Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Rodent Robbers Good for Tropical Trees

17.07.2012
There’s no honor among thieves when it comes to rodent robbers—which turns out to be a good thing for tropical trees that depend on animals to spread their seeds.

Results of a yearlong study in Panama, published online in Proceedings of the National Academy of Sciences the week of July 16, suggest that thieving rodents helped the black palm tree survive by taking over the seed-spreading role of the mighty mastodon and other extinct elephant-like creatures that are thought to have eaten these large seeds.

“The question is how this tree managed to survive for 10,000 years if its seed dispersers are extinct,” says Roland Kays, a zoologist with North Carolina State University and the North Carolina Museum of Natural Sciences. “There’s always been this mystery of how does this tree survive, and now we have a possible answer for it.”

The study showed that agoutis, rainforest rodents that hoard seeds like squirrels, repeatedly stole from their neighbors’ underground seed caches. All that pilfering moved some black palm seeds far enough from the mother tree to create favorable conditions for germination.

“We knew that these rodents would bury the seeds but we had no idea that there would be this constant digging up of the seed, moving it and burying it, over and over again,” says Kays, a member of the Smithsonian Tropical Research Institute team. “As rodents steal the same seed many, many times, it adds up to a long-distance movement of the seed that one animal by itself could have never done.”

One seed was buried 36 times before an agouti dug it up and ate it. About 14 percent of the seeds survived until the following year.

The study, funded with a National Science Foundation grant, caught the furry thieves in the act via individual tags on agoutis, video surveillance of seed caches and tiny motion-activated transmitters attached to more than 400 seeds.

Applying such sophisticated animal tracking techniques to the plant world has the potential to improve scientists’ understanding of forest ecology and regeneration, Kays says.

“When you think about global climate change and habitats shifting, for a forest to move into new areas, trees need to have their seeds moved into new areas. This opens up a route to study how animals can help trees adjust to climate change through seed dispersal.”

Kays, a faculty member with NC State’s College of Natural Resources, was part of an international team that included scientists from Ohio State University and institutions in the Netherlands, Belgium, the United Kingdom and Germany.

Note to editors: An abstract of the paper follows.

“Thieving Rodents as Substitute Dispersers of Megafaunal Seeds”
Authors: Patrick A. Jansen, Smithsonian Tropical Research Institute, Centre for Ecosystem Studies -Wageningen University, Center for Ecological and Evolutionary Studies-University of Groningen; Ben T. Hirsch, Smithsonian Tropical Research Institute, School of Environment and Natural Resources-Ohio State University; Willem-Jan Emsens, Centre for Ecosystem Studies-Wageningen University, Ecosystem Management Research Group-Department of Biology-University of Antwerp; Veronica Zamora-Gutierrez, Centre for Ecosystem Studies-Wageningen University, Department of Zoology, University of Cambridge; Martin Wikelski, Smithsonian Tropical Research Institute, Max Planck Institute for Ornithology; Roland W. Kays, Smithsonian Tropical Research Institute, North Carolina Museum of Natural Sciences, North Carolina State University

Published: Online the week of July 16, 2012, in Proceedings of the National Academy of Sciences

Abstract: The Neotropics have many plant species that seem to be adapted for seed dispersal by megafauna that went extinct in the late Pleistocene. Given the crucial importance of seed dispersal for plant persistence, it remains a mystery how these plants have survived more than 10,000 years without their mutualist dispersers. Here we present support for the hypothesis that secondary seed dispersal by scatterhoarding rodents has facilitated the persistence of these largeseeded species. We used miniature radio transmitters to track the dispersal of reputedly megafaunal seeds by Central American agoutis, which scatter-hoard seeds in shallow caches in the soil throughout the forest. We found that seeds were initially cached at mostly short distances and then quickly dug up again. However, rather than eating the recovered seeds, agoutis continued to move and recache the seeds, up to 36 times. Agoutis dispersed an estimated 35 percent of seeds for >100 m. An estimated 14 percent of the cached seeds survived to the next year, when a new fruit crop became available to the rodents. Serial video-monitoring of cached seeds revealed that the stepwise dispersal was caused by agoutis repeatedly stealing and recaching each other’s buried seeds. Although previous studies suggest that rodents are poor dispersers, we demonstrate that communities of rodents can in fact provide highly effective long-distance seed dispersal. Our findings suggest that thieving scatter-hoarding rodents could substitute for extinct megafaunal seed dispersers of tropical large-seeded trees.

Dr. Roland Kays, roland_kays@ncsu.edu or via Skype at roland.kays
D’Lyn Ford, News Services, 919/513-4798 or 919/480-9493 and dlyn_ford@ncsu.edu

D’Lyn Ford | Newswise Science News
Further information:
http://www.ncsu.edu

More articles from Life Sciences:

nachricht New risk factors for anxiety disorders
24.02.2017 | Julius-Maximilians-Universität Würzburg

nachricht Stingless bees have their nests protected by soldiers
24.02.2017 | Johannes Gutenberg-Universität Mainz

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>