Natal Homing - Evolution

Evolution

It has been studied and recorded by scientists that at a beach in eastern Mexico, where Kemp’s ridley turtles nest, a navigational error from the inclination angle over a period of one decade would lead the turtles only within an average of 23 kilometres (14 mi) from their natal region. Other locations resulted in navigational errors of over one hundred kilometers in the same period of time. Results from this study show that the navigational tool of geomagnetic imprinting is believed to only navigate the marine animals close to where they were born and then the animals rely on chemical cues of the tributaries and rivers to direct them to back to their birthplace.

These navigational errors have actually strengthened the evolutionary trait of natal homing for marine animals by resulting in some animals straying from their birthplace. Most animals return to their natal region because they know it is a safe place to lay their eggs. These regions will usually have few predators, the correct temperature and climate, and will have the right type of sand for turtles because they cannot lay eggs in wet and muddy environments.

The few animals that do not return to their natal region and stray to other places to repoduce will provide the species with a variety of different locations of reproduction, so if the original natal locations have changed, the species will have expanded to more places and will ultimately increase the species' survival chances.