Behavioral Isolation — Definition & Examples

A population of birds lives in a forest. Some of the birds wake up in the morning, while some other ones wake up at night. Over time, the birds that wake up at night don't respond the same way to the mating dance of the morning birds. Eventually, their mating seasons also change, with the morning birds mating in the spring and the night birds mating in the fall. What is the correct sequence of isolations for these birds?