A swamp rabbit life history study was conducted in Alabama during 1960-1967. Of 438 swamp rabbits taken by hunters on Wheeler National Waterfowl Refuge in northern Alabama during February, 205 (46 percent) were males. In a sample of 64 others collected statewide throughout the year, 29 (45.3 percent) were males. Late winter weights are presented for 322 swamp rabbits examined in north Alabama. Based on implantation sites or corpora lutea counts, the mean size of 95 first swamp rabbit litters of the season was 2.863. The mean size of 17 second litters of the year was 3.176. No significant differences were found between the size of litters from different latitudes or within different litter sequences. The onset of the swamp rabbit breeding season is well defined in northern Alabama, usually starting in mid-February, and slightly preceding the onset of the cottontail breeding season. The infrequent occurrence of young animals in late winter collections of swamp rabbits from northern Alabama indicates there is little or no fall or early winter breeding by swamp rabbits in that area. A lens weight histogram representative of February age distributions is presented. Based on ages determined by lens weights, a February sample of swamp rabbits contained 58 per cent juvenile which is less than is normally found in cottontail populations, perhaps suggesting greater life expectancy in swamp rabbits.
