Menarche. The average age of menarche, or first menstruation, in the United States is 12.88 years for Caucasian girls and 12.16 years for African American girls.A popular misconception is that menarche marks the beginning of puberty; in reality, menarche occurs later in puberty.enarche. The average age of menarche, or first menstruation, in the United States is 12.88 years for Caucasian girls and 12.16 years for African American girls.
Quick Answer. Roadrunners eat insects, lizards, scorpions, small birds, rodents and snakes, including rattlesnakes. During the winter months when its preferred food is scarce, the roadrunner may supplement its diet with fruits, seeds and other vegetable matter. Continue Reading.
Four species live in the park; the Devil's Hole pupfish is an endangered species. Roadrunner (bird) These ground-dwelling birds are found in the lower elevations of Death Valley. They eat lizards, insects, snakes, and small birds. picture & summary Great-tailed Grackle (bird) These sleek birds are often found in noisy flocks near developed areas.