- The main purpose of this study was to ascertain the importance of the domestic cat in the Willamette Valley as a game bird predator; additional reasons were to learn more of its life history and food habits, and to analyze the popular belief that the cat, feral or non-feral, is the greatest predator of birdlife known. Location of Study: The region in which investigation was made was the Willamette Valley, Oregon, which is situated 40 miles inland from the Pacific Ocean, in the northwest quarter of the State of Oregon. Investigational Procedure: The following seven methods were used in obtaining necessary data: 1. A detailed review of similar past studies of the cat as a predator. 2. A census of 416 farms. 3. Information from 425 4-H Club questionnaires. 4. Field observations. 5. Trapping and hunting of cats for specimens for stomach analysis. 6. Identification of food items in cat scats. 7. Stomach alalysis by Charles C. Sperry, Associate Biologist, United States Bureau of Biological Survey. Summary of Findings: 1. There are approximately 94,000 farm cats in the Willamette Valley, or an average of 2.85 cats per farm. 2. The feral cat population in the Willamette Valley is estimated at approximately 11,000. 3. Total population of feral and non-feral cats for the entire Valley, exclusive of cities and towns, is conservatively estimated as being over 100,000. 4. The average female farm cat has two litters annually, with a mean average of 4.85 kittens per liter. 5. Most farmers value their cats as mousers at $10.00 to $50.00 annually. 6. Examination of 63 cats scats showed that 55.6 percent of the material by occurrence was principally of rodent origin. Fifteen field mice were identified out of a total of 35 rodents. 7. The food items found from stomach analysis of 86 cats were principally confined to the Order Rodentia, in which five species made up by volume 45.09 percent of the total food examined. Field mice, Microtus spp., were found in 26 stomachs (22.85 percent), and the Oregon brush rabbit, Sylvilagus bachmani ubericolor (Miller), was second in being found in 11 stomachs (12.12 percent). Only two California quail, Lophortyx californica vallicola (Shaw), and one western mourning dove, Zenaidura macroura marginella (Woodhouse), was found, making 3.37 percent the total volume for game birds. Conclusion: The most important general conclusion reached in this investigation is that the stomach analysis of the feral and rural cat do not bear out the contention that the domestic cat in Willamette Valley is confirmed game bird consumer.