Argentine ants spell trouble for horned lizards

[Guest guest]

thats all we have here in oakland..i've never seen a native california ant

here..only in the desert or up in the sierra..

can't wait for the fire ants to make it this far

 

USA: March 1, 2002

 

 

WASHINGTON - A pushy little illegal immigrant ant that is not even any good to

eat is not only forcing native California ants into extinction, but the popular

horned lizard too, scientists said this week.

 

 

The tiny Argentine ant has amply demonstrated that powerful things can come in

small packages, the team at the University of California San Diego found.

They are so prolific they are the No. 1 insect pests in parts of California.

Now, it turns out, they have replaced larger ants that are crucial to the diet

of horned lizards.

 

The lizards " don't seem to want to eat these ants, " Ted Case, a professor of

biology who led two studies on the ants published this week, said in a

statement.

 

" Even in the laboratory, when we feed them Argentine ants and nothing else, the

growing lizards can't maintain their weight. They're not getting enough

nutrition. "

 

The Argentine ants may cause other problems to the ecosystem eventually, the

researchers said. Many plants rely on the larger native ants to disperse their

seeds, and the little Argentine ants do not do that.

 

Horned lizards, also known as horned toads or horny toads, were once a staple

plaything for children in southern California, who used to catch them in dry

riverbeds.

 

" Even in back yards they are easy to catch. They are neat looking. They have

even been known to squirt blood from their eyes, " Andrew Suarez, formerly of

UCSD and now of the University of California Berkeley, said in a telephone

interview.

 

" They look like little dinosaurs. I think that what makes them so popular with

kids. "

 

The " horny toads " were hit first by habitat loss, and then by the greedy little

Argentine ants, the researchers wrote in the journals Conservation Biology and

Ecological Applications.

 

" The problem is, even in the remaining habitat we are setting aside for these

lizards, these exotic species are marching in and taking their food, " Suarez

said.

 

HORNY TOADS A CHARISMATIC SPECIES

 

Robert Fisher, a zoologist at the U.S. Geological Survey's Western Ecological

Research Center in San Diego, who worked on one of the studies, said the lizards

have been designated a " species of concern " in California. " Horned lizards may

be one of the few 'charismatic' reptiles people might care about in California, "

Fisher added.

 

The dark-brown and black Argentine ants, which are less than a tenth of an inch

(2 mm) long, probably entered the United States on ships carrying coffee or

sugar from Argentina in the 1890s.

 

Suarez said he and colleagues found a few years ago that in the United States

they form huge supercolonies of closely related ants that can beat up on other

species.

 

" In areas where they invade, the total numbers of invasive species are sometimes

10 times greater than all the native ants combined. They are really able to grow

these huge numbers of individuals and then just throw them at the native ants, "

Suarez said.

 

They have expanded throughout California and the southern United States. In much

of the South, their proliferation is limited to some extent by fire ants,

another alien species.

 

Suarez said the ants are not nearly so dominant in Argentina.

 

But they are not unbeatable. " The Argentine ants also influence the abundance of

other arthropods that live on the ground and are prey to insectivorous birds and

rodents, " Case said.

 

 

 

Story by Maggie Fox, Health and Science Correspondent

 

 

REUTERS NEWS SERVICE