New reports on ruru nesting and Island conservation

Date posted: 02-Oct-2017

Two new reports have been added to the website. The first gives details of a summer students..

2018 calendars now available

Date posted: 27-Sep-2017

Our latest calendar, beautifully illustrated with images taken on the Island, is now available fo..

Guided walks for photographers

Date posted: 21-Jun-2017

For a wonderful day of wildlife photography please join us on Tiritiri Matangi Island for a Ph..

Ferry discounts for Supporters

Date posted: 18-May-2017

Tiritiri Matangi Island, the perfect winter's day trip. The birds are at their best, warm up w..

More kiwi for the Island

Date posted: 04-Apr-2017

In 1993 and 1995, sixteen little spotted kiwi were released on Tiritiri Matangi Island. The ma..

2017 Photo Competition

Date posted: 22-Mar-2017

It is that time of year again when we are looking for entries for our photo competition (and phot..

The 2017 concert

Date posted: 05-Feb-2017

This year's concert promises to be another wonderful and unique experience. Click here (/concert-..

Shorebird Film Festival at Devonport

Date posted: 26-Oct-2016

Click here (/miscellaneous documents/DevWaderFilms.jpg) for details of a forthcoming film festival c..

Extra Dawn Chorus Trip

Date posted: 20-Oct-2016

Stop Press: Extra Dawn Chorus trip now scheduled for Thursday 27th October 2016. ..

2016 AGM

Date posted: 06-Sep-2016

The 2016 AGM was held at the Kohia Centre at 7:30 pm on Monday 19th September. Click here (/..

Australasian Harrier

Scientific name:

 Circus approximans 

Maori Name:

 Kahu

 

 

Conservation status

 Native. Not threatened

Mainland status:

 Widespread and locally common

Size:

 55cm, 650g (males) 850g (females)

Lifespan:

 Oldest recorded in NZ: 18 years

Breeding:

 September - December

Diet:

 Carrion and live prey


The Australasian harrier, known as the swamp harrier in Australia, is a large brown raptor with long fingered wings held in a v-shape, and a long slightly rounded tail. The very dark brown juvenile has a prominent white patch on the back of the head, brown upper tail and brown eye. The adult has a distinctive pale facial disc with head and upperparts dark brown. Underparts are reddish brown streaked dark brown and underwings are barred at the tips. The light brown tail is barred dark brown and the upper tail is white. Males have a yellow eye and the females a pale yellow eye. As they become paler with age some very old males can be seen with frosty-grey upperparts, pale buff underparts and white underwings.

Harriers are usually silent except for an occasional whistle, but in the breeding season during display flights the male utters a high–pitched ‘kee-a’, to which the female responds with a ‘kee-o’.

Harriers hunt by day, either by slowly quartering the ground or by hovering and then dropping vertically to catch their prey in their sharp  talons. They eat carrion (sheep, possums, hedgehogs, waterfowl and other game birds) as well as catching live prey (mainly small mammals, especially rabbits, hares, hedgehogs, rats, mice, birds, ducks and eggs, frogs, fish, lizards and large invertebrates such as grasshoppers and crickets).

Breeding is between September and February. The bulky nest of sticks, bracken, manuka, grasses and rushes is usually sited on the ground in raupo swamps, bracken-fern, clumps of pampas or on road verges. Over a period of days 3–5 off-white eggs are laid and incubated by the female for 31–34 days. The eggs hatch over a few days, and the youngest chicks often don’t survive. Although the male gathers food for the female and chicks, only she feeds the chicks. They fledge at 43–46 days old and finally disperse about seven weeks after fledging.

It is not unusual to see harriers soaring over Tiritiri Matangi in search of prey. They have large territorial ranges and frequently visit from the mainland. They have been known to take brown teal/pateke and kokako. Harriers only take prey that is on the ground, on a pond or in a tree, so a bird’s best way of escaping a harrier’s talons is to take flight. Flocks of birds have been observed mobbing harriers as they hunt and occasionally are successful in chasing them out of an area.

Learn more about the Australasian harrier at New Zealand Birds Online.

Photography by Max McRae ©

References: Heather, B.D.; Robertson, H.A. 2000 The Field Guide to the Birds of New Zealand. Auckland, Viking. Moon, G The Reed Field Guide to New Zealand Birds.