For many species the breeding season is over and they are moulting rendering them unable to fly. Thats good news for Anja, because she needs blood and feather samples from the coots to perform an isotope analysis. Together, the researchers drive the birds in the direction of the strategically placed duck traps. They also need to examine the isotopic signature of the food they suspect to be the coots principal food, low-light algae and zebra mussels. They are considerably easier to catch in comparison to the coots.