a. What might be the adaptive benefits of red crabs migrating at the same time? (think about what happens to individuals that miss the event, or travel separately)
The timing of spawning is the only certain and predictable part of the whole migration; all other stages of the migration will vary with the prevailing weather.The migration of the red crabs occurs at the end of the dry season and is triggered by the arrival of the monsoon rains, but the breeding activities are also synchronized with the lunar cycle.
The crabs' breeding timetable is fixed around the phases of the moon. Spawning (the dropping of their eggs into the sea) must occur before sunrise on spring tides during the last quarter of the moon, regardless of any other factor.
The crabs will start their migration if there is enough time for them to complete their downward migration, mate and develop eggs before the next suitable spawning date.
Get Answers For Free
Most questions answered within 1 hours.