Flamingos are gregarious wading birds in the genus Phoenicopterus and family Phoenicopteridae. They are found in both the Western and Eastern Hemispheres, but are more numerous in the latter. There are four species in the Americas while two exist in the Old World.
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Andean Flamingos in the Laguna Colorada, Bolivia.The prehistory of
the Phoenicopteriformes is far better researched than their
systematic affinities (see below). An extinct family of peculiar
"swimming flamingos", the Palaelodidae, was initially believed to be
the ancestors of the Phoenicopteridae. This is nowadays rejected, as
the fossil genus Elornis, apparently a true albeit primitive
flamingo, is known from the Late Eocene, before any palaelodid
flamingos have been recorded. A considerable number of little-known
birds from the Late Cretaceous onwards are sometimes considered to
be flamingo ancestors. These include the genera Torotix,
Parascaniornis, Scaniornis, Gallornis, Agnopterus, Tiliornis,
Juncitarsus and Kashinia; the latter two are probably
proto-flamingos, while the relationships of the others are not clear
at present. There exists a fairly comprehensive fossil record of the
genus Phoenicopterus. The systematics of prehistoric
Phoenicopteriformes known only from fossils is as follows:
The identity of the closest relatives of the flamingos is a rather
contentious issue. Traditionally, the long-legged Ciconiiformes,
probably a paraphyletic assemblage, have been considered the
flamingos' closest relatives and the family was included in the
order. Usually the spoonbills and ibises of the Threskiornithidae
were considered their closest relatives within this order.
Nevertheless, relationships to the Anseriformes (waterfowl) were
considered as well (Sibley et al. 1969), especially as flamingos and
waterfowl are parasitized by feather lice of the genus Anaticola
(Johnson et al. 2006).
To reflect the uncertainty about this matter, flamingos began to be
placed in their own order later on. Other scientists proposed
flamingos as waders most closely related to the stilts and avocets,
Recurvirostridae. The peculiar presbyornithids were used to argue
for a close relationship between flamingos, waterfowl, and waders (Feduccia
1976), but they are now known to be unequivocal waterfowl with a
peculiarly derived morphology paralleling waders and flamingos.
In recent years, molecular and anatomical studies have yielded
confusing results: Sibley & Monroe placed flamingos within their
expanded (and certainly paraphyletic, as is now known) Ciconiiformes.
On the other hand, since long it has been the grebes (Podicipedidae),
rather than Ciconiiformes, ducks, or stilts, that were time and
again indicated as the closest relatives of flamingos, and there is
currently renewed interest in this hypothesis.
In a 2004 study comparing DNA sequences of intron 7 of the
β-fibrinogen gene (FGB-int7), the Neognathae (all living birds
except the ratites and tinamous) excluding waterfowl and Galliformes
were shown to be divided into two subgroups of uneven size. The
first and smaller one, Metaves, contains flamingos and grebes,
alongside the hoatzin, pigeons, sandgrouse, the Caprimulgiformes,
the Apodiformes, tropicbirds, mesites, sunbittern and kagu.
Interestingly, most of these groups have traditionally been
difficult to place on the family tree of birds. According to this
study, all other birds belong to the second subgroup of Neoaves, the
Coronaves (Fain & Houde 2004).
But their molecular data was insufficient to resolve inter-Metaves
relationships to satisfaction; the flamingo FGB-int7 sequence is
apparently most similar to that of some species of nighthawks,
strongly suggesting a case of convergent evolution on the molecular
level. The conclusions that one can draw from this study are
twofold: first, that flamingos are Metaves (if that group is not
based on molecular convergence, for which there are some
indications), and second, that FBG-int7 is unsuitable to determine
their relationships beyond that. It is interesting to note, however,
that among all the groups which have been proposed as sister taxa of
the flamingos, only the grebes are Metaves.
In conclusion, the relationships of the flamingos still cannot be
resolved with any certainty, but presently a close relationship with
grebes appears somewhat more likely than other proposals. For this
clade, the taxon Mirandornithes ("miraculous birds" due to their
extreme convergence and apomorphies) has been proposed. In summary,
all this confusion serves to show that all lines of "evidence" -
molecular, morphological, ecological and parasitological - are
liable to yield erroneous "proof" and that no method can be
considered generally superior. Any future attempt to finally resolve
the flamingos' relationships, therefore, would have to employ total
evidence to support it and carefully weigh the data against
alternative proposals.
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Flamingos filter-feed on brine shrimp. Their oddly-shaped beaks
are specially adapted to separate mud and silt from the food
they consume, and are uniquely used upside-down. The filtering
of food items is assisted by hairy structures called lamellae
which line the mandibles, and the large rough-surfaced tongue.
The flamingos characterisic pink colouring is caused by the Beta
carotene in their diet. The source of this varies by species,
but shrimp and blue-green algae are common sources; zoo-fed
flamingoes may be given food with the additive canthaxanthin,
which is often also given to farmed salmon.
Flamingos frequently stand on one leg. The reason for this
behavior is not fully known. One common theory is that tucking
one leg beneath the body may conserve body heat, but this has
not been proven. It is often suggested that this is done in part
to keep the legs from getting wet, and in addition to conserving
energy. In addition to standing in the water, flamingos may
stamp their webbed feet in the mud to stir up food from the
bottom.
Young flamingos hatch with grey plumage, but the feathers of an
adult range from light pink to bright red due to the bacteria in
the water they inhabit and the pigments obtained from their food
supply. A flamingo that is well-fed and healthy is vibrantly
colored bright pink and is more desirable as a mate. A white or
pale flamingo, however, is usually unhealthy or suffering from a
lack of food. Notable exceptions are the flamingos in captivity,
many of which turn a pale pink as they are not fed foods
containing sufficient amounts of carotene. This is changing as
more zoos begin to add shrimp and other supplements to the diets
of their flamingos. In summary, flamingos obtain their color
from a shrimp-rich diet.
Flamingos produce a "milk" like pigeon milk due to the action of
a hormone called prolactin (see Columbidae). It contains more
fat and less protein than the latter does, and it is produced in
glands lining the whole of the upper digestive tract, not just
the crop. Both parents nurse their chick, and young flamingos
feed on this milk, which also contains red and white blood
cells, for about two months until their bills are developed
enough to filter feed.
Scientists have discovered that birds are dying by the thousand
along the Rift Valley lakes of Kenya and Tanzania. However, they
are baffled about the reason. Possible causes include avian
cholera, botulism, metal pollution, pesticides or poisonous
bacteria, say researchers. Also, fears for the future of the
Lesser Flamingo — Phoeniconaias minor — have also been raised by
plans to pipe water from one of their key breeding areas, the
shores of Lake Natron. The lakes are crucial to the birds'
breeding success because the flamingos feed off the blooms of
cyanobacteria that thrive there.
Most scientific attention has focused on the environmental
changes to the lakes. Water levels have lowered and
concentrations of salt in the water have increased. This
increases the risk of toxic bacteria growing there.

This Flamingo Page is Copyright The Animal Web Guide © 2004 - 2009 Chuck Ayoub