What is an example of prezygotic isolation?

Prezygotic isolation refers to mechanisms that prevent mating or fertilization between species before the formation of a zygote. Seasonal mating differences between species is a clear example of prezygotic isolation because it involves temporal factors, where different species breed at different times of the year or on different seasonal cycles. This timing difference reduces the chances of mating occurring between the species, thereby preventing fertilization from taking place.

In contrast, hybrid sterility and reduced viability of hybrid offspring occur after fertilization, classifying them as postzygotic isolation mechanisms. Gametic incompatibility, which might also be considered a form of prezygotic isolation, specifically deals with issues at the gametic level but does not address the broader timing aspects that seasonal mating differences capture effectively. Thus, while gametic incompatibility is a valid prezygotic example, the seasonal mating differences provide a more comprehensive view of how species can remain reproductively isolated before any zygote formation is even attempted.