The regent honeyeater is a critically endangered species from Australia. Because there are so very few birds left, they are losing their song culture, as they are not enough elders to teach the young. This causes problems in mating rituals.

Source:
Loss of vocal culture and fitness costs in a critically endangered songbird
Ross Crates , Naomi Langmore , Louis Ranjard , Dejan Stojanovic , Laura Rayner , Dean Ingwersen and Robert Heinsohn