No duh. It's called display behavor. I can't believe they needed a study to come to this conclusion. Obviously conducted by undersexed PhDs that don't date much.
WASHINGTON (Reuters) - Women dress to impress when they are at their most fertile, U.S. researchers said on Tuesday in a study they say shows that signs of human ovulation may not be as mysterious as some scientists believe.
A study of young college women showed they frequently wore more fashionable or flashier clothing and jewelery when they were ovulating, as assessed by a panel of men and women looking at their photographs.
"They tend to put on skirts instead of pants, show more skin and generally dress more fashionably," said Martie Haselton, a communication studies and psychology expert at the University of California Los Angeles who led the study.
Display behavior in many mammals physically manifests in the form of Lordosis, commonly called "presenting". From Wikipedia:
Lordosis behavior, or Mammalian lordosis, is a sexual response during estrus in certain female mammals, such as mice and cats, that consists of a ventral arching of the spine. During lordosis, the spine curves so that the apex points in the ventral direction. That is, the convexity of the curve is on the side of the "belly" and the concavity of the curve is on the side of the back.
Lordosis aids in copulation, as it elevates the female genitals, so the male can more easily mate with the female. In female mice during estrus, the hormone, estradiol (a hormone of the class of hormones known as estrogens), affects neurons in the ventromedial hypothalamus, the periaqueductal gray and other areas of the brain. Sexual stimuli trigger activity in a number of brain areas, including the ventromedial hypothalamus, which sends impulses down axons synapsing with neurons in the periaqueductal gray. These convey an impulse to neurons in the medullary reticular formation which project down the reticulospinal tract and synapse with afferent neurons in the spinal cord (L1-L6) which contract muscles along the spine to exhibit the lordosis posture. Since these afferent neurons are also part of a reflex arc, lordosis can also be triggered reflexively.
See my post on the Bower Bird: The Bowerbird for Bic Disposable Razors