REPRODUCTIVE-BIOLOGY OF 4 SPECIES OF TROPICAL AUSTRALIAN LIZARDS AND COMMENTS ON THE FACTORS REGULATING LIZARD REPRODUCTIVE-CYCLES

We examined the reproductive cycles of four species of lizards through one year in the middle-latitude (19-degrees-S) seasonal Australian tr opics. The gonads of male Cryptoblepharus virgatus were active all yea r except during mid-summer (January-March), while female gonads were a ctive August through January. The reproductive condition of male Carli a pectoralis peaked during September through November, while female co ndition peaked in November through February. Male Heteronotia binoei r eached peak reproductive condition in July-September, but appeared to be capable of reproduction in April through November. Female gonadal a ctivity in H. binoei commenced in July, and continued through January. Lampropholis delicata males were in reproductive condition in all mon ths, while females were reproductive September-February. Female reprod uctive activity in all species except C. pectoralis commenced earlier in the year than in related species at higher latitudes. Because femal e reproductive activity in two of the species commenced in mid-winter, which is also the middle of the dry season, we do not believe that it is triggered by increasing temperature, photoperiod, or rainfall. Ins tead, reproductive activity may be controlled by total exposure to sol ar radiation, either across the spectrum or concentrated in the ultrav iolet.