The study looked at how the population size of barnacle geese in the Arctic affects their survival and reproduction rates. They found that as the population grows, the geese have fewer babies, which slows down the overall population growth. However, the number of adult geese didn't have a big impact on survival rates. As the population gets closer to its limit, adult survival becomes more important for the population to keep growing. This is different from other birds that rely more on young birds surviving to control their population size. Overall, the study shows that barnacle geese in the Arctic are more focused on reproduction to control their population size.