Grey Warbler – Riroriro

Gerygone igata

Grey Warbler description

Grey Warblers are a small grey-brown bird with pale grey on the face throat and breast and an off white belly and under tail. Weighing about 6.5g, which is around one-third the weight of a mouse, this makes them one of New Zealand’s lightest birds.

The Grey Warbler is more often heard than seen, having a loud distinctive song, and tending to spend most of its time in dense vegetation. They are widespread through out New Zealand and relatively common

They are insectivores with a habit of hovering to pick insects and spiders from plants.

Nest description

A hanging enclose dome type nest usually concealed in dense vegetation, typically in the sub-canopy or canopy. The Interior is lined with soft material such as wool, hair or feathers.

Predators

One of the more unusual predators the grey warbler faces is the Shining Cuckoo. The shining cuckoo despite the Grey Warblers difficult to access nest. The cuckoos egg hatches before the grey warbler eggs, and once hatched the tiny chick actually pushes the remaining eggs or chicks out of the nest.
The cuckoo is much larger than the Grey warbler, requires a constant delivery of spiders and insects. Grey Warblers are dedicated parents though, and will feed the impostor chick for four weeks (they have even been seen hanging around their fledged chick to make sure it’s OK) before it flies off to join its fellow cuckoos in the Pacific.
In the September, 1991, Nortornis, the official publication of the New Zealand Ornithological Society, there is a photo of a cuckoo carrying an egg in its beak.

Threats and conservation

Although still common and not under threat they are preyed on by rats, possums, cats and mustelids.

Good pest control will ensure their future.