A Cottontail Rabbit Lens-Growth Curve from Southern Wisconsin

Abstract

A lens-growth curve, with confidence limits, was established from 188 known-age, pen-reared cottontail rabbits (Sylvilagus floridanus) between 2_ and 297 days old. Excessive variation in lens weights for any given age-class made it unlikely that year classes, other than young-of-the-year from adults, could be separated. Pen-reared cottontails from southern Wisconsin had heavier lenses and heavier body weights than those from central Illinois, at least up to 150 days old. After death, lens-weight loss due to decomposition increased with temperature. Greatest weight loss occurred during alternate freezing and thawing. At least 12 days were needed to dry lenses in a gravity convection oven.