White-breasted cormorant, Phalacrocorax lucidus (synonym, Phalacrocorax carbo lucidus; protonym, Halieus lucidus), Lichtenstein, MHK, 1823, also known as the white-necked cormorant or as the (African) great cormorant, photographed at Hora Lake Kilole (Lake Chilotes), Debre Zeyt, Ethiopia (Africa).
Image: Dan Logen, 26 January 2011 (with permission) [velociraptorize].
Nikon D300s, 600 mm lens, f/4, 1/5000 sec, ISO 640
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Question: This African mystery bird's name indicates it once was thought to be part of a very different (and unrelated) group of birds. What group of birds might that be? Can you identify this bird's taxonomic family and species?
Response: This is an African white-breasted cormorant, Phalacrocorax lucidus, a species that was only recently split from the great black cormorant, Phalacrocorax carbo. However, some authorities (Sibley & Monroe [Amazon UK; Amazon US] and Sinclair, Hockey & Tarboton [Amazon UK; Amazon US]) still consider this to be a subspecies or allospecies of the great black cormorant.
The name, "cormorant" is derived from the Latin, corvus marinus, for "sea raven" or "sea crow". Surprisingly (to me, anyway), cormorants were thought to be related to corvids until at least the 16th century. For example, French explorer André Thévet wrote in in his book, "About birds of Ascension Island", in 1558 that "...the beak [is] similar to that of a cormorant or other corvid." (French; original text here).
To my eyes (and to my calipers), none of the cormorants look anything at all like any passerine species, including the corvids. To start, a cormorant's beak is not at all shaped like a corvid's beak. Further, a quick dissection would easily rule out any relationship between these two taxa: corvids are passerines and they possess a passerine's characteristic syrinx at the base of the trachea, whereas a cormorant's syrinx looks distinctly different. Birds produce vocal sounds using the syrinx, but only songbirds control their sounds using two separate sets of muscles and membranes -- which means they can sing two notes at the same time. Not so for cormorants! Embedded below is a 2 minute radio programme that compares a cormorant syrinx to that of a passerine, thanks to my friends at BirdNote Radio:
Visit BirdNote's "How Birds Produce Sound" programme page [audio podcast link].
Cormorants comprise the taxonomic family, Phalacrocoracidae, which is placed in the far-removed-from-passeriformes taxonomic order, Pelecaniformes -- or in Ciconiiformes, if you adhere to Sibley & Ahlquist's taxonomy [Amazon UK; Amazon US]. Currently, we're not sure about the precise relationships between cormorants and other birds, although we are fairly certain they are closest to the darters and to the gannets and boobies (Sulidae) and are probably closer to the pelicans and maybe even to the penguins than to any other avian taxa.
Even though cormorants are considered to be "seabirds" by many (perhaps because of their "sea crow" name), they are more correctly known as waterbirds because they do not often venture out to sea: instead, they live along the shorelines of marine, brackish and freshwater.
The white-breasted cormorant's sister taxon, the great black cormorant is a widely-ranging species found throughout much of the Old World and along the Atlantic coast of North America. The great black cormorants vary widely in appearance and size throughout their extensive range, leading some authorities to recognize it as a superspecies group or as a species-complex. In fact, even at the DNA level (which is poorly sampled for this group), it is difficult to adequately distinguish the species within this family beyond superspecies or species-complexes. And of course, their propensity to hybridise adds to the confusion.
That said, the white-breasted cormorant can be distinguished from the great black cormorant, its sister species and former conspecific, by its white underparts that are sharply separated from its black upperparts.
You are invited to review all of the daily mystery birds by going to their dedicated graphic index page.
If you have bird images, video or mp3 files that you'd like to share with a large and (mostly) appreciative international audience here at The Guardian, feel free to contact me to learn more.
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