Complex sentence: The seeds of "Capsicum" plants are dispersed predominantly by birds: in birds, the TRPV1 channel does not respond to capsaicin or related chemicals in birds (avian vs mammalian TRPV1 show functional diversity and selective sensitivity).
Split into simpler sentences: The seeds of "Capsicum" plants are dispersed predominantly by birds. The TRPV1 channel to which capsaicin binds does not respond to capsaicin and related chemicals in birds (avian vs mammalian TRPV1 show functional diversity and selective sensitivity).