Nav: Home

Intense competition for reproduction results in violent mass evictions

March 01, 2016

Intense levels of reproductive competition trigger violent evictions of male and female banded mongooses from their family groups, University of Exeter researchers have found.

Dominant animals in this species are unable to stop subordinates breeding, leaving them with no resort except to throw them, kicking and screaming, out of the group.

Scientists observed a population of wild banded mongooses in Queen Elizabeth National Park in south west Uganda in a 16 year study. They found that evictions were extremely aggressive events resulting in the forcible expulsion of a group of females, sometimes with a group of males alongside them.

These mass eviction events were most likely to occur when the level of competition over who reproduces was at its greatest. Female banded mongooses were evicted when there were lots of breeding females in the group, and males were more likely to be evicted alongside females when there were lots of males competing to breed.

Banded mongooses live in cooperatively breeding family groups, meaning that all group members help to raise pups even if they don't breed themselves. All adult females breed together, giving birth to a communal litter on exactly the same day. Usually individuals live together peacefully but occasionally the group erupts into violence, which results in some individuals being aggressively attacked and driven away from the group.

The study, published in the journal Proceedings of the Royal Society B, shows that reproductive competition destabilises cooperative groups and that eviction can be a major source of gene flow in social animals.

Faye Thompson, a PhD researcher at the University of Exeter's Centre for Ecology and Conservation and the lead author of the study, said: "Banded mongooses, like many social animals, often show extreme levels of cooperation but occasionally these harmonious relations break down. Dominant females, and sometimes males too, aggressively evict members of their own family to reduce their level of reproductive competition.

"Banded mongooses rarely disperse of their own accord, and so eviction is one of the only ways that individuals form new groups. These eviction events result in the mass movement of genes through the population."

Professor Michael Cant from the University of Exeter's Penryn Campus, Cornwall, who leads the Banded Mongoose Research Project, said: "We've been studying these animals for 20 years, but it's only now that we are beginning to understand the long-term dynamics of the system. This work shows that within-group conflicts can have effects not only on the individuals involved, but also on the genetic structure of the wider population."
-end-
Reproductive competition triggers mass eviction in cooperative banded mongooses by Faye J. Thompson, Harry H. Marshall, Jennifer L. Sanderson, Emma I. K. Vitikainen, Hazel J. Nichols, Jason S. Gilchrist, Andrew J. Young, Sarah J. Hodge and Michael A. Cant is published in The Royal Society's Proceedings of the Royal Society B, and funded by the Natural Environment Research Council (NERC).

University of Exeter

Related Competition Articles:

Cell competition in the thymus is crucial in a healthy organism
The study published in Cell Reports demonstrates that the development of T lymphocytes lays on the coordination of signals followed by cells in order to ensure the maintenance of a healthy organism.
How sexual competition and choice could protect species from extinction
New research shows that removing sexual competition and choice through enforced monogamy creates populations that are less resilient to environmental stress, such as climate change.
Aging and nutrients competition determine changes in microbiota
Two studies with surprising discoveries: in the elderly, the bacterium E. coli evolves in a way that can become potentially pathogenic and increase the risk of disease and, according to data obtained in another study, the metabolism of the same bacterium present in the microbiota evolves differently if it is alone or accompanied by other bacteria.
Is human cooperativity an outcome of competition between cultural groups?
A study by ASU researchers looks at how culture may have fueled our capacity to cooperate with strangers.
Location and competition
Those of us who drive regularly are keenly aware of gas prices and their daily fluctuations.
Political competition is hurting our charitable giving
As the midterm election heats up and the fallout of the Supreme Court nomination rings across the political divide, a new study presents a unique angle of American politics: how party affiliation affects charitable donations.
For wineries, competition boosts profits from sustainability
An international study of small- to medium-sized wineries and vineyards finds that the more sustainability practices a winery has in place, the better its financial performance -- and the effect is enhanced when a winery perceives significant pressure from competitors.
Outside competition breeds more trust among coworkers: Study
Working in a competitive industry fosters a greater level of trust amongst workers, finds a new study from the University of British Columbia, Princeton University and Aix-Marseille University, published today in Science: Advances.
Step aside Superman, steel is no competition for this new material
When it comes to materials, there is no question as to who wins the strongman competition.
Competition between males improves resilience against climate change
Animal species with males who compete intensively for mates might be more resilient to the effects of climate change, according to research by Queen Mary University of London.
More Competition News and Competition Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: The Power Of Spaces
How do spaces shape the human experience? In what ways do our rooms, homes, and buildings give us meaning and purpose? This hour, TED speakers explore the power of the spaces we make and inhabit. Guests include architect Michael Murphy, musician David Byrne, artist Es Devlin, and architect Siamak Hariri.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

What If?
There's plenty of speculation about what Donald Trump might do in the wake of the election. Would he dispute the results if he loses? Would he simply refuse to leave office, or even try to use the military to maintain control? Last summer, Rosa Brooks got together a team of experts and political operatives from both sides of the aisle to ask a slightly different question. Rather than arguing about whether he'd do those things, they dug into what exactly would happen if he did. Part war game part choose your own adventure, Rosa's Transition Integrity Project doesn't give us any predictions, and it isn't a referendum on Trump. Instead, it's a deeply illuminating stress test on our laws, our institutions, and on the commitment to democracy written into the constitution. This episode was reported by Bethel Habte, with help from Tracie Hunte, and produced by Bethel Habte. Jeremy Bloom provided original music. Support Radiolab by becoming a member today at Radiolab.org/donate.     You can read The Transition Integrity Project's report here.