CHARACTERISTICS AND ADAPTIVE SIGNIFICANCE OF LATRINES OF SWAMP RABBITS (SYLVILAGUS-AQUATICUS)

Three different types of forests (mature, mixed upland, and cut-over) in central Arkansas were surveyed in June and October 1991 and Februar y and May 1992 for latrines of swamp rabbits (Sylvilagus aquaticus). S wamp rabbits deposited >91% of their fecal pellets on logs. A greater density of pellets were found in February 1992 compared to other month s. Length, height, diameter, decay class, and percent cover of moss on logs used as latrines by swamp rabbits were recorded. Logistic regres sion was used to predict the Likelihood that a log would be used as a latrine. Increasing decay class, percentage cover of moss, and diamete r of logs were correlated with latrines of swamp rabbits. Height of lo gs did not distinguish between used and unused logs, but length and se ason were significant predictors of use of logs as latrines in forests of mature bottomland hardwood and cut-over bottomland. Spatial clumpi ng of latrines and peak use during breeding were consistent with the h ypothesis that latrines on logs serve as territorial markers. An alter native hypothesis that swamp rabbits elevated themselves on logs to in crease their field of view and coincidentally deposited pellets on log s was tested experimentally with three obstruction treatments; visual + physical, only physical, and a control. Treatments were placed on I- m sections of 54 logs that had been used as latrines in at least 2 of the 4 monthly surveys. Surveys conducted for 4 months after the instal lation of obstructions showed a significant interaction between use of a log as a latrine, treatment type, and month of survey.