Natural Migration:
* Land Bridges: Some islands were once connected to the mainland by land bridges, which have since been submerged due to rising sea levels. Deer may have crossed these bridges before they disappeared.
* Natural Drifting: Deer, especially fawns, can sometimes be swept out to sea by storms or floods and end up on islands. This is less common but possible.
Human Introduction:
* Intentional Introduction: Humans have intentionally introduced deer to islands for hunting, wildlife management, or other purposes.
* Accidental Introduction: Deer can be transported accidentally on boats or other vehicles. This can happen if they stow away or are transported as cargo.
Factors that affect the likelihood of deer getting on an island:
* Distance from mainland: The further an island is from the mainland, the less likely deer are to reach it naturally.
* Ocean currents: Strong currents can make it difficult for deer to swim or drift to islands.
* Island size and habitat: Larger islands with suitable habitats are more likely to support deer populations.
* Human activity: Human activities like transportation and intentional introductions can significantly impact deer populations on islands.
It's important to note that deer introductions can have negative impacts on island ecosystems, as they can compete with native species and disrupt natural processes.