Ostrich reach an adult height of over 7 feet by 16 to 18 months of age. They continue to increase in weight after this time with adult males reaching over 300 pounds. Ostrich may become sexually mature at 2 years of age although males often mature later than females. It is not uncommon for hens to begin laying at 2 to 3 years of age while males may take as long as 4 to 5 years to be functionally mature. In captivity, females may lay as many as 100 egg in a season, although 20 to 40 are more common. Eggs are whitish in color, weigh about 3 pounds (1000 to 1500 grams) and are generally laid every other day. Eggs are typically laid in late afternoon. Although mating may occur numerous time during the day, it is believed that a single mating may be effective for up to a week.