you conduct a mark-recapture survey of eastern fence lizards (sceloporus undulates) in eastern arizona during the spring. you mark 250 lizards and are able to recapture 75, of which 24 are marked. you come back six months later and repeat the experiment. this time you mark 150 lizards initially, recapture 90, of which 12 are marked. what is the population growth rate (in months) for this population? assume exponential growth.