Male and female chicks look different directly after hatching, which makes chick sexing extremely easy. The two chief methods of sexing chicks are feather sexing and vent sexing. One method of sexing cockatiels involves checking their pelvic bones. Most cross-breed strains are sex linked, allowing for easy chick sexing. DNA sexing is safer for the bird than surgical sexing. Sexing the birds is not as simple as telling a rooster from a hen chicken. Sexing this species is very difficult before sexual maturity is reached. As mentioned above, some mutations don't allow sexing by their feather patterns. Sound information can assist in the locating, watching, identification and sexing of birds. The specialized trade of chicken sexing has a particular importance in the poultry industry. Visual sexing is often possible with this variant of bird. Visual sexing is often possible with this variant of the bird. Bioarchaeological sexing of skeletons is not error-proof. As a second example, colour sexing broilers was proposed by Shaver in 1973.