Jeepers peepers

It was just before dark on Feb. 27 when the four hunters set out. As they approached the banks of Clabber Creek in Fayetteville, they stopped, cupped their hands over their ears and listened. Traffic noise from Interstate 49 at Garland Avenue filled the air.

But through the roar ... "Peep peep! Peep peep!"

Spring peeper frogs were in the house -- or rather, in the creek.

Members of the Northwest Arkansas and North Central Arkansas FrogWatch chapters weren't looking for their next meal. Part of FrogWatch USA, sponsored by the Association of Zoos and Aquariums, members are trained to identify calls of the 23 species of frogs found in Arkansas.

The frog lovers on this hike would be happy with any frog they heard or saw, but they had a specific goal. They were looking for the "elusive" crawfish frog with a call sounding like a "snore."

"I've never heard one," said Tom Krohn, Arkansas regional coordinator for FrogWatch USA, who lives south of Yellville on the Buffalo River. But a University of Arkansas student had recorded them calling in numbers west of the campus in previous years.

As the frog watchers approached the creek, Tom Krohn pointed his light to the creek bank where it met the water, looking for egg sacks or frogs.

"There's one," Krohn said at the second stop along the creek. He grabbed at the frog all but hidden in the mud three times before he was able to pluck him out of the water and hold the amphibian in his flat hand for a few pictures. "It's the right size for a spring peeper," he noted. "It's bigger than a crawfish frog."

This peeper was the only frog found that night. Although with another three minutes holding their hands cupped to their ears, the members heard the sound of a finger running across a plastic comb -- the call of a few Cajun chorus frogs. "They're about 50 yards away (on the other side of the creek)," Krohn estimated.

At the site, Krohn posited that the temperatures might have influenced most frogs to stay buried. Although this night's predicted low temperature was near 60 degrees, previous nights had been chilly. And the forecast called for more cold nights with temperatures below freezing.

FrogWatch members across the country record the number and types of frogs heard calling from February through August. They are trained to identify the calls of frog species with habitats in their parts of the country; Arkansas is home to 23.

This citizen-science project aims to build a database to measure frog populations. These amphibians face threats through habitat destruction, pollution and pesticides, global warming, infectious diseases (spread by humans), over-harvesting for the pet and food trades and invasive species, according to Save the Frogs!, an international, nonprofit amphibian conservation organization.

"Frogs are important," reads a postcard from savethefrogs.com. "Frogs are an integral part of the food web. Frogs are bioindicators. Frogs eat ticks, mosquitos and other disease vectors. Frogs are used in medical research that benefits humans. Frogs are cool!"

BIODIVERSE LANDSCAPE

The crawfish frog remained elusive.

Krohn cited the cold temperatures as a reason, but also noted habitat destruction might affect the local populations of frog species.

The frog hunters hunted at Wilson Springs Preserve, a wetland prairie at the headwaters of Clabber Creek, owned by the Northwest Arkansas Land Trust, which works to restore and protect the habitat into perpetuity. "The 121-acre preserve is the largest wetland remnant in Fayetteville and one of the last tall grass prairies in the region," according to the trust's website.

"We face some challenges for the survival of the habitat," admitted Sim Barrow, communication and development director for the land trust. "We are in the process to restore the property."

Located in an urban environment, threats often come from invasive species (such as brush honeysuckle and Bradford pear trees) and trash, he said. "We lean on our volunteers to help out and clear the brush and trash."

And construction to widen Interstate 49 continues just a few hundred yards from the site. "We work as much as we can with the Arkansas Highway and Transportation Department to mitigate the impacts of road construction," Barrow said.

The runoff of silt from the construction can threaten the health of the stream and the Arkansas darter fish -- a candidate for the endangered species list -- that lives there. The darter is the main focus of the land trust's efforts, "but the environment that benefits the darter also benefits a whole suite of wetland-specific species," Barrow said.

The biodiversity in an environment produces direct benefits for the creatures that live there and indirect benefits for the people.

"A biodiverse ecosystem is one with lots of plants, animals, insects and amphibians that are robust enough to be able to withstand changes," Barrow explained. "We have a lot of change in Northwest Arkansas because of our growth and economic development. Lots of biodiversity means we can adapt more effectively to change."

Wetlands filter pollution and sediment out of the water, which ultimately affects the quality of drinking water of the humans living in Northwest Arkansas, Barrow continued. Also, diverse natural enviroments offer humans the opportunity to enjoy nature -- such as bird watching or going on a frog calling hike.

"It will be really exciting with so many different frog species calling in April and May," he concluded.

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Tom Krohn offers "a great case for working to protect biodiversity," Barrow said.

Krohn presents "The Sixth Mass Extinction" tonight at the Shiloh Museum of Ozark History in Springdale. His talk is sponsored by the Buffalo National River Partners.

"Mass extinctions -- when at least half of all species die out in a relatively short time -- have happened only a handful of times over the course of our planet's history," reads the website of the American Museum of Natural History in New York.

"There have been five mass extinctions in the last 500 million years -- the last one being the K-T (Cretaceious-tertiary) extinction 65 million years ago that wiped out the dinsaurs," Krohn wrote in support of his program. "Most biologists think we are in the midst of the sixth mass extinction that could wipe out over half of all existing plant and animal species by 2100."

"Typically, [the world] loses a species every 250 years," Krohn said. "But we've lost more than 300 over the last decade. That's 1,000 to 1,500 times faster. Kids born today could lose half of all living species by the end of the century."

Almost all populations are decreasing, Krohn said, sharing a frog story as an example. When Krohn was 15 years old, he acquired a license that allowed him to gig 18 bullfrogs a day. "Twenty, 40 years ago, that was no problem," he said. "You'd be lucky today to find 18 bullfrogs a month because of the loss of habitat."

According to Save the Frogs!, 2,000 amphibian species are threatened with extinction and might not survive the 21st century, and 200 amphibian species have gone extinct since 1979.

"Species go extinct all the time," the Natural History Museum website continues. "Scientists estimate that at least 99.9 percent of all species of plants and animals that ever lived are now extinct. So the demise of dinosaurs like T. rex and Triceratops some 65 million years ago wouldn't be especially noteworthy -- except for the fact that around 50 percent of all plants and animals alive at the same time also died out in what scientists call a mass extinction."

Krohn spent a career teaching math and green building techniques at colleges in Florida and Arkansas. For his presentations, he calls on information in the books Future of Life by Edward O. Wilson (Vintage, 2013) and The Sixth Extinction: An Unatural History by Elizabeth Kolbert (Picador, 2015), both of which recount case studies to present their evidence.

Krohn will discuss each of the five extinctions, including the Ordovician-silurain extinction. "Three-quarters of life on earth lived mostly in the ocean 440 million years ago." Krohn said. "The extinction wiping out that life happened over 25 million years, and it wasn't a single event. "

The shortest time frame for an extinction was 15 million years, the Permian-triassic extinction 250 million years ago, Krohn said. Mutliple volcanic eruptions in Siberia buried the earth in magma 4 miles deep, covering an area the size of the United States. The ensuing fires and the greenhouse effect triggered by the sudden release of methane from the sea floor might have caused the extinction.

"Ninety-five percent of life on earth was killed," Krohn said. "We are the descendants of that 4 percent that survived."

The dinosaurs went extinct 65 million years ago. Scientist believe the event was started by a meteor crashing into Mexico, but the die-off still took 2 million years, Krohn added.

"The current extinction was started by mankind when they started migrating out of Africa to the U.S.," Krohn continued. Societies over-hunted species like the mammoth and the buffalo, then followed the animal populations as they looked for food. The Industrial Revolution and burning of fossil fuels increased the speed of this extinction, he said.

"Unlike past mass extinctions, caused by events like asteroid strikes, volcanic eruptions and natural climate shifts, the current crisis is almost entirely caused by us -- humans," acccording to the Center for Biological Diversity. "In fact, 99 percent of currently threatened species are at risk from human activities -- primarily those driving habitat loss, introduction of exotic species and global warming. Because the rate of change in our biosphere is increasing, and because every species' extinction potentially leads to the extinction of others bound to that species in a complex ecological web, numbers of extinctions are likely to snowball in the coming decades as ecosystems unravel."

The center listed on its website the woodland bison, Merriam's elk, the Rocky Mountain grasshopper, passenger pigeons and Puerto Rico's Culebra parrot, as extinct species in human time.

"But this doesn't account for thousands of species that disappeared before scientists had a chance to describe them," the website reads. "Nobody really knows how many species are in danger of becoming extinct.

"Noted conservation scientist David Wilcove estimates that there are 14,000 to 35,000 endangered species in the United States, which is 7 to 18 percent of U.S. flora and fauna. The [International Union for Conservation of Nature] has assessed roughly 3 percent of described species and identified 16,928 species worldwide as being threatened with extinction, or roughly 38 percent of those assessed."

"But we can change that," Krohn said. "We tend to think it's 'us' versus 'them,' like nature is something separate. But we are essentially linked.

"We hope the government and scientists and technicians in the private sector can solve it," Krohn continued. "But our attitude is 'What can I do about it?' We need to think about what we can do about it as individuals."

"Without plants and animals there's not going to be any humans," Krohn said. "At least it will be the end of life as we know it."

NAN Our Town on 03/16/2017