The best laid plans: analyzing courtship defects in Drosophila. 
Courtship can be defined as behavioral interactions between males and females, the evolutionary objective of which is copulation and the ultimate perpetuation of the species.  This protocol allows determination of two aspects of courtship in Drosophila: to assess whether there is a deficiency in mating frequency and, if this is the case, to resolve the nature of the specific problem.  The first part of the approach provides a simple, objective, high-throughput strategy that is ideal for determining whether a specific strain has any courtship defect.  Any strain that mates at a frequency comparable to that of wild-type flies must be considered reasonably fit in an evolutionary sense.  If a specific strain has an abnormal mating frequency, we are then interested in determining whether there is a specific courtship defect, as described in the second half of the protocol.  This requires direct live observation or digital recording of courtship.