A total of 236 eggs were laid by the population of the wildcrested ibis (Nipponia nippon) in 72 nests in Yang County,Shaanxi Province,China,from 1981 to 1997,with an average of 3.3 eggs per nest.Among the eggs,169 nestlings were hatched,accounting for 71.6% of the total；and 129 young birds grew up and flew from their nests,accounting for 76.3％ of all the nestlings.Since 1981,133 birds have been brought up in the county.The birds have established 27 breeding sites in the county,with the number of breeding couples increasing from 2 pairs in 1981 to 10 pairs in 1997.The birds mature at 2 years old,either male or the famele is 2 years old,The maximum age difference between the 2 sides of a couple is 2 years.