Males decide how much effort they put into courtship and which females to court based on how many others they have recently encountered and how attractive they were, according to a new study into the mating tactics of tropical fish.

Males also seem to change their opinions about how good-looking a female must be before they attempt to woo her, depending on what kinds of social experiences they have recently had, says the study published in the journal Evolution.

"This study reveals the sophisticated process that determines mating decisions and shows a very strong effect of the social environment in the evolution of reproductive behaviour generally," says Dr Alex Jordan, of the UNSW Evolution and Ecology Research Centre, who co-authored the study with the centre's director, Professor Rob Brooks.

"When males have recently encountered only few females - what you might call in the dating game a 'dry spell' - they expend significantly more effort in courting new females when they do meet up," says Dr Jordan.

"In contrast, males that have been in a 'purple patch', encountering numerous females in their recent past, are far more relaxed in the presence of subsequent females, and court these new females about half as strongly as desperado males."

Read the story in the Faculty of Science newsroom.