Clyde was a lover of birds.

The shelves of his home bowed with his many volumes of books about them. Among his slide collection: “Birds of the Texas Coast.” “Kansas Birds.” “Birds of Pakistan.” Birds are the subject of many of his pictures, the purpose of many of his walks and trips, and the meticulous citations on his slides reveal his admiration. His wife Mary modeled dead birds for his photographs, and he brought back to the United States stuffed corpses of his favorite birds of Pakistan, neatly labeled.

Quantifying bird love.