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 Upcycling 'fast fashion' to reduce waste and pollution
03.04.2017 | American Chemical Society

nachricht Litter is present throughout the world’s oceans: 1,220 species affected
27.03.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

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: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>