An analysis of the physical and ecological parameters sustaining populations of feather mites (Acarina: Analgoidea)

Abstract

It is the intent of this study to explore the inche and population structure of feather mites from four species of the family Icteridae: red-winged blackbird (Agelaius phoeniceus), common grackle (Quiscalus quiscula), brown-headed cowbird (Molothrus ater), Brewer's blackbird (Euphagus cyanocephalus), one species of the family Sturnidae (Sturnus vulgaris) and a sing species from the family Picidae (Cyanacitta cristata). From each of the 44 birds examined the remiges and ventral primary coverts were removed and population counts were made of mites directly from individual feathers. Differences in feather morphology were described by selecting three primary remiges (Nos. 3, 5, 7) and three secondary remiges (nos. 3, 5, 7) and measuring the barb widths from selected feather zones. Data were subjected to a factorial analysis of variance among feather types. Further analysis included the selection of an additional twenty-four characters from these feathers which were subjected to multivariate procedures. The procedures included character standardization, computation of similarity coefficients, cluster analysis, and ordination by principal component analysis and multidimensional scaling. From this data differences between birds and among feathers were noted. When the mite population is superimposed on the feather data evidence of host-partitioning was observed.