Sandgrouse is the common name for Pteroclidae , a
family
Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...
of sixteen species of
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 ...
, members of the order Pterocliformes . They are traditionally placed in two
genera
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...
. The two central Asian species are classified as ''
Syrrhaptes
''Syrrhaptes'' is a genus of birds in the sandgrouse family. The genus name is from Ancient Greek
''surrhaptos'', "sewn together"; the feathered toes of birds in this genus are fused together.
There are two central Asian species.
These are lar ...
'' and the other fourteen species, from Africa and Asia, are placed in the genus ''
Pterocles
''Pterocles '' is a genus of near passerine birds in the sandgrouse family. It includes all the species in the family except for two central Asian species in '' Syrrhaptes''
These sandgrouse have small, pigeon-like heads and necks, but sturdy co ...
''. They are ground dwelling birds restricted to treeless, open country, such as plains, savannahs, and semi-deserts. They are distributed across northern, southern, and eastern Africa, Madagascar, the Middle East, and India through central Asia. The ranges of the
black-bellied sandgrouse
The black-bellied sandgrouse (''Pterocles orientalis'') is a medium large bird in the sandgrouse family.
The nominate race breeds in Iberia, northwest Africa, the Canary Islands, Turkey, Iran, Cyprus and Israel. The eastern form ''P. o. arenar ...
and the pin-tailed sandgrouse even extend into the Iberian Peninsula and France, and
Pallas's sandgrouse
Pallas's sandgrouse (''Syrrhaptes paradoxus'') is a medium to large bird in the sandgrouse family.
Naming
Marco Polo mentions a bird called ''Bargherlac'' (from Turkmen ''bağırlak'') in ''The Travels of Marco Polo'', published around 1300. ...
occasionally
breaks out in large numbers from its normal range in Asia.
Description
Sandgrouse have small, pigeon-like heads and necks and sturdy compact bodies. They range in size from in length and from in weight. The adults are
sexually dimorphic
Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...
with the males being slightly larger and more brightly colored than the females. They have eleven strong primary feathers and long pointed wings, giving them a fast and direct flight. The muscles of the wings are powerful and the birds are capable of rapid
take off and sustained flight. In some species, the central feathers in the tail are extended into long points.
The legs are short and members of the genus ''
Syrrhaptes
''Syrrhaptes'' is a genus of birds in the sandgrouse family. The genus name is from Ancient Greek
''surrhaptos'', "sewn together"; the feathered toes of birds in this genus are fused together.
There are two central Asian species.
These are lar ...
'' have feathers growing on both the legs and toes, and no hind toes, while members of the genus ''
Pterocles
''Pterocles '' is a genus of near passerine birds in the sandgrouse family. It includes all the species in the family except for two central Asian species in '' Syrrhaptes''
These sandgrouse have small, pigeon-like heads and necks, but sturdy co ...
'' have legs feathered just at the front, no feathers on the toes, and rudimentary hind toes raised off the ground.
The
plumage
Plumage ( "feather") is a layer of feathers that covers a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage differ between species and subspecies and may vary with age classes. Within species, ...
is
cryptic
Cryptic may refer to:
In science:
* Cryptic species complex, a group of species that are very difficult to distinguish from one another
* Crypsis, the ability of animals to blend in to avoid observation
* Cryptic era, earliest period of the Earth
...
, generally being in shades of sandy brown, grey and buff, and variously mottled and barred, enabling the birds to merge into the dusty landscape. There is a dense layer of under
down which helps insulate the bird from extremes of heat and cold. The feathers of the belly are specially adapted for absorbing water and retaining it, allowing adults, particularly males, to carry water to chicks that may be many miles away from watering holes.
The amount of water that can be carried in this way is 15 to 20 millilitres (0.5 to 0.7 fluid ounces).
Distribution
![Syrrhaptes paradoxus 1](https://upload.wikimedia.org/wikipedia/commons/0/0a/Syrrhaptes_paradoxus_1.JPG)
Members of the genus ''Syrrhaptes'' are found in the
steppe
In physical geography, a steppe () is an ecoregion characterized by grassland plains without trees apart from those near rivers and lakes.
Steppe biomes may include:
* the montane grasslands and shrublands biome
* the temperate grasslands, ...
s of central Asia. Their range extends from the
Caspian Sea
The Caspian Sea is the world's largest inland body of water, often described as the world's largest lake or a full-fledged sea. An endorheic basin, it lies between Europe and Asia; east of the Caucasus, west of the broad steppe of Central Asia ...
through southern
Siberia
Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a part of ...
,
Tibet
Tibet (; ''Böd''; ) is a region in East Asia, covering much of the Tibetan Plateau and spanning about . It is the traditional homeland of the Tibetan people. Also resident on the plateau are some other ethnic groups such as Monpa people, ...
, and
Mongolia
Mongolia; Mongolian script: , , ; lit. "Mongol Nation" or "State of Mongolia" () is a landlocked country in East Asia, bordered by Russia to the north and China to the south. It covers an area of , with a population of just 3.3 million, ...
to northern and central
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...
. They are normally resident, but
Pallas's sandgrouse
Pallas's sandgrouse (''Syrrhaptes paradoxus'') is a medium to large bird in the sandgrouse family.
Naming
Marco Polo mentions a bird called ''Bargherlac'' (from Turkmen ''bağırlak'') in ''The Travels of Marco Polo'', published around 1300. ...
can be locally
migratory and very occasionally is irruptive, appearing in areas well outside its normal range. This happened in 1863 and 1888, and a major irruption took place in 1908 when many birds were seen as far afield as Ireland and the United Kingdom where they bred in
Yorkshire
Yorkshire ( ; abbreviated Yorks), formally known as the County of York, is a Historic counties of England, historic county in northern England and by far the largest in the United Kingdom. Because of its large area in comparison with other Eng ...
and
Moray
Moray () gd, Moireibh or ') is one of the 32 local government council areas of Scotland. It lies in the north-east of the country, with a coastline on the Moray Firth, and borders the council areas of Aberdeenshire and Highland.
Between 1975 ...
.
[
Members of the genus ''Pterocles'' are mainly found in the drier parts of northern, eastern, and southern ]Africa
Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...
, though the range of some species extends into the Middle East
The Middle East ( ar, الشرق الأوسط, ISO 233: ) is a geopolitical region commonly encompassing Arabian Peninsula, Arabia (including the Arabian Peninsula and Bahrain), Anatolia, Asia Minor (Asian part of Turkey except Hatay Pro ...
and western Asia
Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area ...
. The Madagascar sandgrouse is restricted to Madagascar
Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...
. The black-bellied sandgrouse
The black-bellied sandgrouse (''Pterocles orientalis'') is a medium large bird in the sandgrouse family.
The nominate race breeds in Iberia, northwest Africa, the Canary Islands, Turkey, Iran, Cyprus and Israel. The eastern form ''P. o. arenar ...
and the pin-tailed sandgrouse
The pin-tailed sandgrouse (''Pterocles alchata'') is a medium large bird in the sandgrouse family. It has a small, pigeon like head and neck and a sturdy, compact body. It has long pointed wings, which are white underneath, a long tail and a fast ...
also occur in 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 ...
, Portugal
Portugal, officially the Portuguese Republic ( pt, República Portuguesa, links=yes ), is a country whose mainland is located on the Iberian Peninsula of Southwestern Europe, and whose territory also includes the Atlantic archipelagos of ...
, and southern 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 ...
. Most species are sedentary
Sedentary lifestyle is a lifestyle type, in which one is physically inactive and does little or no physical movement and or exercise. A person living a sedentary lifestyle is often sitting or lying down while engaged in an activity like soci ...
though some make local migrations, typically to lower altitudes in winter.[
]
Behaviour and ecology
Diet and feeding
Sandgrouse are principally seed eaters. Other food items eaten include green shoots and leaves, bulb
In botany, a bulb is structurally a short stem with fleshy leaves or leaf basesBell, A.D. 1997. ''Plant form: an illustrated guide to flowering plant morphology''. Oxford University Press, Oxford, U.K. that function as food storage organs duri ...
s, and berries
A berry is a small, pulpy, and often edible fruit. Typically, berries are juicy, rounded, brightly colored, sweet, sour or tart, and do not have a stone or pit, although many pips or seeds may be present. Common examples are strawberries, raspb ...
. Insect food such as ant
Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of 22 ...
s and termite
Termites are small insects that live in colonies and have distinct castes (eusocial) and feed on wood or other dead plant matter. Termites comprise the infraorder Isoptera, or alternatively the epifamily Termitoidae, within the order Blattode ...
s may also be eaten, especially during the breeding season.[ The diet of many sandgrouse is highly specialised, with the seeds of a small number of plant species being dominant. This may depend on local availability but in other cases it reflects actual selection of favoured seeds over others by the sandgrouse. Seeds of ]leguminous
A legume () is a plant in the family Fabaceae (or Leguminosae), or the fruit or seed of such a plant. When used as a dry grain, the seed is also called a pulse. Legumes are grown agriculturally, primarily for human consumption, for livestock for ...
plants are usually an important part of the diet. In agricultural
Agriculture or farming is the practice of cultivating Plant, plants and livestock. Agriculture was the key development in the rise of Sedentism, sedentary human civilization, whereby farming of Domestication, domesticated species created food ...
areas oat
The oat (''Avena sativa''), sometimes called the common oat, is a species of cereal grain grown for its seed, which is known by the same name (usually in the plural, unlike other cereals and pseudocereals). While oats are suitable for human con ...
s and other grain are readily taken. Seeds are either collected from the ground or directly from the plants.
Foraging
Foraging is searching for wild food resources. It affects an animal's Fitness (biology), fitness because it plays an important role in an animal's ability to survive and reproduce. Optimal foraging theory, Foraging theory is a branch of behaviora ...
techniques vary between species that coexist, which reduces competition; in Namibia, double-banded sandgrouse
The double-banded sandgrouse (''Pterocles bicinctus'') is a species of ground-living bird in the family Pteroclidae. It is found in arid parts of southern Africa.
Subspecies
There are three subspecies: ''P. b. ansorgei'' is found in south west A ...
feed slowly and methodically whilst Namaqua sandgrouse
The Namaqua sandgrouse (''Pterocles namaqua''), is a species of ground-dwelling bird in the sandgrouse family. It is found in arid regions of south-western Africa.
Taxonomy
The Namaqua sandgrouse was formally described in 1789 by the German na ...
feed rapidly, exploring loose soil with their beaks and flicking it away sideways. Grit is also swallowed to help grind up food in the gizzard
The gizzard, also referred to as the ventriculus, gastric mill, and gigerium, is an organ found in the digestive tract of some animals, including archosaurs (pterosaurs, crocodiles, alligators, dinosaurs, birds), earthworms, some gastropods, so ...
.[
Sandgrouse are gregarious, feeding in flocks of up to 100 birds. As a consequence of their dry diet, they need to visit water sources regularly. Drinking times vary among the species. Ten species drink at dawn, four at dusk, and two at indeterminate times.][ When drinking, water is sucked into the beak, which is then raised to let the water flow down into the crop. By repeating this procedure rapidly, enough water to last twenty four hours can be swallowed in a few seconds.][ As they travel to water holes, they ]call
Call or Calls may refer to:
Arts, entertainment, and media Games
* Call, a type of betting in poker
* Call, in the game of contract bridge, a bid, pass, double, or redouble in the bidding stage
Music and dance
* Call (band), from Lahore, Paki ...
to members of their own species and many hundreds or thousands synchronise their arrival at the drinking site despite converging from many different locations scattered over hundreds of square miles (kilometres) of territory.
They are vulnerable to attack while watering but with a large number of birds milling about, predators find it difficult to select a target bird and are likely to have been spotted before they can get close to the flock.[ The choice of a watering site is influenced by the topography of the nearby ground. The sandgrouse tend to avoid sites with cover for mammalian predators and their greatest risk is usually from predatory birds.
Sandgrouse travel tens of miles to their traditional water holes and tend to disregard temporary water sources which may appear periodically. This clearly has a survival value, because a dried up water source in an arid region could result in dehydration and death.][ The Burchell's sandgrouse in the ]Kalahari Desert
The Kalahari Desert is a large semi-arid sandy savanna in Southern Africa extending for , covering much of Botswana, and parts of Namibia and South Africa.
It is not to be confused with the Angolan, Namibian, and South African Namib coastal de ...
sometimes travels over daily to reach a water source.[ Not all species need to drink every day, and the ]Tibetan sandgrouse
The Tibetan sandgrouse (''Syrrhaptes tibetanus'') is a large bird in the sandgrouse family. The genus name ''Syrrhaptes'' is from Ancient Greek ''surrhaptos'', "sewn together" (the feathered toes of this sandgrouse are fused together) and ''tib ...
does not need to travel to drink, because of the abundance of water from melting snowfields in its habitat.[
]
Breeding
Sandgrouse are monogamous
Monogamy ( ) is a form of Dyad (sociology), dyadic Intimate relationship, relationship in which an individual has only one Significant other, partner during their lifetime. Alternately, only one partner at any one time (Monogamy#Serial monogamy, ...
. The breeding season usually coincides with a crop of seeds after the local rainy season and at this time the feeding flocks tend to break up into pairs. The nesting site is a slight depression in the ground, sometimes lined with a few pieces of dry foliage. Most typically, three cryptic eggs are laid, though occasionally there may be two or four. The intricately patterned, precocial downy young, and egg colouration (though not shape) closely resemble those of many Charadriiformes
Charadriiformes (, from ''Charadrius'', the type genus of family Charadriidae) is a diverse order of small to medium-large birds. It includes about 390 species and has members in all parts of the world. Most charadriiform birds live near water an ...
. Eggs are near elliptical.[ Incubation duties are shared; in most species, the males incubate at night while the females sit on the eggs during the day. The eggs usually hatch after 20–25 days.
The ]precocial
In biology, altricial species are those in which the young are underdeveloped at the time of birth, but with the aid of their parents mature after birth. Precocial species are those in which the young are relatively mature and mobile from the mome ...
chicks are covered with down and leave the nest as soon as the last hatchling has dried out. The parents do not provide them with food and they learn, with parental guidance, what is edible and what is not. The chicks obtain their water from the soaked downy feathers on the adults' breasts. Chicks are too small and young to thermoregulate
Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when the surrounding temperature is very different. A thermoconforming organism, by contrast, simply adopts the surrounding temperature ...
at first, and their parents shade them during the hottest part of the day, and brood them to keep warm at night. The chicks remain with their parents, as a family group, for several months.[
]
Taxonomy
The Pteroclidae was formerly included in the Galliformes
Galliformes is an order of heavy-bodied ground-feeding birds that includes turkeys, chickens, quail, and other landfowl. Gallinaceous birds, as they are called, are important in their ecosystems as seed dispersers and predators, and are often ...
due to the similarities the family shares with the true grouse. However, it was later discovered that these similarities are superficial and a result of convergent evolution
Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last com ...
. Sandgrouse were later placed near the Columbiformes
Columbidae () is a bird family consisting of doves and pigeons. It is the only family in the order Columbiformes. These are stout-bodied birds with short necks and short slender bills that in some species feature fleshy ceres. They primarily ...
largely due to their reported ability to drink by the "sucking" or "pumping" action of peristalsis
Peristalsis ( , ) is a radially symmetrical contraction and relaxation of muscles that propagate in a wave down a tube, in an anterograde direction. Peristalsis is progression of coordinated contraction of involuntary circular muscles, which ...
of the esophagus
The esophagus (American English) or oesophagus (British English; both ), non-technically known also as the food pipe or gullet, is an organ in vertebrates through which food passes, aided by peristaltic contractions, from the pharynx to the ...
, an unusual characteristic. More recently, it has been reported that they cannot suck up water in this way, and they are now treated separately in the order Pterocliformes. They have been considered near passerine
Near passerines and higher land-bird assemblage are terms of traditional, pre-cladistic taxonomy that have often been given to tree-dwelling birds or those most often believed to be related to the true passerines (order Passeriformes) owing to mor ...
birds, and are thought by some to be closer to the shorebirds (Charadriiformes
Charadriiformes (, from ''Charadrius'', the type genus of family Charadriidae) is a diverse order of small to medium-large birds. It includes about 390 species and has members in all parts of the world. Most charadriiform birds live near water an ...
).
In the DNA-study by Fain and Houde (2004) they were included in the Metaves
Metaves ("other birds") is a controversial group proposed by Fain & Houde (2004) and later rescued on the studies of Ericson ''et al.'' (2006)Ericson, P.G.P. ''et al.'' (2006Diversification of Neoaves: integration of molecular sequence data and f ...
, together with the Columbiformes. In the larger study by Hackett et al. (2008) they were once again positioned close to the Columbiformes, in Columbimorphae
Columbimorphae is a clade discovered by genome analysis that includes birds of the orders Columbiformes (pigeons and doves), Pterocliformes
Sandgrouse is the common name for Pteroclidae , a family (biology), family of sixteen species of bird ...
, but also with the Mesites.
Phylogeny
Living Pterocliformes, based on the work by John Boyd.
Species
Relations with humans
Sandgrouse have little interaction with people, primarily because most species live in arid unpopulated areas and at low densities. They are not generally sought after as game bird
Galliformes is an order of heavy-bodied ground-feeding birds that includes turkeys, chickens, quail, and other landfowl. Gallinaceous birds, as they are called, are important in their ecosystems as seed dispersers and predators, and are often ...
s as they are not especially palatable, although they have on occasion been taken in great numbers at water holes. An attempt to introduce them into Nevada
Nevada ( ; ) is a U.S. state, state in the Western United States, Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. N ...
failed but they have been introduced to Hawaii
Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only stat ...
. No species is considered to be threatened although there have been some localised range contractions, particularly in Europe. A subspecies of the chestnut-bellied sandgrouse, ''P. e. floweri'', was last seen in the Nile Valley
The Nile, , Bohairic , lg, Kiira , Nobiin: Áman Dawū is a major north-flowing river in northeastern Africa. It flows into the Mediterranean Sea. The Nile is the longest river in Africa and has historically been considered the longest rive ...
of Egypt in 1979. It is thought to be extinct, but the reasons for this are unknown.
References
External links
Sandgrouse videos
on the Internet Bird Collection
*
{{Good article
Pteroclididae
Taxa named by Charles Lucien Bonaparte