Scientists concerned about beetles' effect on rare bird

September 7, 2016 by Susan Montoya Bryan

It was a good plan: Bring in hungry beetles that feed only on nonnative salt cedar trees to get a handle on a hardy, invasive species that was crowding riverbanks across the West and leaching precious water from the drought-stricken region.

The beetles have been so successful in recent years that scientists are now concerned about the fate of an endangered songbird that lives along rivers and streams in several states.

A recent U.S. Geological Survey report provides more detail about across the entire range of the Southwestern willow flycatcher. Using satellite modeling for the first time, the agency partnered with other federal scientists to predict new threats that could hamper the bird's recovery over the next decade.

By predicting the effects of tamarisk leaf beetles on the bird's habitat, the scientists hope satellite modeling can be used by land, water and wildlife managers as they try to balance protecting the bird with controlling the trees.

"Using this technology to evaluate how leaf beetle may affect flycatchers and its habitat across its range is a tremendous step forward in our understanding," said Greg Beatty, a biologist with the U.S. Fish and Wildlife Service.

Research shows the bird has become accustomed to building nests in salt cedar trees during breeding season; flycatchers are known to be picky about where they set up residence. Depending on the timing, beetles feasting on the foliage can leave baby birds exposed to higher temperatures and predators.

Beetles were released along the Pecos River in New Mexico in 2002 as a biological control for salt cedar. They're now found from Utah to Texas.

The USGS study shows they chewed through 94 percent of the flycatcher's habitat along the lower Virgin River between 2010 and 2015.

The modeling predicts about one-third of the bird's habitat along the lower Colorado River and more than half on the upper Gila River will be destroyed by beetles in the next decade.

Scientists also used the modeling to examine how the quantity of flycatcher habitat is affected annually by drought.

As a result of dry conditions, report author and USGS research biogeographer James Hatten said habitat declined in California from 2013 to 2015. New Mexico and Texas, which have rebounded from severe drought in recent years, showed increased habitat.

Government agencies and private organizations have been trying to remove tamarisk and plant native vegetation to counter the effects of beetles on flycatcher habitat. Officials say they're unsure how effective the actions will be but that the satellite model will provide a head start by identifying habitat most at risk from the beetle.

Dave Thompson, an associate dean and director of the Agriculture Experiment Station at New Mexico State University, said beetle movement around New Mexico has been significant in just the last two years as the insects have left behind dying stands of .

Thompson, an entomologist who worked on the initial beetle releases 15 years ago, said he'll be interested in how the flycatcher—an insect eater—adapts to the growing beetle population.

"The majority of our discussion about the flycatcher, as it is with other endangered species, is 'what if?' We do not want to impact them at all, but now there's a massive field experiment going on that will give us some very good data," he said.

Explore further: Beetle may pack a big punch in curbing salt cedar

Related Stories

Beetle may pack a big punch in curbing salt cedar

April 1, 2011

( -- Non-native vegetation’s infiltration to the greater Southwest has caused its share of ecosystem concerns over the years. Now Heather Bateman is looking at the effectiveness of some of the methods employed ...

Q&A: Southwest struggles to stem fire-fueling invasive plant

August 21, 2015

The tiny seedling was brought over from Eastern Europe and parts of Asia nearly 200 years ago and planted along riverbanks across the United States, mostly in the Southwest, to prevent erosion. It grew fast, its thick branches ...

Habitat needs of nestling and fledgling songbirds

July 20, 2016

Both before and after they leave the nest, baby birds face a host of challenges. A new study in The Condor: Ornithological Applications examining songbird survival in the nestling and fledgling stages finds that even in the ...

Tamarisk biocontrol efforts get evolutionary boost

July 12, 2012

UC Santa Barbara scientists trying to control the invasive tamarisk plant have been getting a boost from evolution, in the form of a rapidly evolving beetle that has been changing its life cycle to more efficiently consume ...

Recommended for you

Researchers come face to face with huge great white shark

January 18, 2019

Two shark researchers who came face to face with what could be one of the largest great whites ever recorded are using their encounter as an opportunity to push for legislation that would protect sharks in Hawaii.

Why do Hydra end up with just a single head?

January 18, 2019

Often considered immortal, the freshwater Hydra can regenerate any part of its body, a trait discovered by the Geneva naturalist Abraham Trembley nearly 300 years ago. Any fragment of its body containing a few thousands cells ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

not rated yet Sep 07, 2016
USGS - the word is Australia. Have you heard of that place?

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.