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The small
bird
Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
''Geronticus'' belongs to the
ibis
The ibises () (collective plural ibis; classical plurals ibides and ibes) are a group of long-legged wading birds in the family Threskiornithidae, that inhabit wetlands, forests and plains. "Ibis" derives from the Latin and Ancient Greek word f ...
subfamily
In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoologi ...
(Threskiornithinae). Its name is derived from the
Greek
Greek may refer to:
Greece
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group.
*Greek language, a branch of the Indo-European language family.
**Proto-Greek language, the assumed last common ancestor ...
''gérontos'' (γέρωντος, "old man") in reference to the bald head of these dark-plumaged birds; in
English
English usually refers to:
* English language
* English people
English may also refer to:
Peoples, culture, and language
* ''English'', an adjective for something of, from, or related to England
** English national ide ...
they are called bald ibises.
The genus was erected by the German naturalist
Johann Georg Wagler
Johann Georg Wagler (28 March 1800 – 23 August 1832) was a German herpetologist and ornithologist.
Wagler was assistant to Johann Baptist von Spix, and gave lectures in zoology at the Ludwig Maximilian University of Munich after it was moved ...
in 1832. The
type species
In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...
was subsequently designated as the
southern bald ibis
The southern bald ibis (''Geronticus calvus'') is a large bird found in open grassland or semi-desert in the mountains of southern Africa. Taxonomically, it is most closely related to its counterpart in the northern regions of Africa, the waldra ...
(''Geronticus calvus'').
Species
Like most ibises, they are gregarious long-legged
wading bird
245px, A flock of Dunlins and Red knots">Red_knot.html" ;"title="Dunlins and Red knot">Dunlins and Red knots
Waders or shorebirds are birds of the order Charadriiformes commonly found wikt:wade#Etymology 1, wading along shorelines and mudflat ...
s with long down-curved
bills; they form one subfamily of the
Threskiornithidae
The family Threskiornithidae includes 36 species of large wading birds. The family has been traditionally classified into two subfamilies, the ibises and the spoonbills; however recent genetic studies have cast doubt on this arrangement, and ha ...
, the other subfamily being the
spoonbill
Spoonbills are a genus, ''Platalea'', of large, long-legged wading birds. The spoonbills have a global distribution, being found on every continent except Antarctica. The genus name ''Platalea'' derives from Ancient Greek and means "broad", refe ...
s. The two ''Geronticus'' species differ from other ibises in that they have unfeathered faces and heads, breed on cliffs rather than in trees, and prefer
arid
A region is arid when it severely lacks available water, to the extent of hindering or preventing the growth and development of plant and animal life. Regions with arid climates tend to lack vegetation and are called xeric or desertic. Most ar ...
habitats to the
wetlands
A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (anoxic) processes prevailing, especially in the soils. The ...
used by their relatives. Their food contains fewer
aquatic animals
An aquatic animal is any animal, whether invertebrate or vertebrate, that lives in water for most or all of its lifetime. Many insects such as mosquitoes, mayflies, dragonflies and caddisflies have aquatic larvae, with winged adults. Aquatic anim ...
and more
terrestrial
Terrestrial refers to things related to land or the planet Earth.
Terrestrial may also refer to:
* Terrestrial animal, an animal that lives on land opposed to living in water, or sometimes an animal that lives on or near the ground, as opposed to ...
ones; they are known to gather together and feed on
locust
Locusts (derived from the Vulgar Latin ''locusta'', meaning grasshopper) are various species of short-horned grasshoppers in the family Acrididae that have a swarming phase. These insects are usually solitary, but under certain circumstanc ...
swarms, killing many of these notorious
pests. This has also contributed to their decline however, as they were much affected by indiscriminate
pesticide
Pesticides are substances that are meant to control pests. This includes herbicide, insecticide, nematicide, molluscicide, piscicide, avicide, rodenticide, bactericide, insect repellent, animal repellent, microbicide, fungicide, and lampri ...
spraying in the mid-to-late 20th century, leading to their disappearance from many regions.
Fossil record
''Geronticus perplexus'' is by far the oldest
fossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...
assigned to the present genus. It is known only from a piece of
distal
Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position pro ...
right
humerus
The humerus (; ) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius and ulna, and consists of three sections. The humeral upper extremity consists of a roun ...
, found at
Sansan,
France
France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...
, in
Middle Miocene
The Middle Miocene is a sub-epoch of the Miocene Epoch made up of two stages: the Langhian and Serravallian stages. The Middle Miocene is preceded by the Early Miocene.
The sub-epoch lasted from 15.97 ± 0.05 Ma to 11.608 ± 0.005 Ma (million y ...
rocks of the
Serravallian
The Serravallian is, in the geologic timescale, an List of time periods, age or a stage (stratigraphy), stage in the middle Miocene epoch (geology), Epoch/series (stratigraphy), Series, which spans the time between 13.82 annum, Ma and 11.63 Ma (m ...
faunal stage
MN 6 (about 12-14 million years ago). It was initially considered to be a
heron
The herons are long-legged, long-necked, freshwater and coastal birds in the family Ardeidae, with 72 recognised species, some of which are referred to as egrets or bitterns rather than herons. Members of the genera ''Botaurus'' and ''Ixobrychus ...
and placed in the genera ''
Ardea'' and ''
Proardea
''Proardea'' is an extinct genus of heron, containing two species, ''Proardea amissa'' ("lost proto-heron") and ''Proardea? deschutteri'' from the Borgloon Formation of Belgium. It stood about 70 cm (2 ft 4 in) tall and was very si ...
''. More
plesiomorph
In phylogenetics, a plesiomorphy ("near form") and symplesiomorphy are synonyms for an ancestral character shared by all members of a clade, which does not distinguish the clade from other clades.
Plesiomorphy, symplesiomorphy, apomorphy, and ...
ic than the living species, it seems to represent an ancient member of the ''Geronticus'' lineage, in line with the theory that most living ibis genera seem to have
evolved before 15 million years ago (mya).
''Geronticus apelex'' is apparently the direct ancestor of the southern bald ibis. Its remains were found in
Early Pliocene
Early may refer to:
History
* The beginning or oldest part of a defined historical period, as opposed to middle or late periods, e.g.:
** Early Christianity
** Early modern Europe
Places in the United States
* Early, Iowa
* Early, Texas
* Early ...
deposits near
Langebaanweg
Langebaanweg is a town on the southwest coast of South Africa, in Western Cape Province.
It is the location of the air force base AFB Langebaanweg.
Langebaanweg has been an important mining center, with its mai minerals consisting of phosphorite ...
,
South Africa
South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...
, which date back about five million years.
What may be an ancestral
Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...
an form, ''Geronticus balcanicus'', was found in a
Late Pliocene
Late may refer to:
* LATE, an acronym which could stand for:
** Limbic-predominant age-related TDP-43 encephalopathy, a proposed form of dementia
** Local-authority trading enterprise, a New Zealand business law
** Local average treatment effect, ...
deposit near
Slivnitsa,
Bulgaria
Bulgaria (; bg, България, Bǎlgariya), officially the Republic of Bulgaria,, ) is a country in Southeast Europe. It is situated on the eastern flank of the Balkans, and is bordered by Romania to the north, Serbia and North Macedon ...
. It is hitherto only known from one left and one right
carpometacarpus
The carpometacarpus is a bone found in the hands of birds. It results from the fusion of the carpal and metacarpal bone, and is essentially a single fused bone between the wrist and the knuckles. It is a smallish bone in most birds, generally flat ...
piece (
NMNHS
The National Museum of Natural History ( bg, Национален природонаучен музей, ''Natsionalen prirodonauchen muzey''; abbreviated НПМ, NMNHS) of Bulgaria is a natural history museum located in Sofia, the capital o ...
14 and NMNHS 453, respectively) which are almost identical to those of living bald ibises. Contemporaneous with these during the early
MN18 faunal stage
In chronostratigraphy, a stage is a succession of rock strata laid down in a single age on the geologic timescale, which usually represents millions of years of deposition. A given stage of rock and the corresponding age of time will by convent ...
– about two mya – birds entirely indistinguishable from the modern northern bald ibis inhabited at least
Spain
, image_flag = Bandera de España.svg
, image_coat = Escudo de España (mazonado).svg
, national_motto = ''Plus ultra'' (Latin)(English: "Further Beyond")
, national_anthem = (English: "Royal March")
, i ...
, if not the whole western Mediterranean region already. Thus, the extinct species may be the immediate ancestor of ''G. eremita'', which would have originated at the western extent of its range. Some authors even include the Bulgarian population in ''G. eremita'', but most are more cautious. ''G. balcanicus'' may also represent a lineage related but not ancestral to the northern bald ibis, which inhabited the inland regions northeastwards of the European
Alpide
The Alpide belt or Alpine-Himalayan orogenic belt,K.M. Storetvedt, K. M., ''The Tethys Sea and the Alpine-Himalayan orogenic belt; mega-elements in a new global tectonic system,'' Physics of the Earth and Planetary Interiors, Volume 62, Issues 1 ...
s and – like the immediate ancestor of ''G. eremita'' in this scenario – was isolated from the ancestors of ''G. calvus'' when
gene flow
In population genetics, gene flow (also known as gene migration or geneflow and allele flow) is the transfer of genetic material from one population to another. If the rate of gene flow is high enough, then two populations will have equivalent a ...
across
tropical
The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in
the Southern Hemisphere at S. The tropics are also referred to ...
Africa ceased.
[del Hoyo ''et al.'' (1992), Boev (1998, 2002), Mlíkovský (2002)]
Footnotes
References
* Boev, Zlatozar (1998): Presence of Bald Ibises (''Geronticus'' Wagler, 1832) (Threskiornithidae - Aves) in the Late Pliocene of Bulgaria. ''Geologica Balcanica'' 28 (1–2): 45–52.
* Boev, Zlatozar (2002):Additional Material of ''Geronticus balcanicus'' Boev, 1998, and Precision of the Age of the Type Locality. ''Acta Zoologica Bulgarica'' 52 (2): 53–58
nglish with Bulgarian abstractbr>
full text* Brookes, Ian (ed.) (2006): ''
The Chambers Dictionary
The ''Chambers Dictionary'' (''TCD'') was first published by William and Robert Chambers as ''Chambers's English Dictionary'' in 1872. It was an expanded version of ''Chambers's Etymological Dictionary'' of 1867, compiled by James Donald. A sec ...
'' (9th ed.). Chambers, Edinburgh.
* , del Hoyo, Josep; Elliott, Andrew & Sargatal, Jordi (eds.) (1992): ''
Handbook of Birds of the World
The ''Handbook of the Birds of the World'' (HBW) is a multi-volume series produced by the Spanish publishing house Lynx Edicions in partnership with BirdLife International. It is the first handbook to cover every known living species of bird. Th ...
'' (Vol. 1: Ostrich to Ducks). Lynx Edicions, Barcelona.
* Mlíkovský, Jirí (2002): ''Cenozoic Birds of the World'' (Part 1: Europe). Ninox Press, Prague.
PDF fulltext!-- This should be treated with extreme caution as regards merging of species. Splits are usually good though. See also critical review in Auk121:623-627 here http://www.findarticles.com/p/articles/mi_qa3793/is_200404/ai_n9396879 -->
* Sinclair, Ian; Hockey, Phil & Tarboton, Warwick R. (2002): ''SASOL Birds of Southern Africa''. Struik, Cape Town
* Snow, David W. & Perrins, Christopher M. (eds.) (1998): ''The Birds of the Western Palearctic'' (concise ed.). Oxford University Press.
External links
Geronticus, Systema Naturae 2000Navigate: Taxon Index, Genus Level, G
Bald Ibis by Adam Riley Focusing on Wildlife
{{Taxonbar, from=Q913200
Bird genera
Serravallian first appearances
Extant Miocene first appearances