There are two parts of this page. In the first part I described the results of this study back in 2008. In the second part I have revisited the study and described it again because I wasn’t happy with the first effort. I’m still not entirely happy but there it is.
Cat’s urine smell makes male mice more macho
The cat’s odor benefits a mouse when the mouse is a male mouse and the odor is that of cat’s urine and the animal that likes the effects of it is a female mouse. In other words, the odor of a predator (the cat) benefits the male mouse in this instance. If you would like you can read a summary of the findings by clicking this:
http://www.springerlink.com/content/q6r8525022717046/?p=eb8685e5979543258d3ee42c1c4b3ec0&pi=1. Link no longer works 13 years later 😢.
What is unusual is that “predator odor” (the cat’s urine) is usually frightening to prey. In this instance the mouse that had inhaled the cat’s urine produced urine himself that proved attractive to the opposite sex. It would seem that exposure by the prey (the male mouse) to the odor of a predator led to the prey becoming more macho and the females like macho mice!
If I am correct in the reading of this badly written summary (sorry) then it would seem that prey exposed to a predator increased the “macho” characteristics of the male mouse, which is attractive to the opposite sex (the female mouse), which in turn is a beneficial effect.
The exposure to cat’s urine also enhanced the aggression and the sex pheromones of the mice. The research was carried out to understand depression. I cannot see a connection! But there is a kind of connection in a roundabout way to the cat cartoons when a cat chases or becomes friendly with a mouse. Maybe the cat’s presence is making the prey (the mouse) more attractive to the cat.
Update December 30, 2021:
I think it might be useful to go over this. I’m not entirely happy with the way I described it many years ago!
My interpretation is as follows:
It would appear that female mice find more aggressive, macho male mice more attractive because they are better able to defend themselves against predators and I presume, therefore, better able to produce a family and strong offspring. It’s all about survival. Not different to human behaviour I would argue. In other words: the researchers concluded that the “presence of a low or moderate predation may be positive to prey”. What they appear to be saying that when a mouse senses that he is being preyed upon, they become more attractive to female mice. This is because they like aggressive males which is communicated in the smell of their urine. Male mice exposed to cat urine can appear to be strong males to females who can survive a predator.
It seems that a cat’s urine smell appears to act as an aphrodisiac for female mice. The smell makes male mice more macho, which helps to attract females the researchers said. Normally the smell of cat urine causes mice to flee. Certainly, a fleeing or stressed mouse is not going to be attractive to the opposite sex.
In the research they exposed mice to cat urine for eight weeks. After being exposed to cat urine for this length of time the male mice became more aggressive. There were more than twice as likely to fight with other mice. This heightened aggression was attractive to females hence the macho mouse description.
They found that female mice in heat spent more time sniffing urine from male mice who had been exposed to cat urine than ones that had been exposed to rabbit urine.
They planned to use the research findings to improve the life of animals in captivity. They could enrich the environment by simply adding the smell of a predator to stimulate them.
The study was published in the May 2008 issue of the Journal of Ethology.