Hunt, J. L.  1999.  Dietary overlap and potential competition among scaled quail, mourning doves, and northern bobwhites in southeastern New Mexico.  M.S. thesis, Auburn University, Alabama, 72 pp.

THESIS ABSTRACT

DIETARY  OVERLAP AND POTENTIAL COMPETITION AMONG SCALED QUAIL, MOURNING DOVES,

AND NORTHERN BOBWHITES IN SOUTHEASTERN NEW MEXICO

John L. Hunt

            In summer and autumn 1981-1988, 131 northern bobwhites (Colinus virginianus), 563 scaled quail (Callipepla squamata), and 880 mourning doves (Zenaida macroura) were collected in southeastern New Mexico to determine amounts and types of food items ingested and to evaluate variation in feeding habits by sex, age, time of day, and year.  Discriminant-function analysis was used to evaluate variation in feeding habits.  Diet of northern bobwhites, scaled quail, and mourning doves did not differ (P > 0.05) between sexes or age groups.  Northern bobwhites and scaled quail ate more (P < 0.025) animal material in morning than in afternoon.  Diet of all three species differed (P < 0.05) by month and year.  Diet of scaled quail and mourning doves in the absence and presence of northern bobwhites also was examined.  Diets of scaled quail and mourning doves in both August and October differed (P < 0.001), suggesting competition between northern bobwhites and the other two species.  Overlap in diet between scaled quail and mourning doves, and between scaled quail and northern bobwhites was measured using a simplified Morisita index of niche overlap.  Dietary overlap between scaled quail and mourning doves for August 1982-1988 was positively related to total annual precipitation.  During periods with reduced resources, scaled quail and mourning doves exhibited reduced dietary overlap, possibly to avoid competition; during periods of abundance of resources, overlap in diets increased.