One prezygotic reproductive barrier is temporal isolation. Temporal isolation means 'isolated in time,' so this is a mechanism that prevents species from mating because they breed at different times. These differences can be time of day, season, or even different years.
Reproductive isolation is why different species of animals and plants are not able to interbreed with one another. Speciation, or when one species splits into two or more species, is to be blamed for many cases of reproductive isolation within similar types of organisms.