Answer: C. A natural disaster, such as a hurricane, struck the island.
A limiting factor is a resource or ecological condition because of which growth and distribution of an organism or group of organisms living in an ecosystem limits. A limiting factor can be of either physical or biological in nature. A limiting factor restricts organisms from occupying their fundamental niche. Examples of limiting factor are resources, stress due to overcrowding, disease or parasite and a natural disaster. According to the condition mentioned natural hazard can be the only limiting factor to limit the population at such considerable rate. Natural disaster is a physical limiting factor which has catastrophic impact of populations of different species living in an ecosystem. It has the potential to wipe out several inhabitants in one drastic event. Therefore, a natural disaster, such as a hurricane, struck the island can be a most likely explanation for the changes that the scientists observed.