In the Great Lakes region of North America, gray wolves and coyotes are similar species but do not mate because their breeding periods occur at different times of year. What type of speciation?

The females of two species of fruit fly Drosophila melanogaster and Drosophila simulans release slightly different mating hormones called pheromones, which are used to attract females

A type of isolation in which two populations become separated by a physical barrier such as a canyon, lake, river, preventing the two populations form interbreeding.

Tradescantia ohiensis, a plant also known as a bluejacket and its relative, T. subaspera have similar reproductive mechanisms but do not mate, as one species lives in the sun and the other lives in the shade.

A type of isolation in which two populations with complex courtship displays or rituals become different enough that they no longer respond to the other's actions.

The American toad (Anaxyrus americanus) and Fowler's toad(Bufo fowleri) live in the same area. However, the American toad mates in early summer while Fowler's mates in late summer.

The flashing pattern of the firefly (Lampyridae) is used to attract the opposite sex. Female fireflies only flash back and attract male fireflies who first signal them with species-specific pattern of light.

Albert's squirrel and the Kaibab squirrel are distinct subspecies that live on opposite sides of the Grand Canyon. They were once one species, but now differ significantly, including fur coloring.

Of the seven species of cicada (Cicadae), three follow a 17 year mating cycle, while 4 follow a 13 year cycle. In regions where their geographic range overlaps, their emergence coincides once in every 221 years. This happened in North America in 2015 and will not occur again until the year 2236.

Groups of the ancestor of modern day finches settles on different Galapagos islands. The islands were far enough away from each other that the finches from different islands rarely meet each other. Over time, they developed different mating habits and different beak sizes and shapes. They can no longer mate with each other.

A particular type of grass is growing near a mine. The ground over a wide distance becomes contaminated with heavy metal poisons. Some grass near the mine becomes resistant of the poison, but with tolerance becomes a change in flowering season. Because the poison resistant grass plant bloom and reproduce at a different time of year than the non-resistant plants living on non-contaminated ground nearby, they diverged and formed two separate species.

Hawaiian flightless crickets. Quickly over only 20 generations, crickets developed mutated flat wings that made them unable to call their mates. Scientists believe they developed these wings because the crickets who happened to have no wings were able to avoid a parasitic fly. The fly locates crickets by their mating songs. These Hawaiian island crickets came from a small population that broke off of a larger population of crickets from the mainland United States.