Sexing free-ranging brown bears Ursus arctos using hairs found in the field.

As an aid to the management of the Pyrenean population of the brown bear Ursus arctos, a sexing method based on the amplification of a Y chromosome specific sequence has been developed, and tested using hairs found in the field as a source of DNA. This method involves a two-step polymerase chain reaction (PCR) which allows the detection of a very small amount of DNA, probably a single SRY gene molecule. The sex can reliably be identified using about 50pg of DNA extract as template. It is possible that this approach could, with adjustments, be used to identify the sex of other species of eutherian mammals.