Food Habits and Intensity of Coccidian Infection in Native Valley Quail in California

Abstract

Examination of fecal samples from large series of California quail (Lophortyx californica), taken in various areas in California during 1941, showed a high incidence of coccidian infection. Herman and Jankiewicz (1942) have demonstrated that the infection reduces to a minimum in the absence of material contaminated with ripe coccidian o6cysts. Herman, Jankiewicz and Saarni (1942) showed further that, under natural conditions, the intensity of infection in individual quail tends to fluctuate, probably decreasing as the parasites are eliminated and increasing with the repeated ingestion of o6cysts. A possible relationship between the intensity of coccidian infection and food habits was observed from data on fecal samples of quail from the San Joaquin Experimental Range, Madera County, California. The type of food consumed by these birds varies according to the season. They subsist primarily on seeds during the dry summer and early fall, but after the first rains the diet becomes predominantly green leafy material, as demonstrated by Glading, Biswell and Smith (1940) from the analysis of quail stomachs taken on the experimental range. Data for the present study are based on the examination of 342 fecal samples procured from April 1941, through February 1942. The procedure followed has been described by Herman, Jankiewicz and Saarni. Intensity was computed by the number of o6cysts present in a single drop of surface film of the concentrated zinc sulfate centrifuged material (1-10, 1 4-; 11-50, 2 +; 51-100, 3 +; 101-500, 4 +; 501-1000, 5 +; over 1000, 6+). Tabulations were made by individual samples, no consideration being given to individual birds. In computing the data presented in section C of the graph, negatives were considered as 0, each 1 + infection as 1, etc. The average (points plotted) was obtained by dividing the sum of the infections for each month by the number of samples examined. Section A of the graph presents the actual inches of rainfall during the period of the study. Section B pictures the probable food consumption (for the period March 1941, through February 1942) interpolated from 1937 data of relation of rainfall to per cent of composition of food consumed (after Glading, Biswell and Smith, 1940). Becker and Waters (1939) reported that alfalfa contains liberal amounts of the liypothetical materials for promoting coccidium growth as compared with grains,