Asessment of Pair Quality: Assignment #6
In lecture, you learned that we might expect "mutual" mate choice in a genetically monogamous species. In Herring gulls and Great Black-Backed gulls, males and females can vary substantially in mate quality and both must provide a great investment if they are to successfully raise their chicks. Thus, choice of a mate should be important. Unfortunately for us, the gulls have already made their mate choice decisions. We can not know at this point what criteria each sex thought were important. However, we can make an evaluation of their decision by looking at how well the pair performs during the most crucial part of nesting cycle, i.e., while chicks are still highly dependent on parent care. Parental attendance, to protect chicks from predation, and foraging, to provide nourishment for growth, are essential for success. Indeed, when one of the members of a pair is removed there is a very high failure rate among the single parents. In the suggested readings Responses to Mate Loss the results are uniformly poor --100% failure. Even when the two parents are on the nest, reproductive success is variable. The required reading A Measure of Parental Quality? takes a close look at the characteristics of "successful parents" versus "failed parents". Your assigment, Assessment of Pair Quality, is designed to look at some of the attributes that are important to prevent mortality. We will examine whether these same attributes are important for gull success on Appledore Island. Our data will only provide a 'snap shot' in time of how well our gulls might be performing. We will use a pooled class data set to help us draw conclusions about what makes a successful versus poor mated pair.
Read the assigned paper prior to conducting the exercise. You can use the same pair territory you used for the exercise on territorial defense.
Consider the ways you might extend this exercise to make your individual project.
Email or talk with your instructors with questions you might have about the exercise or the paper you've read.