SELECTIVITY OF MICROTRASH MATERIAL TYPE BY CALIFORNIA CONDORS.
Marie G. Solis; California Polytechnic State University, San Luis Obispo; 1 Grand Avenue, San Luis Obispo, CA, 93407; (805) 286-1829; mgsolis@calpoly.edu; Francis X. Villablanca
California condors consume non-food items, including anthropogenic waste, and provision it to their young. Consuming "microtrash" can cause mortality, especially in nestlings. There are several possible reasons explaining why condors might consume microtrash. One is that these birds require a source of bone (and calcium) because they feed primarily on muscle and viscera, and confuse microtrash for bone. Another is to provide material with enough binding potential to form into pellets, removing indigestible items. A third possibility is that this is an adaptive behavior of food stressed individuals. The first two explanations would be more likely if California condors had a preference for the materials they consume. The third explanation would be supported if condors simply took available materials. Therefore, to explore these explanations, we test the hypothesis that when California condors take microtrash, they show no material selectivity. We did this by sampling microtrash from six roadside pullouts in the Los Padres National Forest. Those samples will be compared to condor necropsy microtrash data, categorized by material type - glass, plastic, metal, other. Our prediction is that if condors are not selective, then proportions of microtrash types collected from pullouts should match the proportions of microtrash documented in necropsies.
Poster Session   Student Paper