A key concept to teach in undergraduate ecology courses is that species interactions such as competition influence the distribution and abundance of species. The goal of this project was to design and implement a game activity to help undergraduate biology students identify the likely outcomes of competitive interactions (e.g., coexistence vs. competitive exclusion) given information on species’ habitat use (e.g., generalization vs. specialization), resource value, and species’ relative competitive abilities.
Students competed for limited food resources as members of either the red or blue species. Students bid tokens on red resources worth 1-3 points each and blue resources worth 3-6 points each. In both scenarios described below, each species had a competitive “tie-break” advantage over the other species in resources matching their species’ color (e.g., blue species members could win blue resources by matching rather than exceeding red species member’s bids). In Scenario 1, both species were generalists (i.e., they could bid on resources of either color). In Scenario 2, the blue species specialized on blue resources (i.e., could not bid on red resources), whereas red species members remained generalists. Students compared the number of points earned by each species at the end of three rounds of each scenario.
Results/Conclusions:
In Scenario 1, in which the blue species had a competitive advantage in resources that were worth more points, the blue species greatly outscored the red species. Students predicted that the blue species would competitively exclude the red species over time. In Scenario 2, although the red species could bid on either color of resource, they bid mostly on low-value red resources, due to the competitive superiority of the blue species in blue resources. Given that blue species members could not bid on red resources, though, the red species maintained low point levels by bidding mostly on red resources. Students predicted that over time in this scenario, the two species would coexist due to niche partitioning.
We effectively demonstrated potential outcomes of interspecific competition in the game by manipulating the rules governing habitat use (e.g., whether species act as generalists or specialists on particular resources) and competitive ability in each game scenario. Next we will investigate whether students were able to translate what they learned in the game to examples involving real species. This game provides an engaging framework upon which instructors can build for students to explore how resource and species characteristics influence competition outcomes.