"Have you heard the ringing ‘more-pork’ call of our native owl recently? Luckily, for those of us living in Kaipātiki, our patchwork of native bush reserves provides ideal habitat for the morepork. I live near Verran Gully and regularly hear moreporks calling at night, so it is likely that they roost in the gully, although they defend territories of 3.5 to 7.8 hectares so may visit from other parts of Kaipātiki.
One night when I returned home after dark, a morepork called from a tree next to my driveway and I could just see its shadowy shape in the moonlight. Moreporks will roost in the same place on consecutive days but vary their roosting sites over time. Once I spotted a morepork roosting in a tree next door right by the footpath, but, unfortunately, my neighbour has since cut that tree down. Morepork habitat is unknowingly destroyed when land is cleared for housing, or large trees are removed to reduce shade or improve a view.
For many years the morepork (Ninox novaeseelandiae) has been New Zealand’s only native owl. Compare that with our Aussie neighbours - they have eleven! Until early in the twentieth century, New Zealand was home to the endemic Laughing Owl (Sceloglaux albifacies), but it became extinct. The little owl (Athene noctua), introduced from Germany between 1906 and 1910, lives only in the South Island. We do, however, now have another candidate for native owl status, the barn owl (Tyto alba), which has been breeding since 2008 in Kaitaia, Northland, and sightings have recently been reported in West Auckland. Perhaps barn owls will eventually make their way to the North Shore.
Moreporks, Hadfield Street, Beach Haven. Photo: S McGaffin
Most people are not aware of moreporks during the day when they are roosting, but many will have heard their signature call at night. Early settlers thought the double hoot of the owl sounded like ‘more-pork’ hence the name. Māori also gave it an onomatopoeic name, ruru. Moreporks make other calls too, including a deep, repeated ‘quor-quor-quor’ call, often made in the early evening before they fly off to hunt. Another call is a higher-pitched vibrating ‘cree-cree’ made during flight while hunting.
The morepork’s diet consists mainly of invertebrates, and they are said to be particularly fond of wētā. In the summer, ruru can sometimes be seen hawking for moths around streetlights. Unfortunately, sometimes similar behaviour in front of car headlights leads to fatal consequences. Their diet also includes mice, small birds, and lizards. Often the first meal supplied to chicks in the evening consists of one of these larger prey items.
Although we hear ruru call at night, they are difficult to spot because, owing to the soft surfaces and downy edges of their wings, their flight is silent. You can, however, spot them roosting during the day if you pay attention to the alarm calls of blackbirds. Blackbirds recognise ruru as predators and when spotted give a repeated warning ‘chink’ call. If you hear that call in your backyard, the predator is probably a cat, but if you are in native bush, there is a good chance the blackbird has spotted a morepork, and sometimes other small birds will join together to mob it. Generally, the drowsy morepork ignores the other birds and eventually they give up and move away, but, occasionally, they succeed in driving the ruru away. Moreporks roost in secluded, shady places usually in native bush. I have found they particularly like roosting on the lower dead fronds of ponga or silver ferns. Ruru are small owls, 29cm tall, and, with their brown and white speckled fronts, are well-camouflaged against the brown and white of dead ponga fronds, so you need to look carefully.
Moreporks, Birkenhead War Memorial Park. Photo: S. McGaffin
Ruru nest in hollow trees and benefit from the control of rats, stoats, and possums that target eggs, chicks, and nesting females. Another threat to their survival, specially in urban areas, is the felling of mature native trees; the trees that are most likely to offer hollow nesting sites. A recent Auckland Council report on tree cover reported that Kaipātiki was the only area that met the Council’s goal of having 30 per cent canopy cover. However, the Tree Council chairman, Sean Freeman, pointed out that the report hides that old and large trees are being lost and replaced with saplings. This trend could have serious implications for the survival of moreporks in urban areas such as Kaipātiki.
To maintain and increase our special population of moreporks we need to reduce the numbers of rats, stoats, and possums, and protect large, mature native trees. Planting native trees will provide habitat for moreporks in the future."
References: Heather, Barrie, & Robertson, Hugh. The Field Guide to the Birds of New Zealand. Penguin Random House, 2015. Moon, Geoff, New Zealand Forest Birds and their World. New Holland, 2010. nzbirdsonline.org.nz
This article was written by Sharon McGaffin, a volunteer active in the Verran Gully Halo, for the Halo Newsletter August 2020.