Monday, May 27, 2013

B is for BROLGA


The Brolga (Grus rubicunda) is a tall bird with a large beak, long slender neck and stilt-like legs.  The sexes are indistinguishable in appearance although the females are usually a little smaller.  The adult has a grey-green, skin-covered crown, and the face, cheeks and throat pouch are also featherless and are coral red.  Other parts of the head are olive green and clothed in dark bristles.  The gular pouch, which is particularly pendulous in adult males, is covered with such dense bristles to make it appear black.  The beak is greyish-green, long and slender, and the iris is yellowish-orange.  The ear coverts appear as a grey patch of small feathers surrounded by red naked skin and the body plumage is silvery-grey.


The feathers on the back the the wing covets have pale margins.  The primary wing feathers are black and the secondaries grey. The legs and feet are greyish-black.  Juveniles lack the red band and have fully feathered heads with dark irises.  A full-grown brolga can reach a height of 0.7 to 1.3 metres (2'4" to 4'3") and has a wingspan of 1.7 to 2.4 metres (5'7" to 7'10").  Adult males average slightly less than 7 kilograms (15 lb) with females averaging a little under 6 kilograms (13 lb).  The weight can range from 3.7 to 8.7 kilograms (8.2 to 19 lb).


Originally the brolga was known as the Native Companion and is a member of the crane family.  It has also been known as the Australian Crane, a term coined in 1865 by well-known ornithological artist John Gould in his "Birds of Australia".  The brolga inhabits large open wetlands, grassy plains, coastal mudflats and irrigated croplands and, less frequently, mangrove-studded creeks and estuaries.  It is less common in arid and semi-arid regions, but will occur close to water. It is found across tropical northern Australia, southwards through north-east and east central areas, as well as central New South Wales to western Victoria.  Although this bird is not considered endangered over the majority of its range, populations are showing some decline, especially in southern Australia, and local action plans are being undertaken in some areas.  It is the official bird emblem of the state of Queensland.  (It is not found in the area where we live in south-west Western Australia so it is not a bird I am familiar with).


Outside the breeding the season, brolgas form large family groups and flocks of up to a hundred birds.  These groups may be partially nomadic or may stay in the same area.  Some birds migrate northwards.  They are omnivorous (feeding on both vegetable and animal matter), but primarily feed upon tubers and some crops.  Some insects, molluscs, amphibians and even mice are also taken.


Brolgas are well known for their ritualised, intricate mating dances.  The performance begins with the bird picking up some grass and tossing it into the air before catching it in its bill.  The bird then jumps a metre (yard) into the air with outstretched wins and continues by stretching its neck, bowing, strutting around, calling and bobbing its head up and down.  Sometimes just one brolga dances for its mate; often they dance in pairs; and sometimes a whole group of about a dozen dance together, lining up roughly opposite each other before they start.


Brolgas probably mate for life, and pair bonds are strengthened during elaborate courtship displays, which involve much dancing. leaping, wing-flapping and loud trumpeting.  An isolated territory is established, and is vigorously defended by both partners.  The white (blotched with brown and purple) eggs are laid in a single clutch.  The nest is a large mound of vegetation on a small island in a shallow waterway or swamp.  Both adults incubate the eggs and care for the young birds.

A pair of brolgas building their nest, a nest with eggs, a close-up of an egg, and a brolga chick:





Brolgas in flight:

Within New South Wales, brolga numbers have been much reduced because of windspread drainage of suitable habitat for agriculture, land reclamation and water regulation, but birds are still common and widespread throughout Australia's north.

Aboriginal art depicting brolgas:

Brolgas on a 45 cent Australian stamp:


5 comments:

  1. I would LOVE to see a flock of brolgas dancing. When we went out to Tidbinbilla recently as well as the platypus I spent lots and lots of time looking at the brolgas. Beautiful birds.

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    1. As would I...I've seen the dance on film but would be great to see it first hand. I really must try and get to our zoo again now the cooler weather has arrived. I would love to see some of these magnificent creatures that are not endemic to WA. I believe you can hire gophers at the zoo which would enable me to get around (as long as I didn't run someone over!!).

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  2. The eggs are so pretty. In flight these birds look a lot like our herons.

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    1. I didn't delete comment to you Delores but had put a comment in wrong place. Those eggs really are rather special aren't they? I think herons and cranes have much in common as regards their appearance and I think the biggest difference is perhaps their varying sizes.

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