<span> c. males use a protein to detect pheromones sent by females.</span>
Answer:
Birds have a different mating season this evidence will go against the argument and suggest that the birds are actually different species. Generally, two factors seasonal and behavioral identifies the differences among the species. Species generally interbred among the same population of species according to the season and hence they loose mating opportunities. Although being sexually compatible they do not interbreed. Behaviorally, a biological clock in species naturally sets breeding cycle according to the resources availability, suitable nesting sites and mating opportunities. Different species have different seasonal requirements to accomplish this.
