Snow D.W. & Snow B.K. (1973) The breeding of the Hairy Hermit Glaucis hirsuta in Trinidad. ARDEA 61 (1-2): 106-122

Observations were made on the social organization of the Hairy Hermit during 2+ years residence in Trinidad. They were made in conjunction with a more prolonged and intensive study of their breeding biology. A method of sexing most birds in the hand and many in the field was developed. The male Hairy Hermit occupies a section of stream or roadside where suitable nest-sites occur. Here one, two or rarely three females build their nests which the male helps to defend against other hermits. Pair bonds are established with these females. The courtship is mostly vocal with the male starting a phrase which is completed by the female. The same duet is uttered during a courtship chase. The male's role at the nest is apparently entirely defensive as he does not assist with incubation or feeding 1the young. Both members of the pair make the nest extremely conspicuous by frequently inspecting it while uttering a call, and by the female duetting with the male while she is at the nest. There is a male advertising song which is very rarely sung except by young unpaired males. It is probably homologous to the songs and calls uttered at singing assemblies by other male hermits. The Hairy Hermit's unusual social organization is interpreted as a consequence of its specialised nest-site. This is compared with the nesting of the two other hermits in Trinidad.