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.
The roadrunner (genus Geococcyx), also known as a chaparral bird or chaparral cock, is a fast-running ground cuckoo that has a long tail and a crest. It is found in the southwestern United States and Mexico, usually in the desert. Some have been clocked at 20 miles per hour (32 km/h).