75% of lig^P1 males dismount abnormally upon termination of copulation, compared to only a small percentage of controls.

Homozygous males do not show any generalised behavioural abnormality (such as inactivity, sluggishness or uncoordinated walking). Homozygous males initiate copulation with wild-type females just as often as wild-type males do, but are frequently unable to release the female's genitalia while mounted on the female's back. The mutant males tend to dismount the females without withdrawing their genitalia, and as a result, the male and female often tug at each other, pulling in opposite directions. In many cases, the mutant male and wild-type female remain stuck for several seconds to tens of minutes after copulation, until finally managing to separate from each other. 75% of mutant males mated to wild-type females show this "stuck" phenotype. Mutant females do not show any abnormalities in courtship behaviour, although they show only approximately 25% of the fertility of wild-type females. lig^P1/lig^PP1 male escapers show low locomotor activity compared to wild type in the absence of females, but court wild-type females as vigorously as wild-type males do. The mutant males are as active as wild-type males in performing the early steps of mating behaviour (chasing, tapping, singing and licking). After these steps, 73% of the lig^P1/lig^PP1 males attempt copulation with wild-type females, but only 24% of these succeed in copulation. lig^P1/Df(2R)lig^X4, lig^P1/Df(2R)lig^X13 and lig^P1/Df(2R)lig^X18 males show reduced mating success compared to wild type. lig^P1/Df(2R)lig^X4 male escapers show low locomotor activity compared to wild type in the absence of females, but court wild-type females as vigorously as wild-type males do. The external genitalia of homozygous or hemizygous males is indistinguishable from wild type and there are no obvious defects in the internal genitalia.