(Press-News.org) Male Cardiocondyla obscurior ants are diphenic (either winged or wingless). New research published in BioMed Central's open access journal BMC Ecology demonstrates that the dominant wingless (ergatoid) male is able to identify potential rivals before they emerge from their pupae. Constant patrolling of the nest ensures that this male is able to bite or chemically tag rivals as soon as they emerge from their pupae. Chemically tagged ants are quickly destroyed by workers.
When ants emerge from their pupae (eclosion) they are vulnerable to attack because their exoskeleton has not yet hardened to protect them and their mandibles are also too weak to bite an attacker. Researchers from University of Regensburg and IST Austria investigated the behaviour of male ergatoid C. obscurior ants in response to newly pupated males and females as well as their interaction with developing pupae.
It would be advantageous for newly emerged males to hide from attackers. However, while winged males use chemical female mimicry to avoid being detected, young ergatoid males are easily detected and attacked by older males. If the fight occurs during the first day after eclosion the older male will always win but once the younger male's exoskeleton hardens his chances of surviving rises to 14%. Nearly 50% of fights between older and two-day old males results in the death of both combatants.
In addition to biting the males also smeared each other with secretions from their anuses which encouraged worker aggression. The older males were more likely to chemically tag two-day olds than younger rivals (presumably recognising that they needed help to win the fight) however since both males end up being tagged they both suffer worker attacks. The winners of these fights smear more and are attacked less by workers. So although this tactic overall may provide an 'edge' it is a risky strategy.
Dr Sylvia Cremer, from IST Austria, who led this project commented, "Older ergatoid male ants are able to distinguish pupae containing females by their chemical scent from those containing males. Pupae containing males are often bitten while those containing females (or winged males disguised as females) elicit a mating response. However the chances of mistakenly killing a female or worker possibly prevents older males from attempting to completely destroy all rival males before they emerge from their pupae."
C. obscurior ants produce sexual females and ergatoid males throughout the year. In terms of colony survival this ensures that if the old dominant male dies there is a new male ready to replace him. The cost of producing a constant supply of ergatoid males is low compared to the cost of producing unfertilised females, and any killed males are recycled as food for the larvae.
INFORMATION:
Notes to editors
1. The dynamics of male-male competition in Cardiocondyla obscurior ants
Sylvia Cremer, Masaki Suefuji, Alexandra Schrempf and Juergen Heinze
BMC Ecology (in press)
Please name the journal in any story you write. If you are writing for the web, please link to the article. All articles are available free of charge, according to BioMed Central's open access policy.
Article citation and URL available on request at press@biomedcentral.com on the day of publication.
2. BMC Ecology is an open access, peer-reviewed journal that considers articles on environmental, behavioral and population ecology as well as biodiversity of plants, animals and microbes.
3. BioMed Central is an STM (Science, Technology and Medicine) publisher which has pioneered the open access publishing model. All peer-reviewed research articles published by BioMed Central are made immediately and freely accessible online, and are licensed to allow redistribution and reuse. BioMed Central is part of Springer Science+Business Media, a leading global publisher in the STM sector.
The boys are bad: Older male ants single out younger rivals for death squad
2012-06-15
[Attachments] See images for this press release:
ELSE PRESS RELEASES FROM THIS DATE:
Gene may link diabetes and Alzheimer's, CCNY researchers find
2012-06-15
In recent years it became clear that people with diabetes face an ominous prospect – a far greater risk of developing Alzheimer's disease. Now researchers at The City College of New York (CCNY) have shed light on one reason why. Biology Professor Chris Li and her colleagues have discovered that a single gene forms a common link between the two diseases.
They found that the gene, known to be present in many Alzheimer's disease cases, affects the insulin pathway. Disruption of this pathway is a hallmark of diabetes. The finding could point to a therapeutic target for both ...
Amazon was not all manufactured landscape, Smithsonian scientist says
2012-06-15
Population estimates for the Amazon basin just before Europeans arrived range from 2 to 10 million people. The newly reported reconstruction of Amazonian prehistory by Smithsonian scientist Dolores R. Piperno and colleagues suggests that large areas of western Amazonia were sparsely inhabited. This clashes with the belief that most of Amazonia, including forests far removed from major rivers, was heavily occupied and modified. The team's research is published in the June 15 issue of Science.
"Drawing on questionable assumptions, some scholars argue that modern Amazonian ...
Why doctors still rely on century-old heart test
2012-06-15
VIDEO:
When it comes to diagnosing heart disease, experts like Dr. Martha Gulati of the Ohio State Wexner Medical Center are cautioning against relying too heavily on high-tech imaging, and are...
Click here for more information.
(COLUMBUS, Ohio) June 2012 – Most people might assume that technology first developed in 1928 would be obsolete by now. But from air conditioned buildings to sliced bread, many inventions of that era are still essential to our lives today. That ...
Child survival takes center stage as leaders convene to renew commitments
2012-06-15
With an unprecedented commitment that bridges the urgent need to address diarrheal disease with unique opportunities to overcome it once and for all, leaders in global health issued today's Declaration on Scaling-up Treatment of Diarrhea and Pneumonia. PATH joins the US Agency for International Development, the Clinton Health Access Initiative, the Micronutrient Initiative, and others in raising a collective voice, calling for investments to scale-up the use of proven tools, particularly oral rehydration solution, zinc, and amoxicillin.
"We call on all high-burden countries ...
Still capable of adapting: Research team studies genetic diversity of living fossils
2012-06-15
The morphology of coelacanths has not fundamentally changed since the Devonian age, that is, for about 400 million years. Nevertheless, these animals known as living fossils are able to genetically adapt to their environment. This is described by PD Dr. Kathrin Lampert from the RUB's Department of Animal Ecology, Evolution and Biodiversity along with colleagues from Würzburg, Bremen, Kiel and Dar es Salaam (Tanzania) in the journal Current Biology. "Coelacanths are rare and extremely endangered. Understanding the genetic diversity of these animals could help make preservation ...
European geneticists condemn use of testing to establish 'racial purity'
2012-06-15
The use of genetic testing to establish racial origins for political purposes is not only scientifically foolish, but also unethical and should be condemned, the European Society of Human Genetics (ESHG) said today (Thursday June 14). The society, which promotes research in basic and applied human and medical genetics and ensures high standards in clinical genetic practice, said that the use by a member of parliament from the Hungarian far-right Jobbik party of a genetic test to attempt to prove his 'ethnic purity' was ethically unacceptable.
The company Nagy Gén scanned ...
Training people to inhibit movements can reduce risk-taking
2012-06-15
New research from psychologists at the Universities of Exeter and Cardiff shows that people can train their brains to become less impulsive, resulting in less risk-taking during gambling. The research could pave the way for new treatments for people with addictions to gambling, drugs or alcohol as well as impulse-control disorders, such as ADHD.
Published today (14 June 2012), in the journal Psychological Science, the study assessed whether asking people to stop making simple movements while in a simulated gambling situation affected how risky or cautious they were ...
Training character strengths makes you happy
2012-06-15
Character strengths can be defined as traits that are rated as morally positive. That they are positively linked to life satisfaction has already been shown in many studies. That they have a causal effect on life satisfaction and that practicing them triggers an increase in the sense of wellbeing, however, has now been proved by Willibald Ruch, René T. Proyer and Claudia Buschor from the Department of Personality and Assessment at the University of Zurich for the first time.
Practice pays off
For their current study, the team of researchers randomly divided a sample ...
How many cells can our blood tolerate?
2012-06-15
When people say "Blood is thicker than water," they are literally right. Because nearly half of the 'life liquid' consists of solid components. The red blood cells form the greatest part of it – all in all around 40 percent of the blood. They contain the red pigment hemoglobin and are responsible for the transport of oxygen.
"It is amazing that the percentage of this component is not only similar in all human beings but also in many other vertebrates," Prof. Dr. Stefan Schuster of the Friedrich Schiller University Jena (Germany) says. Therefore it can be assumed that ...
Making the invisible visible
2012-06-15
While youth suicide is declining overall, the rate of youth suicide in rural America has remained steady. A key to helping rural families with children at risk of suicide is frank discussion of guns says Jonathan Singer, assistant professor of social work at Temple University and co-author of a new study that examined how clinicians, including social workers and counselors involve parents in prevention and treatment of youth suicide. The study, "Engaging parents of suicidal youth in a rural environment" was published in the May issue of Child & Family Social Work.
Singer ...