Auckland Island Rail
Lewinia muelleri
Gruiformes Order – Rallidae Family
INTRODUCTION:
The Auckland Island Rail is endemic to the Auckland Islands, 460 kilometres S to New Zealand.
This nearly flightless small rail is the only resident rail on these islands. It is very difficult to see as it spends all its time in the vegetal cover.
This species occurs on predator-free islands and formerly, it was probably living on all the islands of this group. But the changes of vegetation caused by pigs and predation by introduced cats have eliminated the rail from the main Auckland Islands. This bird is very secretive like all Rallidae, but it is quite vocal and more often heard than seen.
DESCRIPTION OF THE BIRD:
Biometrics:
Length: 18-20 cm
Weight: 90-100 g
The adult has reddish-brown head and neck, but male and female may differ in extent of this colour. The upperparts are olive-brown with sparse dark streaks. On the upperwing, we can see restricted sparse barring on wing-coverts and reduced spots on primaries.
On the underparts, the breast is grey. Flanks and undertail are barred black-and-white.
On the head, the lores are blackish. The bill is red with pale grey tip. The eyes are dark brown. Legs and feet are greyish-brown.
Both sexes are similar but the female may appear slightly duller.
The juvenile has dark lores and ear-coverts, and pale streaking on crown and upperparts.
RANGE:
The Auckland Island Rail occurs on Adams and Disappointment Islands (about 10,300 ha) in the Auckland Islands group.
HABITAT:
The Auckland Island Rail is often hidden among the dense vegetation of about 1 metre high such as tussocks, megaherbs and sedges, ferns and low woody shrubs. It can be seen from sea-level up to 450/500 metres of elevation.
However, the rails of Adams Island can sometimes frequent short forest (2, 5 metres high) with dense understorey of ferns and sedges.
CALLS AND SONGS:
The Auckland Island Rail gives typical, loud, descending “kek-kek-kek” calls (1 per second) and also a sharp, whistle-call repeated about 50 times in a 10-12 seconds period.
We can also hear a variety of quiet calls, usually grunts and clicks.
BEHAVIOUR IN THE WILD:
The Auckland Island Rail’s diet is poorly known but it probably feeds mainly on invertebrates. It forages from dawn to dusk and probably after darkness comes.
This species is territorial and monogamous. Information is lacking about the courtship behaviour, but we can suggest that during the displays, the male moves with raised wings and tail, in order to enhance the barred pattern of the flanks. Displays are accompanied by calls.
The Auckland Island Rail is sedentary in its reduced range.
This species can flies, but it is rarely seen in flight.
REPRODUCTION OF THIS SPECIES:
The breeding season occurs in spring and summer, between October and December.
From an observation of a nest in wetlands, the nest is built among dense vegetation. It is made with woven grasses and sedges, at about 20 centimetres above the ground. It is sheltered by overhanging vegetation, with an entrance runway.
The female lays two eggs. The incubation period is unknown, but it might be similar to that of the Lewin's Rail (Lewinia pectoralis), which lasts 19-20 days.
PROTECTION / THREATS / STATUS:
The Auckland Island Rail is not currently threatened as it is living on predator-free islands.
Some mammals might cross the narrow area between Auckland Island and Adams Island, and threaten the rails living there.
The Auckland Islands are nature reserves with controlled and limited access. The population is currently estimated at about 1500 birds on the two islands. This species is naturally uncommon and difficult to find.
The Auckland Island Rail is listed as Vulnerable due to its very small range, but currently, the population appears stable.
Fr: Râle des Auckland
Ang: Auckland Island Rail
All: Aucklandralle
Esp: Rascón de las Auckland
Ita: Rallo di Auckland
Nd: Müllers Ral
Sd: Aucklandrall
Text by Nicole Bouglouan
Sources:
HANDBOOK OF THE BIRDS OF THE WORLD Vol 3 by Josep del Hoyo-Andrew Elliott-Jordi Sargatal - Lynx Edicions - ISBN : 8487334202
BirdLife International (BirdLife International)
New Zealand bird status between 2008 and 2012
Te Ara – The Encyclopedia of New Zealand
Wikipedia, the free encyclopaedia