Question

Two closely related birds sing slightly different songs to attract a mate. If

the song is not right, the mate won't be attracted. These birds likely
remain as separate species due to
O reduced hybrid viability.
O behavioral isolation.
geographic isolation.
O
O temporal isolation.

Answer 1

Behavioral isolation

Step-by-step explanation:

Temporal isolation prevents different species from breeding with each other due to different mating times.

Geographic isolation is when a physical/geographical barrier prevents species from breeding with each other.

Reduced hybrid viability is when offspring from the result of two different species mating has a lower chance of survival.

Behavioral isolation is when different species experience reproductive isolation due to differences in mating rituals and/or signals.

Behavioral isolation makes the most sense here.