Brown and colleagues studied competition among small rodents in the Chihuahuan Desert near Portal, Arizona. To assess whether interspecific competition had any influence on population size of these rodent species, they conducted a:

The correct answer would be - Species removal experiment and the DeWitt Replacement experiment.

Explanation:

The competition can be increase for the various resources such as habitat, nutrients, water, and many more due to the territorial behavior of interspecific species.

The influence of the interspecific behavior such as competition influences on the population size of the species, two important tests are used are species removal experiment, and DeWitt Replacement exp commonly eriment.

Thus, the correct answer is - Species removal experiment and the DeWitt Replacement experiment.