Friday, July 22, 2016

Blue underwing plumage

The frame below is captured from a video taken 22 September 2006. It is of a wild male Western Ground Parrot, in Fitzgerald River National Park. The blue leading edge of the underwing is revealed. Most of the underwing is dove grey and the pale bar can just be seen. The video was filmed by Brent Barrett and is owned by the Department of Parks and Wildlife, Western Australia.

The following extract is taken from

Courtney, J. (1997). Age-related colour changes and behaviour in the Ground Parrot Pezoporus wallicus. Australian Bird Watcher 17, 185-191.

A courtship display of captive male Eastern Ground Parrots is described.

The epigamic (courtship) display was commonly observed during September and
October. The male stands upright and lifts the folded wings well away from the body
at the ‘shoulders’ (carpus) while the tips of the wings remain touching the back.
Presumably this is to display the soft sky-blue undersurface of the carpus, which in
bright sunlight contrasts with the green of the body. The long tail is pressed firmly
to the ground because of the upright body posture, and therefore cannot be fanned
in the manner of most platycercine parrots performing this ‘shoulder squaring’ display.
This posture is maintained for many seconds during which the bird may stand still,
or walk slowly around in small circles, calling frequently with a series of short whistles
usually described as ‘tee tee tee‘. Occasionally, a male perching on a branch vigorously
thrusts the body up and down several times by bending and straightening its legs,
while calling in a similar way.      

Sunday, July 17, 2016

Underwing plumage

The underwing plumage of two Western Ground Parrot specimens from the Western Australian Museum are shown below.

This is the adult female (roadkill), specimen no. 27142, shown in the previous blog entry. The blue-green marginal coverts are a colour not visible elsewhere on the bird's plumage.

This bird, specimen no. 27143, a male, found headless, lacks the blue-green marginal coverts, but this is perhaps an indication of a stage of moult. It is not a male/female differentiaton feature. However, the width of the pale underwing stripe may be.

The images were taken with permission from the WA Museum and are used here with permission.

Sunday, July 10, 2016

WA Museum specimens showing an external difference between male and female WGPs

 The photos were taken in December 2005, when the Western Australian Museum had only four Western Ground Parrot specimens.

The photos below were taken with permission from the WA Museum and are being published here with permission. No unauthorized use of the images is permitted.

Three of the specimens are shown here. The fourth lacks his head. All came from the south coast. From L to R: a juvenile female that was a casualty of a radio-tracking project in the Fitzgerald River National Park (well east of Albany) in 1988; a bird shot in Torbay (west of Albany) 1906 in mistake for a quail; an adult female killed by a vehicle on Springdale Road east of Fitzgerald River National Park in 1995. Although the central specimen was unsexed, a difference can be noted in the beaks. Further study of beaks of specimens from the Australian Museum and Museum of Victoria showed that the Torbay bird was a male.

Beaks of two of the specimens viewed from above showing the broad upper mandible ridge of the Torbay bird (top), and the sharper, narrower ridge of the Springhill bird. The Torbay specimen was used for display for many years.