The Northern Cardinal is a widely recognized sexually dimorphic bird species with brilliant red males. The color of males is attractive not only to birdwatchers, but also to the comparatively plain female cardinals. According to a study by Wolfenbarger (1998), more chromatic males perform better competing for mates. Redder males also control more advantageous breeding territory and gain access to the season's earliest breeding females. By outcompeting their less colorful rivals, males pass on genes for brighter color, perpetuating the characteristic cardinal red.