Long time we suspected that only Agapornis roseicollis is transporting nesting material between the feathers on her rump or upper tail. But later we also observed this behaviour with Agapornis canus. (We published pictures of a female Agapornis canus that was transporting nesting material between her feathers, in my book Love birds, Owner’s manual and reference guide (2005) on page 16.)
Now, in Singapore, also blue-crowned hanging parrots [Loriculus galgulus] have been observed utilising the leaves of mango and longan trees as nesting material. The parrot was using his bill to tear small pieces of leaf from the leaves proximal to his perch. After tearing off a small piece of leaf, the parrot proceeded to tuck it among the red feathers on his throat. [1]. So we can conclude that this behaviour is not exclusive for Agapornis spp.
My Blue-crowned hanging parrots do the same with bits of wild grasses and also with the halves of sunflower seed hulls.