A page from my field notebook from 28 June 1994, from Sector Santa Rosa of the Area de Conservación Guanacaste, Costa Rica. This is what I used to do before digital photography. This shows the tree Cordia alliodora, identified for me at the time by Roberto Espinosa (RE). Cordia stems are swollen and contain ants, of several species but mostly a small ant with a flattened head, that uses its head to block the entrance to the cavity where they nest. I've since learned that this is the obligate Cordia specialist ant, Zacryptocerus setulifer (Emery), now known as Cephalotes setulifer. (According to John Longino "The most ubiquitous inhabitant of C. alliodora is Zacryptocerus setulifer (Emery)...Nearly every C. alliodora population I have examined in Costa Rica has had Z. setulifer in some of the nodes.")
Newly built nest in Gorse bush
Pic 2 as it appears from the track (Back of nest the entrance is on other side)
Found under a latch tree after a big storm. All the same construction.
Baldwin Ave Train Station, Mount Albert, Auckland.
Correct me if I'm wrong, but looks like the tail feathers of a Long-tail Cuckoo to me. Perhaps got in a scruff with some territorial Tui?!