Effect of a Contraceptive Compound on Reproduction of Greater Long-tailed Hamsters (Tscherskia triton) in Experimental Enclosures

We tested the effects of a contraceptive compound of levonorgestrel and quinestrol (coded as EP-1) on reproduction of greater long-tailed hamsters in eight experimental enclosures.The test subjects were divided into four groups with two replicates for each group: control group (0% EP-1), 0.001% EP-1 group, 0.003% EP-1 group, and 0.003% EP-1 group with pre-baiting before test. In June of 2001, each enclosure was supplied with 5 male and 5 female adult greater long-tailed hamsters, and with baits. In September, twelve newborn hamsters were captured in both control enclosures.Thus, each female produced an average 2.4 newborn hamsters. Less than four newborn hamsters were captured in each of the six EP-1 treatment enclosures, thus,each female produced an average of 0.4-0.8 newborn hamsters. The results indicated that the reproduction of hamsters in enclosures with treatment of EP-1 baits was obviously inhibited. Thus we suggest that in natural conditions, EP-1 would be promising in controlling reproduction of hamsters if they are supplied with enough baits.