University of Delaware researcher Megan Cimino recently led a team of oceanographers that watched Adélie penguins and gentoo penguins on the West Antarctic Peninsula to see if they were competing for the same food resources, and whether this might be exacerbating the Adélie population decline.

"We set out to explore whether the Adélies and gentoos were eating out of the same lunch box, so to speak,” explained Cimino, a doctoral candidate in UD’s College of Earth, Ocean, and Environment.

To test whether the species were competing, the researchers tagged penguins with small satellite transmitters and depth recorders to track where the penguins went and how deep they were diving. The tags were attached to a different penguin every three days over the month-long 2011 study which took place during the chick-feeding phase of the breeding cycle when adults are feeding chicks and the parental foraging ranges of both species overlap. Each penguin completed a few foraging trips and hundreds to thousands of dives while tagged.

Additionally, the research team used an autonomous underwater vehicle (AUV) called a REMUS to sample the water where the penguins were foraging, something few researchers have done before. The REMUS provided important measurements on temperature, salinity and how much light was in the water (important for visual predators like penguins).

It also measured the amount of phytoplankton and krill, the main food source for both penguin species, present in the water, systematically allowing the researchers to measure multiple levels of the food chain in the same study, from phytoplankton to krill to penguins.

Cimino is available for interviews.