Mate choice based on static versus dynamic secondary sexual traits in the dark-eyed junco

Adaptation, Exaptation, and Constraint: A Hormonal Perspective

“…Since older males also have naturally higher levels of T ), whiteness of tail and level of T normally covary with age. Hill et al (1999) eliminated this correlation and put T level in opposition to tail whiteness by elevating T in males with normal tails and enlarging the white area in tails of males with normal T. Some females preferred males with whiter tails, and some preferred males with higher T (i.e., males that sang more frequently and displayed more actively). Thus, plumage and male behavior are both attractive, each in its own right, and the two can interact to affect female choice.…”

The effect of past condition on a multicomponent sexual signal

“…Short-term signals would respond rapidly to momentary variations in condition, while long-term signals would lastingly reflect past condition, for instance during the period of juvenile growth and development. Befitting 'good genes' models, longterm signals may be especially important in female mate choice, because such signals may more reliably reflect the genetic quality of males than would signals subject to short-term environmental variation (Hill et al 1999;Kokko et al 1999). Several empirical studies confirmed that variation in trait expression might reflect male con-dition, as determined by current nutrition (Kodric -Brown 1989;Wagner & Hoback 1999) or degree of parasitism (Milinski & Bakker 1990;Møller et al 1999).…”

Mate choice in response to dynamic presentation of male advertisement signals in túngara frogs

“…courtship display vigour). Static traits are relatively invariant within an individual, while dynamic traits often vary considerably (Gerhardt et al 1996;Rosenthal et al 1996;Hill et al 1999). In addition to temporal variation in signals, receivers face spatial variation.…”