In Michigan, two different species of gray treefrogs, Hyla versicolor and Hyla chrysoceles, can exist in the same pond at the same time. The two species are anatomically very similar, but their mating calls differ. How would you describe the existence of such similar species in the same location?

They are sympatric species.

Explanation:

Sympatric speciation is the presence of two species with same surviving ancestral species in the same geographic area. Sympatric species have numerous characteristics that are common in the same geographical area. They have same evolutionary path therefore they are anatomically similar too.

This is an example of sympatric frog species

Explanation:

Sympatric species are those species that are found in the same habitat and are morphologically similar (even indistinguishable sometimes); however, these species have reproductive barriers and they are therefore genetically distinct