Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Fragmentation may be linked to local amphibian extinctions

25.09.2002


Habitat fragmentation is a primary threat to amphibians worldwide, and new research suggests one of the reasons why. Experimental evidence for three species shows that fragmentation may hinder the dispersal of juvenile amphibians, which could contribute to population declines.



"Habitat fragmentation is likely to reduce dispersal rates between local populations of these three species," say Betsie Rothermel and Raymond Semlitsch of the University of Missouri in Columbia in the October issue of Conservation Biology.

Dispersal of juvenile amphibians is critical to maintaining populations of pond-breeding species. Local populations of these amphibians naturally die out frequently but are replenished by juveniles from other ponds (adults rarely switch breeding sites). "Interpond dispersal is the means by which declining populations may be rescued or recolonized following extinction," say the researchers. However, little is known about how habitat disturbance affects the dispersal of juvenile amphibians.


Rothermel and Semlitsch studied the movements of three types of juvenile amphibians (spotted salamander, small-mouthed salamander and American toad) in the 127-ha C.W. Green Conservation Area in Boone County, Missouri. In the midwestern U.S., much of the land around amphibian breeding sites has been converted from forest to cropland or pasture. The researchers collected amphibian eggs in the wild, raised them in tanks, transferred the larvae to artificial pools on the edges between forest and old fields, and then studied their movements during the first two months after metamorphosis.

While small-mouthed salamanders showed no preference for forest or old field, the researchers found that the other two species studied moved farther into the forest than into old fields. Spotted salamanders moved almost eight times farther and toads moved more than three times farther (spotted salamanders moved 43 vs. 5 feet in the forest and old field, respectively; the toads moved 108 vs. 33 feet, respectively).

The juvenile toads’ preference for the forest came as a surprise because the species is ubiquitous, occurring in natural and disturbed habitats alike. The fact that the juvenile toads avoided the open field shows that juvenile behavior cannot be predicted based on adult behavior, say the researchers.

Rothermel and Semlitsch suggest that moving through fields would make the juvenile amphibians more vulnerable to predators or desiccation. They compared how fast juvenile salamanders desiccated in the forest and in the field, and found that in a 24-hour period they lost about a third more water in the field (6% vs. 4.5% of their body weight in the field and forest, respectively). This is not surprising because the maximum temperatures were roughly 10 degrees Celsius higher in field than in forest.

Rothermel concludes that conserving amphibian populations in highly fragmented forests may require connecting their habitat patches. "The results of this study suggest that juvenile amphibians might preferentially use corridors of natural vegetation," she says.

ADDITIONAL CONTACT INFORMATION:
*Raymond Semlitsch (573-884-6396, semlitschr@missouri.edu)

Betsie Rothermel | EurekAlert!
Further information:
http://www.biosci.missouri.edu/semlitsch/index.html
http://nasw.org/users/rmeadows
http://conservationbiology.org/

More articles from Ecology, The Environment and Conservation:

nachricht How to detect water contamination in situ?
22.09.2016 | Tomsk Polytechnic University (TPU)

nachricht Quantifying the chemical effects of air pollutants on oxidative stress and human health
12.09.2016 | Max-Planck-Institut für Chemie

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: OLED microdisplays in data glasses for improved human-machine interaction

The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.

“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...

Im Focus: Artificial Intelligence Helps in the Discovery of New Materials

With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.

Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...

Im Focus: Complex hardmetal tools out of the 3D printer

For the first time, Fraunhofer IKTS shows additively manufactured hardmetal tools at WorldPM 2016 in Hamburg. Mechanical, chemical as well as a high heat resistance and extreme hardness are required from tools that are used in mechanical and automotive engineering or in plastics and building materials industry. Researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden managed the production of complex hardmetal tools via 3D printing in a quality that are in no way inferior to conventionally produced high-performance tools.

Fraunhofer IKTS counts decades of proven expertise in the development of hardmetals. To date, reliable cutting, drilling, pressing and stamping tools made of...

Im Focus: Launch of New Industry Working Group for Process Control in Laser Material Processing

At AKL’16, the International Laser Technology Congress held in May this year, interest in the topic of process control was greater than expected. Appropriately, the event was also used to launch the Industry Working Group for Process Control in Laser Material Processing. The group provides a forum for representatives from industry and research to initiate pre-competitive projects and discuss issues such as standards, potential cost savings and feasibility.

In the age of industry 4.0, laser technology is firmly established within manufacturing. A wide variety of laser techniques – from USP ablation and additive...

Im Focus: New laser joining technologies at ‘K 2016’ trade fair

Every three years, the plastics industry gathers at K, the international trade fair for plastics and rubber in Düsseldorf. The Fraunhofer Institute for Laser Technology ILT will also be attending again and presenting many innovative technologies, such as for joining plastics and metals using ultrashort pulse lasers. From October 19 to 26, you can find the Fraunhofer ILT at the joint Fraunhofer booth SC01 in Hall 7.

K is the world’s largest trade fair for the plastics and rubber industry. As in previous years, the organizers are expecting 3,000 exhibitors and more than...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Experts from industry and academia discuss the future mobile telecommunications standard 5G

23.09.2016 | Event News

ICPE in Graz for the seventh time

20.09.2016 | Event News

Using mathematical models to understand our brain

16.09.2016 | Event News

 
Latest News

Stronger turbine blades with molybdenum silicides

26.09.2016 | Materials Sciences

Scientists Find Twisting 3-D Raceway for Electrons in Nanoscale Crystal Slices

26.09.2016 | Materials Sciences

Lowering the Heat Makes New Materials Possible While Saving Energy

26.09.2016 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>