Records of What Birds Ate

Photo credit: Caridad Bojorquez/Proteus Gowanus

The Patuxent Wildlife Research Center houses a unique collection of records about avian diets. The records were compiled by federal scientists of the late 19th and early 20th centuries who dissected the remains of 230,000 birds to analyze their stomach contents. While most of the jars that once preserved the stomach contents are gone, the records of their contents remain on hand-written notecards.

The 230,000 notecards that accompanied the jars sit in a musty basement, mostly forgotten. And they too may face destruction. As with many other historical collections, the United States Geological Survey, which now runs the center, has neither the personnel to digitize the collection nor the space to archive it properly. “If I disappear,” Mr. Droege said, “there will be no one left to champion it.”

The scientists who helped gather the collection published hundreds of articles, and even a few books, describing the food habits of more than 400 native species. Dozens of other scientists have used the collection to study how birds’ feeding habits, distribution and abundance have changed over the past 100 years. The collection, undertaken to determine how birds were harming humans, can now be used to determine how humans are harming birds.

Dr. Haas is using the collection to study how agricultural practices have changed bird diets. She said that during the 1950s, farmers in the South were encouraged to replace native grasses with cool-season grasses, which could provide food for livestock earlier in the springtime. Now several grassland birds are declining, and Dr. Haas suspects that it is because of the switch to nonnative grasses.

Jean-François Ouellet, a doctoral student at the University of Quebec at Rimouski, is using the collection to study evolutionary relationships between a bird’s size and the quality of what it eats. He said the collection was helpful for its detailed information about hundreds of birds across the country over different time periods. 

It would be a shame if these historical records disappeared. Perhaps the cards could be scanned and entered by volunteers, in a manner similar to the existing North American Bird Phenology Program.