In intersexual sleection, there are many, nonmutually exclusive indirect benefits to the female and her offspring. Females wnat to receive "good genes" for their offspring, and they ensure this by evaluating a potential male in a number of ways. Females will look for high amounts of symmetry because it has evolved to represent developmental stability. They will look at display vigor and quality, like in spider displays and canary trills. Females will counter in longetivity, meaning that they will generally go for an older male sice he has alreay proven that he can live long. In Bowerbirds, the amount of decorations on a male indicates his age, and therefore his wisdom. Freedom from disease is anotehr factor, and this could be indicated by plumage. Potential handicaps could also be something the female considers, in the thought process that if his male can survive with a handicap, he must be really otherwise fit. Lastly, lots of females try to mate with the correct amount of inbreedng and outbreeding in mind, based on the hypothesis that local mates are better. Swans do this by looking at facial markings, and mating with those that are similar but not identical.