- The more times bustards performed their 'flirting' mating ritual, the more their fertility declined
Last updated at 10:09 AM on 4th August 2011
Indulging in overt sexual behaviour could lead to premature ageing in men through 'burnout', according to scientists studying fertility patterns in birds.
A 10-year research programme into the sex lives of bustards, birds with a very flamboyant mating display, showed a dramatic decline in the quality of sperm among the more 'showy' males.
The mating display of the male Houbara bustard, known as 'booming', sees striking ornamental feathers flare up before the bird runs around while making a low-pitched call.
'Booming': Scientists have found a link between sexual behaviour and ageing among Hubari bustards, which flare their feathers in a distinctive mating ritual
The study of more than 1,700 North African Houbara bustards showed that the more times male birds performed the ritual, the more the quality of their sperm declined for what the scientists believe is an age-related reason.
'Over the age of six years they began to produce much smaller ejaculates with immobile and frequently abnormal sperm,' lead researcher Dr Brian Preston Preston told the BBC.
'But the key finding was that males that had invested most effort displaying to females in their earlier years experienced the onset of this age-related decline in fertility at a younger age.
'They effectively seem to "burn themselves out" sooner.'
Off duty: The same bustard before beginning its 'booming' mating ritual, seen here with its feathers flat
The birds, a threatened species, were bred in captivity in Abu Dhabi, in the United Arab Emirates, as part of a programme designed to boost their numbers in the wild.
Bustards are ripe for the study because they live for so long, and the study examined birds aged from one to 24.
The males can 'boom' for as much as 18 hours a day, six months of the year.
Dr Preston, who is based at the University of Burgundy in France, led his team in measuring the length of time each male spent 'booming', and then compared that with changes in fertility, which is usually associated with ageing.
The more time the birds spent 'booming', the more dramatic was the decline in their fertility.
Dr Preston said that genes which cause birds to deteriorate with age would usually be 'weeded out' by natural selection and the fact that it does not happen is a significant anomaly.
Evolutionary biologists advance the theory that animals - unsure how long they might live in a world where they could be picked off by predators - can 'overspend' their energy.
In a biological trade-off, they exhaust their energies in early life, leaving themselves unable to properly maintain their bodies as they get older.
04 Aug, 2011--
Source: http://www.dailymail.co.uk/sciencetech/article-2022289/Do-flirts-age-faster-Link-overt-sexual-displays-aging-scientists-bird-breeding-programme.html?ITO=1490
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