Possible Limiting Factors of the Ringneck Pheasant Population in Southern Rhode Island

Abstract

The purpose of this project was to investigate the possible limiting factors of the ringneck pheasant population in southern Rhode Island. Two factors, food and weather, were considered in detail. The research area chosen was a typical non-urban area of southern Rhode Island, the Great Swamp Wildlife Reservation, in the township of South Kings town. This reservation has been under t he supervision of t he State Division of Fish and Game for the past six years. Census and life history studies were abandoned. after a year of weekly observations because of failure to collect significant amounts of data. An analysis by occurrence and volume was made of foods found in 64 crops collected from wild and stocked pheasants throughout the State during November, 1955. Wild birds ate a greater volume and a larger number of species of wild foods than stocked birds, although cultivated grains made up almost two-thirds of the food volume. In a fall and winter plant survey , only eight food species, making up less than one percent of t he total volume of foods eaten, occurred as dominants in uncultivated areas. It was concluded that together with the low grain acreages in Rhode Island, the abundance of native plant foods was too low to sustain a large pheasant population through the winter. Preliminary examinations were made of the sands and gravels in six 100- gram soil samples taken in or near the Reservation; the calcium-bearing minerals found were chlorite and a black carboniferous schist, both in amounts less than one-tenth of one percent. The results indicated that it is possible that a lack of calcium in the soil may be one of the limiting factors of the Rhode Island pheasant populations. A Bendixaerograph, recording temperature, relative humidity, and barometric pressure was set out in the Reservation in July, 1954 , three inches above the ground, enabling a comparison between three-inch and standard five-foot temperatures . Temperatures near the ground were colder at night, warmer during the day, conditions that tend to affect chicks adversely after sundown but favorably during the day . When the weather for the spring and summer in Rhode Island was compared wit h that in regions of the United States with high pheasant populations, the important differences noted were that Rhode Island has less sunshine, more cloudy days, fewer clear days, and longer lasting storms. Because young pheasant chicks are exceedingly