PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Rodent robbers good for tropical trees

2012-07-17
(Press-News.org) 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.



INFORMATION:

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.



ELSE PRESS RELEASES FROM THIS DATE:

Genetically engineered bacteria prevent mosquitoes from transmitting malaria

2012-07-17
Researchers at the Johns Hopkins Malaria Research Institute have genetically modified a bacterium commonly found in the mosquito's midgut and found that the parasite that causes malaria in people does not survive in mosquitoes carrying the modified bacterium. The bacterium, Pantoea agglomerans, was modified to secrete proteins toxic to the malaria parasite, but the toxins do not harm the mosquito or humans. According to a study published by PNAS, the modified bacteria were 98 percent effective in reducing the malaria parasite burden in mosquitoes. "In the past, we worked ...

To clean up the mine, let fungus reproduce

2012-07-17
Cambridge, Mass. - July 16, 2012 - Harvard-led researchers have discovered that an Ascomycete fungus that is common in polluted water produces environmentally important minerals during asexual reproduction. The key chemical in the process, superoxide, is a byproduct of fungal growth when the organism produces spores. Once released into the environment, superoxide reacts with the element manganese (Mn), producing a highly reactive mineral that aids in the cleanup of toxic metals, degrades carbon substrates, and controls the bioavailability of nutrients. The results, ...

Human cells, plants, worms and frogs share mechanism for organ placement

2012-07-17
MEDFORD/SOMERVILLE, Mass. – As organisms develop, their internal organs arrange in a consistent asymmetrical pattern--heart and stomach to the left, liver and appendix to the right. But how does this happen? Biologists at Tufts University have produced the first evidence that a class of proteins that make up a cell's skeleton -- tubulin proteins -- drives asymmetrical patterning across a broad spectrum of species, including plants, nematode worms, frogs, and human cells, at their earliest stages of development. "Understanding this mechanism offers insights important ...

New studies reveal hidden insights to help inspire vegetable love

2012-07-17
WASHINGTON, DC (July 16, 2012) -- Two new studies presented today at the Society for Nutrition Education and Behavior's (SNEB) annual conference may make it easier for moms to get their kids to eat – and enjoy – vegetables. Both studies were conducted by SNEB president Brian Wansink, PhD, the John Dyson Professor of Consumer Behavior at Cornell University, and funded by Birds Eye, the country's leading vegetable brand that recently launched a three-year campaign to inspire kids to eat more veggies. With nine out of 10 American children and teens not meeting daily vegetable ...

Hospitals in recession-hit areas see uptick in serious cases of child physical abuse

2012-07-17
In the largest study to examine the impact of the recession on child abuse, researchers at The Children's Hospital of Philadelphia's (CHOP) PolicyLab detected a significant increase in children admitted to the nation's largest children's hospitals due to serious physical abuse over the last decade. The study, published today in the journal Pediatrics, found a strong relationship between the rate of child physical abuse and local mortgage foreclosures, which have been a hallmark of the recent recession. The CHOP findings, based on data from 38 children's hospitals, contradict ...

SIgN scientists discover dendritic cells key to activating human immune responses

2012-07-17
Scientists at A*STAR's Singapore Immunology Network (SIgN), in collaboration with Newcastle University, UK, the Singapore Institute of Clinical Sciences and clinicians from multiple hospitals in Singapore, have identified a new subset of dendritic cells (DCs%r9 in human peripheral tissue which have a critical role in activating our immune response against harmful pathogens. This research will have significant impact on the design of vaccines and other targeted immunotherapies. The scientists also showed for the first time that DC subsets are conserved between species, facilitating ...

Nurses need to counteract negative stereotypes of the profession in top YouTube hits

2012-07-17
The nursing profession needs to harness the power of the video-sharing website YouTube to promote a positive image of nurses, after research found that many of the top hits portray them in a derogatory way. That is the key finding of research published in the August issue of the Journal of Advanced Nursing. Researchers examined the YouTube database to find the most viewed videos for "nurses" and "nursing". Ninety-six videos were included after preliminary analysis of the first 50 hits for each word. The top ten hits - attracting between 61,695 and 901,439 hits - were ...

Getting your message across

2012-07-17
Far from processing every word we read or hear, our brains often do not even notice key words that can change the whole meaning of a sentence, according to new research from the Economic and Social Research Council (ESRC). After a plane crash, where should the survivors be buried? If you are considering where the most appropriate burial place should be, you are not alone. Scientists have found that around half the people asked this question, answer it as if they were being asked about the victims not the survivors. Similarly, when asked "Can a man marry his widow's ...

Engineering technology reveals eating habits of giant dinosaurs

2012-07-17
High-tech technology, traditionally usually used to design racing cars and aeroplanes, has helped researchers to understand how plant-eating dinosaurs fed 150 million years ago. A team of international researchers, led by the University of Bristol and the Natural History Museum, used CT scans and biomechanical modelling to show that Diplodocus - one of the largest dinosaurs ever discovered – had a skull adapted to strip leaves from tree branches. The research is published today [16 July] in leading international natural sciences journal, Naturwissenschaften. The Diplodocus ...

Obesity may affect response to breast cancer treatment

2012-07-17
Women who are obese continue to have higher levels of oestrogen than women of normal weight even after treatment with hormone-suppressing drugs, raising the possibility that they might benefit from changes to their treatment. The study, led by a team at The Institute of Cancer Research in London and The Royal Marsden NHS Foundation Trust, found hormone-suppressing drugs did markedly reduce oestrogen levels in obese women – but that their levels of oestrogen remained more than double those of women of normal weight. The research, which is published today in the Journal ...

LAST 30 PRESS RELEASES:

ESMO 2025: VT3989 continues to show promising early results in patients with advanced mesothelioma

Study finds COVID-19 mRNA vaccine sparks immune response to fight cancer

ESMO 2025: mRNA-based COVID vaccines generate improved responses to immunotherapy

Drug combo cuts risk of death in advanced prostate cancer by 40%

ADC improves outcomes for patients with advanced triple-negative breast cancer who are ineligible for immune checkpoint inhibitors

Novel treatment combination improves progression-free survival in metastatic, estrogen-receptor-positive HER-2-negative breast cancer

ESMO 2025: Trial results show belzutifan shrinks rare neuroendocrine tumors and improves symptoms in patients

ESMO 2025: Dual targeted therapy shows promise in previously treated advanced kidney cancer patients

New generation of Antibody-Drug Conjugates (ADCs) shows unprecedented promise in early-stage disease

Sylvester Cancer Tip Sheet for October 2025

Three science and technology leaders elected to Hertz Foundation Board of Directors

Jump Trading CSO Kevin Bowers elected to Hertz Foundation Board of Directors

Former Inscripta CEO Sri Kosaraju elected to Hertz Foundation Board of Directors

Citadel’s Jordan Chetty elected to Hertz Foundation Board of Directors

McGill research flags Montreal snow dump, inactive landfills as major methane polluters

A lightweight and rapid bidirectional search algorithm

Eighty-five years of big tree history available in one place for the first time

MIT invents human brain model with six major cell types to enable personalized disease research, drug discovery

Health and economic air quality co-benefits of stringent climate policies

How immune cells deliver their deadly cargo

How the brain becomes a better listener: How focus enhances sound processing

Processed fats found in margarines unlikely to affect heart health

Scientists discover how leukemia cells evade treatment

Sandra Shi MD, MPH, named 2025 STAT Wunderkind

Treating liver disease with microscopic nanoparticles

Chemicals might be hitching a ride on nanoplastics to enter your skin

Pregnant patients with preexisting high cholesterol may have elevated CV risk

UC stroke experts discuss current and future use of AI tools in research and treatment

The Southern Ocean’s low-salinity water locked away CO2 for decades, but...

OHSU researchers develop functional eggs from human skin cells

[Press-News.org] Rodent robbers good for tropical trees