#167 Hihi

Notiomystis cincta
IUCN Redlist: Vulnerable
Location: Tiritiri Matangi Island, New Zealand
Time: 1410 NZDT March 9, 2012

The hihi, or stitchbird, is not, at first glance, a very striking bird. About the same size as a korimako, bell miner or a little smaller than a starling, they aren't particularly brightly coloured, the males a bit more so than the females.

They make a kind of tsit noise, particularly when a person is invading their space, from which they get their common name They also have a variety of other calls, but they are not reknowned songsters.

Once you look a bit closer though, they have some quite unique features and habits.

They were long thought to be in the honeyeater, Meliphagidae, and they do compete with the two New Zealand honeyeaters species, korimako and tui. They are the least dominant of the three, so when korimako and tui are abundant they forced to utilise lower quality food sources. Recent work has shown, however, that they are sufficiently distinct to warrant a family of their own, Notiomystidae, and that their closest relatives are the NZ wattlebirds, Calleiadae. 

Like the wattlebirds, the stitchbirds are also recovering from near-extinction. Formerly ranging across the North Island, they became extirpated everywhere except Little Barrier Island in the outer Hauraki Gulf. They are now being introduced to sanctuaries like Tiritiri Matangi, as well as predator-controlled areas on the mainland such as Ark in the Park. However, on Tiri, which lacks mature forest, they require supplementary feeders to get them through the year. Still, they are slowly but surely making a comeback.

Hihi preening and pooping, on a water trough on Tiritiri Matangi

But it's in their breeding behaviour that hihi are most unusual. Besides the common one male-one female thing, a female hihi may mate and nest with two or more males, or a male with multiple females, or indeed multiple males and multiple females all nesting together. They also have extra-pair copulation, which may be a male forcing itself on a female. And they do one thing no other bird is known to do: they sometimes mate face-to-face, which seems to be used during forced copulation. Below is a diagram from Castro et al. (1995) showing the variety of mating postures used:

References

Castro, I, Minot, EO, Fordham, RA, & Birkhead, TR. 1995. Polygynandry, face-to-face copulation and sperm competition in the hihi Notiomystis cincta (Aves: Meliphagidae). Ibis 138: 765-771