Reproducción y variación de grupos de tama？o en una población de Liolaemus koslowskyi (Squamata: Liolaemini)

the reproductive pattern, the rate of growth and the survival are the main characteristics of the life history of organisms, the size or age in that an individual acquires his sexual maturity, the size of the maturity and the reproductive fenology affect the recruitment and therefore the stability of the populational size. different representative sites of the study area were selected, to carry out the extraction of the reproductive samples and for the observation of the populational dynamics, 12 samples were obtained from october 1998 to february 2000, during that period 413 females were studied, x = 55.48; (35-65) ds = 4.08 and 472 males, x = 57.75; (42-69) ds = 4.66. the proportion of sexes was similar, the smallest reproductive male measured 46 mm, the smallest female with vitelogenic follicles measured 47 mm. the presence of vitelogenic follicles was observed from october to january, eggs in oviduct from november to february, there were no evidence of more than one clutch per season, and fecundation takes place during the month of november, coinciding the maximum values of the testicular volumes. negative correlation between the reproductive activity and the cycle of fat bodies was observed in both sexes, the eggs are laid from december and the first hatchlings are observed in january. there was a negative correlation between the rate of individual growth and the size of the lizard. during the period of study 2199 lizards where observed and the proportion of each size group was calculated for every month, in january 15% of recently born individuals were observed in the site, the highest activity rate in the site corresponded to january, february and march of 1999, diminishing in autumn and no activity was registered in june and july. the second season presented less activity than the first one.