to many native Australian species that feed on frogs and toads.

Bluetongue lizards are one of the vulnerable species, and their numbers began to shrink significantly after the toads arrived in northern Australia. But there's reason to believe that bluetongue populations elsewhere Australia will fare better as the toads spread across the continent.

"Our study was stimulated by a puzzling observation that arose during research on the ecological impacts of invasive cane toads … in Australia," Shine and his colleagues write. "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."

Why would these populations have evolved a tolerance to the toad toxin when no toads were present?

The answer, according to Shine and his colleagues, is likely an invasive plant species known as mother-of-millions, which happens to produce a toxin that's virtually identical to that of the cane toad. After it was imported from Madagascar as a decorative plant some 70 years ago, mother-of-millions has since run amok in parts of Queensland and New South Whales and become part of the diet for local bluetongues.

Shine and his colleagues collected bluetongues from places with and without mother-of-millions, and injected each of them with a tiny amount of cane toad toxin. They found that toads from places where mother-of-millions is common had less of a reaction than those from places where it was absent. The results suggest that 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."

The Australian government has spent millions trying to deal with the toads and mitigate their ecological impact, but Shine's work suggests the eastern bluetongues might not need much help.

"We're now able to focus our conservation dollars on those populations that can't care for themselves," he said.


Story Source:

The above story is based on materials provided by University of Chicago Press Journals. Note: Materials may be edited for content and length.


Journal Reference:

  1. Samantha J. Price-Rees, Gregory P. Brown, Richard Shine. Interacting Impacts of Invasive Plants and Invasive Toads on Native Lizards. The American Naturalist, 2012; 179 (3): 413 DOI: 10.1086/664184

Cite This Page:

University of Chicago Press Journals. "Invasive plant protects Australian lizards from invasive toad." ScienceDaily. ScienceDaily, 22 February 2012. <www.sciencedaily.com/releases/2012/02/120222132936.htm>.
University of Chicago Press Journals. (2012, February 22). Invasive plant protects Australian lizards from invasive toad. ScienceDaily. Retrieved September 2, 2014 from www.sciencedaily.com/releases/2012/02/120222132936.htm
University of Chicago Press Journals. "Invasive plant protects Australian lizards from invasive toad." ScienceDaily. www.sciencedaily.com/releases/2012/02/120222132936.htm (accessed September 2, 2014).

Share This




More Plants & Animals News

Tuesday, September 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Snack Attack: Study Says Action Movies Make You Snack More

Snack Attack: Study Says Action Movies Make You Snack More

Newsy (Sep. 2, 2014) — You're more likely to gain weight while watching action flicks than you are watching other types of programming, says a new study published in JAMA. Video provided by Newsy
Powered by NewsLook.com
Get A Mortgage, Receive A Cat — Only In Russia

Get A Mortgage, Receive A Cat — Only In Russia

Newsy (Sep. 2, 2014) — The incentive is in keeping with a Russian superstition that it's good luck for a cat to be the first to cross the threshold of a new home. Video provided by Newsy
Powered by NewsLook.com
U.N. Says Ebola Travel Restrictions Will Cause Food Shortage

U.N. Says Ebola Travel Restrictions Will Cause Food Shortage

Newsy (Sep. 2, 2014) — The U.N. says the problem is two-fold — quarantine zones and travel restrictions are limiting the movement of both people and food. Video provided by Newsy
Powered by NewsLook.com
Sharks Off the Menu and on the Tourist Trail in Palau

Sharks Off the Menu and on the Tourist Trail in Palau

AFP (Sep. 2, 2014) — Tourists in Palau clamour to dive with sharks thanks to a pioneering conservation initiative -- as the island nation plans to completely ban commercial fishing in its vast ocean territory. 01:15 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins