Date of Award:

1973

Document Type:

Thesis

Degree Name:

Master of Science (MS)

Department:

Wildland Resources

Advisor/Chair:

Jessop B. Low

Abstract

Primary objectives of this study were: (1) to compare the food habits of healthy and botulism intoxicated American avocets and blacknecked stilts for qualitative and quantitative differences, (2) to determine .which invertebrates found in the tracts of intoxicated and healthy birds contained type C toxin, and (3) to explain apparent susceptibilities among different sexes, ages and species of birds.

Based on percent utilization and occurrence of food items in the esophagus , the diets of healthy and intoxicated birds were similar. However, intoxicated avocets consumed higher proportions of Gastropoda and intoxicated stilts more Hydrophilidae larvae than did healthy birds. Because of similarities in diets of healthy and intoxicated birds, birds probably became intoxicated from eating randomly toxic foods and not because of differences in diet or food preference.

Examinations of esophageal contents of avocets and stilts better described recently consumed food items than did examinations of gizzard contents. Soft-bodied invertebrates were rendered unidentifiable in the gizzard. The esophageal contents of juvenile avocets and stilts contained greater proportions of animal matter than did those of adults.

Only three of 86 food samples analyzed were definitely positive for type C botulism toxin. These were: one sample of Tendipedidae larvae and two of pooled gizzard contents which included fragments of Corixidae, Hydrophilidae adults, seeds and vegetative fibers.

Only three of 86 food samples analyzed were definitely positive for type C botulism toxin. These were: one sample of Tendipedidae larvae and two of pooled gizzard contents which included fragments of Corixidae, Hydrophilidae adults, seeds and vegetative fibers.

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