Related BBC sites

Page last updated at 09:24 GMT, Tuesday, 26 April 2011 10:24 UK
Fallow deer stags butt-in to assert dominance
By Ella Davies
Earth News reporter

Fallow deer fight in Phoenix Park (c) William Clarke, University College Dublin
Bucks that butt-in get the girls

Male fallow deer intervene in fights between rivals to assert their dominance, according to scientists.

Studying the bucks during the mating season, researchers say they found the first evidence of strategic behaviour in deer.

By interrupting fights, males are able to display their dominance whilst subduing multiple competitors.

These fights happen annually during the autumn mating season or "rut" when males compete for access to females.

There can really only be a despotic explanation for this behaviour in deer
Dr Domhnall Jennings
Newcastle University, UK

Researchers from Newcastle University, UK, University College Dublin, National University of Ireland, Galway and the Galway-Mayo Institute of Technology, Ireland made the new observations.

They studied a herd of over 500 fallow deer in Dublin's Phoenix Park to learn more about behaviour during the rut.

Their findings are published in the journal Animal Behaviour.

Fallow deer form sexually segregated herds for most of the year but "batchelor herds" of males move onto female ranges from the beginning of September.

During the rut, bucks are known to engage in fierce combat in order to prove their dominance and gain access to females.

RUT FACTS
Fallow bucks walk in parallel (c) William Clarke, University College Dublin
The rut is a noisy time when males "groan" to call out rivals
Competing males strut shoulder to shoulder to size each other up
Males fight using their powerful antlers that regrow every year
Competitions can be "to the death" via injury or sheer exhaustion

Previous studies have highlighted how age, body size and antler size are important qualities that determine which buck will be triumphant.

However, research by Dr Domhnall Jennings and his team identified an added layer of complexity to the male deers' behaviour.

Scientists observed individual bucks intervening in fights between two other rivals, but Dr Jennings explained, the deer were not acting as peacekeepers.

"Diplomatic explanations have been used for intervention behaviour in primates as a means of enhancing group stability and cohesion," he told the BBC.

"This is not the case here since the bachelor herd has dispersed and males are extremely intolerant of each other's presence during the rut."

Rather than trying to maintain harmony in the group, researchers found that the fallow bucks strategically interrupted fights to improve their own status.

"There can really only be a despotic explanation for this behaviour in deer; [intervening males] benefit directly from their behaviour whereas the originally competing males do not," said Dr Jennings.

SOURCES

After interrupting the fight, dominant males then went on to defeat one rival whilst ignoring the other, leaving the original contest unresolved.

"As a result of having their fight interrupted in this manner, the original competing pair of males retain their status quo... the time and energy they have spent on fighting is wasted while their ability to advance in the hierarchy and mate is also impaired," said Dr Jennings.

Researchers say this work represents the first evidence of strategic behaviour in deer.



Print Sponsor


SEE ALSO IN EARTH NEWS
MSPs back 'asbo bambi' cull order
23 Feb 11 |  South Scotland
Climate link to 'early' deer rut
14 Jan 11 |  Highlands & Islands
'Biggest stag' Emperor shot dead
28 Oct 10 |  Devon
Scotland's deer 'changing shape'
16 Dec 09 |  Earth News
Stags locked in 'mortal combat'
06 Oct 09 |  Earth News

OTHER RELATED BBC LINKS


MOST POPULAR STORIES

From Science/Environment in the past week

  • TUESDAY :
  • MONDAY :
  • SUNDAY :

BBC navigation

BBC © 2014 The BBC is not responsible for the content of external sites. Read more.

This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.

Americas Africa Europe Middle East South Asia Asia Pacific