Wooing females was never that easy!
Does it pay to be a lover or a fighter, or both, to woo your lady?
This dilemma is often faced by male animals as mating season approaches.
Where animals fall on the lover or fighter scale depends on how much they are able to ensure continued mating rights with females, says a study.
In species where fighting for the right to mate means greater control of females - such as in the elephant seal - males invest more in weapons and less in love, said researchers from University of Manchester in England, Syracuse University in New York and University of Western Australia.
Some males found fighting the most successful method. Others found fighting was only the first step in sexual relations and also had to rely on large testes ensure their fertility.
The study, published in the journal Nature Communications, looked at over 300 species and found that males' ability to monopolise a female for continued mating drove the way they evolved.
The study looked at sexual behaviours in male mammals, birds, fish, insects and flatworms and found that males only traded-off investment in weapons and testes when they were sure that females would not fool around with another male when their back was turned.
"These findings help explain why some animals appear to invest maximally in expensive sexual traits but others are more frugal," said John Fitzpatrick, a lecturer in animal evolution at University of Manchester.
"The answer lies in how successfully males are able to keep females from mating with rivals," he added.
"Some of these species invest in both and that is a bit of a mystery. We would now look at whether maximising investment in sexual traits means you pay the price in some other aspect of life," the researchers added.
Other examples of males investing in weaponry are antlers in red deer, horns in dung beetles, spurs in pheasants and canine teeth in primates, the study said.
(Posted on 24-01-2014)