Featured Research

from universities, journals, and other organizations

Global Warming Is Killing Frogs And Salamanders In Yellowstone Park, Researchers Say

Date:
October 29, 2008
Source:
Stanford University
Summary:
Frogs and salamanders, those amphibious bellwethers of environmental danger, are being killed in Yellowstone National Park. The predator, Stanford researchers say, is global warming. One biology graduate student spent three summers in a remote area of the park searching for frogs and salamanders in ponds that had been surveyed 15 years ago. Almost everywhere she looked, she found a catastrophic decrease in the population.

A tiger salamander (Ambystoma tigrinum) in Yellowstone.
Credit: Sarah McMenamin

Frogs and salamanders, those amphibious bellwethers of environmental danger, are being killed in Yellowstone National Park. The predator, Stanford researchers say, is global warming.

Related Articles


Biology graduate student Sarah McMenamin spent three summers in a remote area of the park searching for frogs and salamanders in ponds that had been surveyed 15 years ago. Almost everywhere she looked, she found a catastrophic decrease in the population.

The amphibians need the ponds for their young to hatch, but high temperatures and drought are drying up the water. The frogs and salamanders lay eggs that have a gelatinous outer layer—basically "jelly eggs," McMenamin says—that leaves them completely unsuitable for gestation on land. If the ponds dry up, so do the eggs. "If there isn't any water, then the animals simply don't breed," she said.

Biology Associate Professor Elizabeth Hadly, McMenamin's graduate adviser and co-author of a research paper published this week on the website of the Proceedings of the National Academy of Sciences, has worked in Yellowstone since 1981 and has witnessed the ponds going dry. "They're just blinking off," she said. "It's depressing."

"Precipitous declines of purportedly unthreatened amphibians in the world's oldest nature reserve indicate that the ecological effects of global warming are even more profound and are happening more rapidly than previously anticipated," the researchers wrote.

The disappearing ponds lie in picturesque northern Yellowstone, specifically the lower Lamar Valley, which holds dozens of small fishless ponds where the habitat has been ideal for the breeding and larval development of blotched tiger salamanders, boreal chorus frogs and Colombia spotted frogs. As the world's first national park, it is one of the most environmentally protected areas in the world.

The researchers studied climate and water records going back a century, ranging from handwritten logs of water flow in the Lamar River to satellite imagery, and could find no cause for the drying ponds other than a persistent change in temperature and precipitation. "It's the cumulative effects of climate," Hadly said.

During the summers of 2006 through 2008, McMenamin, wearing hip waders and carrying a dip net, cataloged the amphibian life—or lack thereof—in and around 42 ponds that had been surveyed in 1992-1993. In that earlier survey, involving 46 ponds, 43 supported amphibian populations for at least one of the two years. But in the recent inspection, only 38 of those same ponds even contained water in summer.

In their fieldwork, the researchers were able to visit 31 of the 38 wet ponds (the remainder were off limits, to protect nesting trumpeter swans). Only 21 of them supported amphibian populations for even one of the three years they were checked, 2006-2008. In 15 years the number of ponds with frogs and salamanders had dropped drastically.

"That's when we really got alarmed, because the data just showed such a huge difference," Hadly said.

Historically, the ponds—as small as backyard fish ponds, as large as small lakes—have been recharged during the summer by the groundwater in the soil. But the water table is dropping, the researchers say, as human-induced climate change produces a deadly combination of higher temperatures and less rain and snow. Moreover, the seasonal wetlands near the ponds, usually ideal amphibian habitat, are evaporating earlier in the spring, the result of an earlier snowmelt.

During the course of their study, the researchers witnessed the loss of four amphibian communities because of pond drying. Each event left hundreds of dried tiger salamander corpses behind. The ponds had dried rapidly, over just a few days, too fast for larvae to metamorphose and adults to migrate.

"Everybody can identify with the loss of glaciers, but in Yellowstone the decrease in lakes and ponds and wetlands has been astounding," John Varley, the former chief scientist for Yellowstone, told New West. "What were considered permanent bodies of water, meaning reference was given to them in the 1850s, '60s and '70s, and bestowed with a name as a lake, are now gone. Some wetlands that were considered permanent ponds are no longer there. Some lakes have become ephemeral."

The problem is not going to go away, McMenamin said. "It's extremely depressing and there aren't any evident solutions that come to mind. It's a symptom of a much, much larger problem."


Story Source:

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


Journal Reference:

  1. McMenamin et al. Climatic change and wetland desiccation cause amphibian decline in Yellowstone National Park. Proceedings of the National Academy of Sciences, October 27, 2008; DOI: 10.1073/pnas.0809090105

Cite This Page:

Stanford University. "Global Warming Is Killing Frogs And Salamanders In Yellowstone Park, Researchers Say." ScienceDaily. ScienceDaily, 29 October 2008. <www.sciencedaily.com/releases/2008/10/081028184830.htm>.
Stanford University. (2008, October 29). Global Warming Is Killing Frogs And Salamanders In Yellowstone Park, Researchers Say. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2008/10/081028184830.htm
Stanford University. "Global Warming Is Killing Frogs And Salamanders In Yellowstone Park, Researchers Say." ScienceDaily. www.sciencedaily.com/releases/2008/10/081028184830.htm (accessed October 25, 2014).

Share This



More Plants & Animals News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Reuters - Innovations Video Online (Oct. 24, 2014) Miniature deep sea animals discovered off the Australian coast almost three decades ago are puzzling scientists, who say the organisms have proved impossible to categorise. Academics at the Natural History of Denmark have appealed to the world scientific community for help, saying that further information on Dendrogramma enigmatica and Dendrogramma discoides could answer key evolutionary questions. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Black Bear Cub Goes Sunday Shopping

Black Bear Cub Goes Sunday Shopping

Reuters - Light News Video Online (Oct. 23, 2014) Price check on honey? Bear cub startles Oregon drugstore shoppers. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Dances With Wolves in China's Wild West

Dances With Wolves in China's Wild West

AFP (Oct. 23, 2014) One man is on a mission to boost the population of wolves in China's violence-wracked far west. The animal - symbol of the Uighur minority there - is under threat with a massive human resettlement program in the region. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
Breakfast Debate: To Eat Or Not To Eat?

Breakfast Debate: To Eat Or Not To Eat?

Newsy (Oct. 23, 2014) Conflicting studies published in the same week re-ignited the debate over whether we should be eating breakfast. Video provided by Newsy
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:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

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