A few years ago, the population of the rare blue heron was critically low, prompting wildlife experts to establish a breeding program in a protected area. Since then, the blue heron population has quadrupled, and experts believe this number is sufficient for the species to survive in the wild. However, due to ongoing threats to their habitat, the experts plan to relocate the blue herons 1,500 miles to a region where the common heron thrives. They predict this move will ensure the long-term survival of the blue heron.

Which of the following, if true, undermines the experts' prediction?