June 2014

A question of confusing Corvids

We thought the black birds we were seeing in and around Brisbane were Crows but we were told by some that they are Ravens. Are these just different names for the same bird or are they different species?

Answer

Torresian CrowThe short answer is Ravens and Crows are different species they are however members of the same family Corvids.
Australia is home to six Corvids, three Crows and three Ravens. Generally speaking the physical similarities between species of Corvids can make them difficult to tell apart. Knowing their distribution can sometimes help identify the different species though this cannot always be relied upon.

Australian Raven

In and around Brisbane the Corvid that you would be seeing is the Torresian Crow Corvus Orru. This bird has adapted very well to living in the ever changing city and suburban environment. If you travel a little further inland of the Queensland coast the Corvid you would most likely come across is the Australian Raven Corvus coronoides.

If you were to see the Australian Raven and the Torresian Crow side by side, how would you tell the difference between the two?

The two species are similar in size though the Australian Raven at up to 52cm is marginally larger (Torresian Crow 50cm). Possibly the most obvious difference can be noticed when the birds call. The Australian Raven has a very large throat bulge, its hackles (feathers that stick out) extending quite a way out from its throat almost like a beard. The Torresian Crow on the other hand has only a slight bulge at its throat when calling and the throat hackles are less prominent if visible at all.

The calls themselves are different. The Torresian Crow emits a series of short rapid notes that may end with one or two longer notes   ‘arrk,arrk,arrk,aaarrrrgk’.  The Australian Raven emits a series of slow notes  ‘aaaark…aaaark… aaaark… aaargargh’ the finish is drawn out sounding almost strangled.

Other physical differences between these birds include tail shape, for example  the Torresian Crow has a square cut slightly broader tail while the Australian Raven has a long slender round tipped tail and the base of the adult feathers on the Torressian Crow are white while those of the Australian Raven are dark grey.

More information on the Corvid family can be found at www.birdsinbackyards.net recordings of the calls of both the Torresian Crow and the Australian Raven can be heard on this web site. An Identification Comparison Table listing the numerous differences between all 6 species of Corvids can be viewed at www.birdsqueensland.org.au.

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