Your question is rather unclear but from what I can tell either there were not an even amount of Petri dishes or some of them were left open while others were not.
Answer:
Over population
Explanation:
With the coyotes gone, they're prey will have little to no predators. Without their numbers decreasing as quickly (because of the coyote population drop) they will be able to repopulate quicker and less of them will die. This will lead to over population.
