Laura Erickson's For the Birds

While I was rehabbing the first nighthawk I ever handled in the late 1980s, I thought it had an intestinal disorder or a parasite. Most of the time it produced normal bird droppings, but once a day it produced a yucky brown, messy, smelly dropping. When I discovered this with the first nighthawk I cared for, I didn’t know what to do, but the bird did okay, but then every nighthawk I worked with turned out to be the same.

I was mystified, but I researched the issue and developed a theory, guessing that nighthawks must have caeca, two blind offshoots where the large and small intestines meet where our appendix is. Ruffed grouse caeca grow huge in winter when they’re digesting woody buds on trees, but they shrink in spring and summer when the grouse are eating berries and insects. A bacterium in grouse caeca produces an enzyme that breaks down cellulose, allowing the birds to extract nutrition from woody tissue during the time of year when little else is available for them. The smelliness is due to the bacteria. I reasoned that chitin in insect exoskeletons is no more digestible than cellulose and wondered if nighthawk caeca could harbor a bacterium that produces an enzyme to break down chitin.

I found a morphology textbook by Bedard from 1898 that verified that nighthawks do in fact have caeca. I dissected one poor bird that had died en route to my house for rehabbing, and sure enough, I was pretty sure I could even find them. Then when I attended the next American Ornithologists Union meeting, I asked every ornithologist who’d presented a paper on physiology the question. Not one of them had a clue, but to a one they told me to find Gary Duke. “Gary knows everything about bird digestion.” “No one knows more than Gary Duke about bird poop.”

Gary wasn’t at the meeting but was about as close to home as a research ornithologist could be, right down at the University of Minnesota in St. Paul. I called him as soon as I got home, and when I told him how I’d puzzled through the question, he grew increasingly excited, saying few people think much about bird digestion or bird droppings, and he was thrilled to find someone who found it so fascinating. We were kindred spirits.

He said no one ever studied nighthawks’ cecal function before, but he was sure I must be right, and on the spot asked if I wanted to prove my theory as his Ph.D. student. I was dubious. I didn’t want to kill or hurt any nighthawks to study them and knew that just about all physiological research is invasive. But Gary said he felt sad whenever he thought about the screech owls and kestrels he’d had to sacrifice doing his own research, and thought developing a line of research about this question that did not involve hurting or killing birds would be novel, interesting, and ultimately valuable, so he said he’d entirely support me on this.

I brought three nighthawks down to the cities for Gary and me to observe digesting barium-laced food, and we radiographed the entire process. He and I are probably the only people on earth ever to have observed this firsthand.* Gary said I was the world authority on nighthawk digestion and physiology, though he added that people weren’t exactly lining up to claim the distinction.

I had small children at the time, so worked on and off on the project until a few years later when Gary called me to tell me he had to retire after being diagnosed with early Alzheimer’s disease. I cried when he told me. He apologized over and over that he wouldn’t be there for my Ph.D. work, but I hadn’t been crying about that. What did that matter in the face of the much larger tragedy?

My loss of my Ph.D. research project is minuscule compared to my personal loss of this extraordinary man whom I not only admired but loved for his passion for research, his brilliance, and his compassion. My loss pales in comparison to what the world lost when Gary’s memory failed.

Gary Duke was well known and respected in the ornithological world, with unique passions both for physiology and for developing cool contraptions to study it. He was also a great conservationist, and his family and friends lost all that and more. Gary’s face lit up every time he talked about his wife and his two daughters, and he talked of them often. Imagine what they’ve suffered watching this loving, brilliant, compassionate man slowly slip away.

Gary Duke died last week. As co-founder of the Raptor Center, it was entirely fitting that a Great Horned Owl perched on a Raptor Center representative’s arm presided over the funeral. I’ll never finish my Ph.D. and never be called Dr. Laura, though as Gary noted the world has one too many of those already. But Gary gave me a lot more than a Ph.D., and I’ll always be proud of the fact that for one brief, shining moment I was his student.

*After Gary developed Alzheimer’s, he lost the videotape of that work.