Collaborative Research: LTREB: The importance of resource availability, acquisition, and mobilization to the evolution of life history trade-offs in a variable environment.

In biology, there is a basic idea that organisms can only spend a unit of energy once. More energy spent on one aspect of life means that less energy is available to spend on other things. This leads to the expectation that organisms that are better at one thing should be worse at something else.

The problem is that most of the time when researchers study organisms in nature they find that individuals that are better at one thing are also better at others. One explanation for this is that some individuals just have access to more energy overall – so they can spend more energy on both aspects of life. This idea has been hard to study in nature because it is very hard to measure how much energy individuals have.

In this project, researchers will use a long-term study of wild red squirrels to test whether differences in food availability affect how individuals perform in different aspects of their life. The researchers can do this because they can track squirrels through their lifetime and because they can measure how much food squirrels have stored. This is important because this is one of the rare situations where it is possible to measure how much food individuals have and to see how they use this food to fuel different aspects of their life.

This research will also help us to understand how wild animals respond to changes in their environment, which will help us to predict their ability to cope with future changes in the environment. This long-term field study will also provide important training to undergraduate and graduate students while building stronger connections and capacity within local communities near the field location.

In addition to making their data open to the public, the researchers will also develop tools to help the public explore the data collected and to use the data to answer their own questions.

More specifically, this project will test the hypothesis that fundamental life history trade-offs, measures of natural selection on life-history traits and measures of the genetic basis to life-history traits are confounded by individual variation in resource availability. The researchers can quantify the amount of stored food for all individuals in the population to test these fundamental questions.

Documented ongoing changes in the availability of food in this population have the potential to not only change the average amount of food available to individuals but also the amount of variability among individuals in food resources. This means that future environmental changes could reveal stronger trade-offs and expose the genetic basis of life history traits to natural selection.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.