Seed Pellet Regurgitation by the Endemic Black Currawongs of Tasmania

posted in: Feeding-plants | 1

“Birds are known to regurgitate food for a number of reasons. Some regurgitate food to feed their young, others regurgitate undigested matter as pellets. While we are familiar with pellet regurgitation, this is more often known and observed in raptors, owls, kingfishers, shorebirds, gulls/terns, shrikes and crows. We are also more aware of pellet regurgitation involving undigested animal matter like fur, bones, feathers, teeth, etc. We are less aware of pellet regurgitation of seeds (Gill 2006) and this may be under-observed and under-valued.

“I was away in Tasmania for a 2 week break, as well as to enjoy birds and nature. I observed one species regurgitate seed pellets and went on to learn that this is a common behaviour for this group of birds. There are 3 species of Currawongs in Australia, a large black and white bird that is distantly related to the crows but ‘belonging to an Afro-Asian radiation of birds of superfamily Malaconotoidea’ (Wikipedia 2017). Of the three species, two occur in Tasmania, the Grey Currawong (Strepera versicolor) and the Black Currawong (Strepera fuliginosa); the latter is one of 12 Tasmanian endemic birds (Simpson & Day 2010; Pizzey & Knight. 2016).

Plate 1-Black Currawong-Strepera fuliginosa-adult-Mount Field, Tasmania-23rd February 2017 (1)

“I had an opportunity to see the Black Currawong often (above). This bird has a large diet range that includes small vertebrates (birds, rodents, lizards), insects and fruit. It often is found in mountainous regions feeding on the fruit of alpine shrubs and trees. One particular fruit that it eats, and is abundantly found, is the Mountain pinkberry (Leptecophylla juniperina) (below).

Plate 2-Mountain pinkberry-Leptecophylla juniperina-Mount Field, Tasmania-23rd February 2017 (1)

“On one occasion I observed it regurgitate a pellet of seeds (below). I saw the activity but only managed to document the tail end on camera. The pellet was dropped onto the branch of a tree (not within reach); …

Plate 3-Black Currawong-Strepera fuliginosa-adult-Mount Field, Tasmania-23rd February 2017 (1)

“…it was pink and comprised many seeds (below). I learned from our knowledgeable guide, Dr Andrew Hingston, that these birds often consume many fruits and keep the seeds in the crop or gizzard and regurgitate them as a pellet.

Plate 4-Black Currawong-Seed Pellet Regurgitation-Mount Field, Tasmania-23rd February 2017 (1)

“The image below shows a juvenile bird taking fruit.

Plate 5-Black Currawong-Strepera fuliginosa-juvenile-Cradle Mountain, Tasmania-26th February 2017 (1)

“This makes these birds important seed dispersers in forest areas. As Knowler 2016 states ‘The currawong … has an important relationship with the mountain environment, being responsible for the spread of seeds of alpine shrubs and trees. Among these are the mountain pink berry. The currawongs strip the shrubs of berries and then regurgitate the berry seeds, after devouring the flesh of the fruit.

“It is possible that some Malaysian birds are also important seed dispersers via regurgitation and keen observations may uncover this.”

Dato’ Dr Amar-Singh HSS
March 2017
Ipoh, Perak, Malaysia

References:
1.
Frank B. Gill. Ornithology. 3rd Edition. 2006
2. Wikipedia. Currawong. 2017 LINK.
3. Pizzey & Knight. The Field Guide to the Birds of Australia. Digital Edition 2016
4. Simpson & Day. Birds of Australia, 8th Edition. 2010
5. Don Knowler. Currawongs warn of winter. 11th June 2016 LINK.

One Response

  1. paula kraal

    I have an eastern currawong who drinks from my water dish and regurgitates the palm tree seeds into the dish after drinking.

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