Blood Parasites of Birds of the High Rockies

Abstract

As far as I am aware, there are no published reports of the blood parasites of birds of the High Rockies. Since environmental conditions are quite different in such regions, with very short summers, uniformly cold nights (often with heavy frost), and low daytime humidity combined with moderate warmth and much sunshine, with consequent differences in the species of blood-sucking arthropods (possible parasite vectors) encountered, it seemed worth while to examine all birds available, even though many of them migrate during the winter either to lower altitudes or more southern ranges. There is also a somewhat different avian fauna at high altitudes. This study was done at the Rocky Mountain Biological Laboratory at Gothic (near Crested Butte), Colorado, at an altitude of 9,500 feet. Some of the birds were brought in from neighboring areas, up to 11,000 feet. The cliff swallows for the most part were taken from under the eaves of a small school building at Parkvale, a tiny hamlet a few miles west of Canon City, near the foot of Monarch Pass; some however were obtained under a cliff near Cement Creek, near Taylor Reservoir, some 25 miles from Gothic. Birds were either trapped or shot, or-in the case of juveniles-removed from the nests. Blood smears, supplemented in some cases by organ smears, were stained with J.S.B. All blood smears were examined under oil for a minimum of 5 minutes. The organ smears, and in some cases the blood smears also, were often studied much longer. Table 1 gives a summary of the species of birds included in the survey, and of the parasites found. The numbers are not large, but some of the results are of considerable interest and it seems worth while to report them, as the study cannot be continued in the near future.