Each of the thousands of species of birds has its own language, so to speak, and this helps the females identify mates of their own species.
अंड्यांतील भ्रूण अंड्यांतूनच एकमेकांशी संवाद साधून, एकाच वेळी सर्वांनी सोबत बाहेर पडायचे, असे ठरवतात.