Birds prove wisdom of 'opposites attract'
Cockatiels demonstrate recipe for a happy union.
Attention henpecked husbands: animal experts have shown that, for cockatiels at least, a one-sided relationship is the best way to ensure harmonious family life.
The cockatiel mating game is largely a case of 'opposites attract', says Rebecca Fox of the University of California, Davis, who led the research. She found that cockatiels (Nymphicus hollandicus) actively seek out potential mates with a personality different to their own, and that these unions tend to progress most smoothly.
"Cockatiels are similar to us in the way they have relationships," says Fox. "They have long, cooperative partnerships, raise young together, and compatibility is important to them. It's something people can relate to."
The most important consideration for the birds is how agreeable or aggressive their partner is, Fox found when studying their mating tactics. Most aggressive cockatiels tend to court only those that are more docile, and vice versa.
This might sound like a recipe for disaster. But it avoids conflicts that might damage the welfare of the birds' young, she explains. "The more agreeable partner is likely to back off and let the less agreeable one cool down in the case of conflict," she says.
Fox made the discovery by first analysing the 'personalities' of 15 male and 15 female cockatiels, classifying each according to their agreeableness, boldness and tendency to socialize.
She then set up a form of cockatiel 'speed dating' by placing several males and females in an enclosure and letting them pair off. Some 90% of partnerships featured one meek and one overbearing partner, she told the Animal Behavior Society meeting in Snowbird, Utah on Monday 14 August. Other personality traits had little effect, although there was also a small tendency for bold birds to pair up with shy ones.
The result is a surprise, says Fox she had initially expected like to be attracted to like (birds of a feather, after all...). But with hindsight it seems logical that domineering relationships would work well. Similar results might be seen in other species that form long-term partnerships, such as great tits, although few have been studied so far, she adds.
Not quite all relationships were lop-sided, however. A minority of partnerships featured two mild-mannered birds, although none featured the nightmare scenario of two strong-willed partners. Fox points out that the pairing of two agreeable birds might also be a recipe for avoiding conflict.
But this courtship strategy was only attempted by a few meek males, most of whom did not succeed in snaring a female at all. Fox suggests that mild manners are not a strong attractor for females because meek males might struggle to defend their territory. The female birds seemed predominantly to be attracted to strong-willed partners.
Nevertheless, domineering females do seek out meek males, perhaps because they sense that the strong-willed males will not put up with their aggression. This suggests that making marriage work is paramount for cockatiels, and that the other ingredients of attraction only come in later. "First they have to select individuals they can actually get along with as mates," Fox explains.
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