Tildes Talks - The Shining Cuckoo
The shining cuckoo or pīpīwharauroa is a migratory bird and makes an approximately 4700 km journey to and from Pacific islands such as Fiji, Tonga, and Samoa every year. Not bad for a bird that weighs around 23g! They live in Aotearoa from September to March each year but like many kiwis, will overwinter in the Pacific Islands.
The shining cuckoo or pīpīwharauroa is a bird that many people have heard but never seen, which is a shame because they are beautiful. The bird’s call is very distinctive with repeated rising notes usually followed by repeated falling notes. You can listen to the call here https://www.nzbirdsonline.org.nz/species/shining-cuckoo
The song is incredibly loud and leaves you craning your neck to get a glimpse of the singer. However, pīpīwharauroa are incredibly well camouflaged, with a green and bronze iridescent back that blends in well with the surrounding foliage. Their bellies are barred black and white, which is difficult to pick out when looking at them from below, blending in with twigs and leaves silhouetted against the sky.
The extraordinary migration is far from the strangest thing about the pīpīwharauroa. What really stands out is their lazy parenting! All species of cuckoo are brood parasites, which means that rather than building their own nest and raising their own chicks, they hijack another bird's nest and force those parents to raise their chicks.
The host for the pīpīwharauroa is the grey warbler or riroriro. The riroriro is tied for the smallest bird in Aotearoa with the rifleman, both weighing around 6 g.. The mother cuckoo will replace a single warbler egg with an egg of her own. When the cuckoo chick hatches, it will push any nestmates, be they eggs or chicks, out of the nest and be raised by its new warbler parents. The riroriro parents appear to be none the wiser and will happily continue to feed their imposter child, even when it grows to many times their size! Rirorio can still thrive however, as they usually lay several clutches of three to five eggs per season, and get one clutch away before the cuckoos arrive, so many nests will not get parasitized
The pīpīwharauroa has another superpower: the ability to digest toxic caterpillars. Some caterpillars have hairs running along their bodies, which break off when eate,n exposing a poison gland. The cuckoo has a thick mucus layer in its gizzard. The hairs break off inside their gizzard and are absorbed by the membrane, which is later regurgitated along with the hairs. The pīpīwharauroa has been observed catching hairy red admiral butterfly caterpillars. These caterpillars live in the native tree nettle or ongaonga, which has a sting similar to a bee. The plucky pīpīwharauroa was impervious to the toxin of the plant and the caterpillars. They have also been observed eating monarch butterfly caterpillars which are also toxic due to their diet of swan plant. It is not known how they survive the toxin which will cause heart failure in many birds.
The pīpīwharauroa is of great significance to many iwi, and traditionally, its arrival back in Aotearoa was one of the first signs of spring and the signal to prepare the ground for kumura harvests. Additionally, many ancient Polynesian navigators used bird migration patterns to find land around the Pacific. It is thought that following the pīpīwharauroa may have helped people first discover Aotearoa.
Sadly, the only time many people actually see the pīpīwharauroa is after window strikes. The best way we can help look after the pīpīwharauroa is to have decals on our windows. Nearly transparent window decals can be purchased from Waiheke Native Bird Rescue or online and will help many other bird species as well.
