Branta

Branta; Temporal range: ; Late Miocene-Holocene
	A Canada goose (Branta canadensis) swimming at Smythe Park, Toronto, Ontario, Canada
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Anseriformes
Family:	Anatidae
Subfamily:	Anserinae
Genus:	Branta; Scopoli, 1769
Species
	Branta bernicla; Branta canadensis; Branta hutchinsii; Branta leucopsis; Branta ruficollis; Branta sandvicensis; and see text
Synonyms
	Nesochen Salvadori, 1895

The black geese of the genus Branta are waterfowl belonging to the true geese and swans subfamily Anserinae. They occur in the northern coastal regions of the Palearctic and all over North America, migrating to more southernly coasts in winter, and as resident birds in the Hawaiian Islands. Alone in the Southern Hemisphere, a self-sustaining feral population derived from introduced Canada geese is also found in New Zealand.

The scientific name Branta is a Latinised form of Old Norse Brandgás, "burnt (black) goose".[1] The black geese derive their vernacular name for the prominent areas of black coloration found in all species. They can be distinguished from all other true geese by their legs and feet, which are black or very dark grey. Furthermore, they have black bills and large areas of black on the head and neck, with white (ochre in one species) markings that can be used to tell apart most species.[note 1] As with most geese, their undertail and uppertail coverts are white. They are also on average smaller than other geese, though some very large taxa are known, which rival the swan goose and the black-necked swan in size.

The Eurasian species of black geese have a more coastal distribution compared to the grey geese which share the same general area of occurrence, not being found far inland even in winter (except for occasional stray birds or individuals escaped from captivity). This does not hold true for the American and Pacific species, in whose ranges grey geese are for the most part absent.

Systematics

Phylogeny

Based on the Taxonomy in Flux from John Boyd's website.[2]

(Branta)

B. bernicla (Linnaeus 1758) (Brant goose)

(Leucopareia)

B. ruficollis (Pallas 1769) (Red-breasted goose)

(Leucoblepharon)

B. sandvicensis (Vigors 1834) (Nene)

B. canadensis (Linnaeus 1758) (Canada goose)

	B. leucopsis (Bechstein 1803) (Barnacle goose)

	B. hutchinsii (Richardson 1832) (Cackling goose)

Living species and taxonomy

6–8 living species of black geese are known. In addition, two species have been described from subfossil remains found in the Hawaiian Islands, where they became extinct in prehistoric times.

The species are:

Scientific name	Common Name	Distribution
Branta bernicla – three subspecies	Brant, or brent goose	High-Arctic tundra. Circumpolar; several distinct breeding populations, which winter in particular areas (some of which overlap) along northern temperate-zone Atlantic and Pacific coastlines.
Branta leucopsis	Barnacle goose	Arctic islands of the Northeast Atlantic
Branta canadensis	Canada goose	Temperate regions of North America
Branta hutchinsii – formerly included in B. canadensis	Cackling goose	North America, northern Canada and Alaska
Branta ruficollis	Red-breasted goose	Arctic Siberia, mainly on the Taymyr Peninsula, with smaller populations in the Gydan and Yamal peninsulas, northwestern shores of the Black Sea in Bulgaria, Romania and Ukraine
Branta sandvicensis	Nene, nēnē, or Hawaiian goose	Hawaiian Islands

†Nēnē-nui or woods-walking goose, Branta hylobadistes (prehistoric)

Similar but hitherto undescribed remains are known from on Kauaʻi and Oʻahu.

†Giant Hawaiʻi goose, Branta rhuax (prehistoric), formerly Geochen rhuax

The relationships of the enigmatic Geochen rhuax, formerly known only from parts of a single bird's skeleton damaged due to apparently dying in a lava flow, were long unresolved. After reexamination of the subfossil material and comparisons with other subfossil bones from the island of Hawaiʻi assigned to the genus Branta, it was redescribed as Branta rhuax in 2013.[3] While a presumed relation between B. rhuax and the shelducks, proposed by Lester Short in 1970,[4] has thus been refuted, bones of a shelduck-like bird have been found more recently on Kaua‘i. Whether this latter anatid was indeed a shelduck is presently undetermined.

Similarly, two bones found on Oʻahu indicate the erstwhile present of a gigantic waterfowl on this island. Its relationships relative to this genus and the moa-nalos, enormous goose-like dabbling ducks, are completely undeterminable at present.

Early fossil record

Several fossil species of Branta have been described. Since the true geese are hardly distinguishable by anatomical features, the allocation of these to this genus is somewhat uncertain. A number of supposed prehistoric grey geese have been described from North America, partially from the same sites as species assigned to Branta. Whether these are correctly assigned – meaning that the genus Anser was once much more widespread than today and that it coexisted with Branta in freshwater habitat which it today does only most rarely – is not clear. Especially in the case of B. dickeyi and B. howardae, doubts have been expressed about its correct generic assignment.

Branta woolfendeni (Big Sandy Late Miocene of Wickieup, USA)
Branta thessaliensis (Late Miocene of Perivolaki, Greece)
Branta dickeyi (Late Pliocene – Late Pleistocene of W USA)[4][5][6][7]
Branta esmeralda (Esmeralda Early Pliocene)[6][7][8]
Branta howardae (Ricardo Early Pliocene)[7][8][9][10]
Branta propinqua (Middle Pleistocene of Fossil Lake, USA)[4][7]
Branta hypsibata (Pleistocene of Fossil Lake, USA)[4][6][7]

The former "Branta" minuscula is now placed with the prehistoric American shelducks, Anabernicula.[7] On the other hand, a goose fossil from the Early-Middle Pleistocene of El Salvador is highly similar to Anser and given its age and biogeography it is likely to belong to that genus or Branta.[11]

Footnotes

The nēnē, which is aberrant in many respects, has no white on the head or neck and fairly little black, being quite similar to the swan goose in the color pattern of these areas, and was thus formerly assigned to the monotypic genus Nesochen. The swan goose, a grey goose, also has a black bill, but its reddish-orange legs indicate its actual relationships.

References

Jobling, James A (2010). The Helm Dictionary of Scientific Bird Names. London: Christopher Helm. p. 77. ISBN 978-1-4081-2501-4.
Taxonomy in Flux Boyd, John (2007). "Anserini" (PDF). Retrieved 30 August 2016.
Olson, Storrs L. (2013). "Hawaii's first fossil bird: history, geological age, and taxonomic status of the extinct goose Geochen rhuax Wetmore (Aves: Anatidae)". Proceedings of the Biological Society of Washington. Washington: Biological Society of Washington. 126 (2): 161–168. doi:10.2988/0006-324x-126.2.161. Retrieved 13 July 2013.
Short, Lester L. (1970). "A new anseriform genus and species from the Nebraska Pliocene" (PDF). Auk. 87 (3): 537–543. doi:10.2307/4083796.
Miller, Loye (1924). "Branta dickeyi from the McKittrick Pleistocene" (PDF). The Condor. 26 (5): 178–180. doi:10.2307/1363171.
Miller, Loye (1944). "Some Pliocene Birds from Oregon and Idaho" (PDF). The Condor. 46 (1): 25–32. doi:10.2307/1364248.
Short, Lester L. (1969). "A new genus and species of gooselike swan from the Pliocene of Nebraska". American Museum Novitates (2369). hdl:2246/2579.
Miller, Alden H.; Ashley, James F. (1934). "Goose Footprints on a Pliocene Mud-flat" (PDF). The Condor. 36 (4): 178–179. doi:10.2307/1363416.
Howard, Hildegarde (1931). "Pliocene Bird Remains from Santa Barbara, California" (PDF). The Condor. 33 (1): 30–31. doi:10.2307/1363932.
Miller, Loye (1931). "Bird Remains from the Kern River Pliocene of California" (PDF). The Condor. 33 (2): 70–72. doi:10.2307/1363312.
Cisneros, Juan Carlos (2005). "New Pleistocene vertebrate fauna from El Salvador" (PDF). Revista Brasileira de Paleontologia (in English and Portuguese). 8 (3): 239–255. doi:10.4072/rbp.2005.3.09.