Ecology of feral house cats (Felis domestica) on Santa Catalina Island, California

Santa Catalina Island, twenty-two miles off the southern California coast, Has the site of a study on the ecology of feral house. cats (Felis domestica). Observation of behavior physical characteristics and capture sites were used to determine whether a cat was existing in a feral state. All cats observed or captured on the island were in good physical condition, appeared to prefer dense chaparral with rocky outcroppings and were more abundant near dumps and water supplies. Examination of the digestive tracts of twenty-three cats revealed certain food preferences; 95% of the digestive tracts contained insects, 81%had vegetation, and 64% had garbage, rodent remains were found in 41%, bird remains in 22%, and reptilian forms in 23%. Digestive tracts of 68% of the cats had internal parasites. A computer analysis of factors which would discriminate between the island sample and a sample collected from the West Valley Animal Shelter in Chatsworth, California was performed. The analysis showed that the length of the maxillary tooth row, the tympanic bulla length, the greatest width of the zygomatic arch and the mandibular length were the most powerful discriminating measurements. It is suggested that stronger controls be placed on cat owners to eliminate the constant drift of cats from populated areas in conjuction with the gradual elimination of feral cats already on the island.