As an aid to the management of the Pyrenean population of the brown be
ar Ursus arctos, a sexing method based on the amplification of a Y chr
omosome specific sequence has been developed, and tested using hairs f
ound 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 s
mall amount of DNA, probably a single SRY gene molecule. The sex can r
eliably be identified using about 50pg of DNA extract as template. It
is possible that this approach could, with adjustments, be used to ide
ntify the sex of other species of eutherian mammals.