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 population of blue herons has quadrupled, and experts believe this number is sufficient for the species to survive in the wild. However, due to ongoing threats to their original habitat, the experts plan to relocate the blue herons 1,500 miles to a region where the common heron, a different species, thrives. The experts predict that this relocation will ensure the long-term survival of the blue heron.

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