On 9 January 1977 James A. Gast of Arcata, California, picked up a dead Pied-billed Grebe (Podilymbus podiceps) at the mouth of Maple Creek, Humboldt County, California. Because there are relatively few documented cases of natural mortalities in birds, I present some information on this one.
The grebe, a robust male, weighed 564 g, and had a wing chord of 142 mm. A Prickly Sculpin (Cottus asper) protruded outward between the bird’s mandibles (Figure 1). The sculpin, a female, was 131 mm standard length (tip of snout to base of caudal fin), 153 mm total length, and weighed 42.4 g (preserved wet weight). It had large ovaries weighing 5.3 g, with maturing ova which caused the abdomen to bulge. The preopercular spine of each gill cover protruded slightly and appeared to be lodged in the gular skin of the grebe just posterior to the base of the mandibles. The entire gular region was examined for hemorrhaging, or obvious internal injuries. As none were discovered, I assumed the cause of death to be suffocation. Both bird and fish were in fresh condition.