In many organisms, individuals that produce more offspring tend to have shorter life spans than individuals who aren't as productive. But how does this happen? Biologists examining data from an Indiana University decades-long study may have solved part of the puzzle.
Ellen Ketterson, Distinguished Professor in the IU College of Arts and Sciences Department of Biology, has been studying the dark-eyed junco (Junco hyemalis carolinensis), a common North American bird in the sparrow family, at the Mountain Lake Biological Station in Virginia since 1979. She and her research group have been making an annual census of the junco population at the station since 1984; their almost 40 years of consecutive data has been interrupted only once—in 2020 because of the COVID-19 pandemic. They return each year to determine who is still alive and what attributes the survivors have. Ketterson's nearly seamless records of individual birds' lives are crucial in understanding about the evolution and behavior of birds as well as ourselves.