The long-tailed widowbird (''Euplectes progne''), also known as the "sakabula", is a species of bird in the family

Ploceidae Ploceidae is a family of small passerine birds, many of which are called weavers, weaverbirds, weaver finches and bishops. These names come from the nests of intricately woven vegetation created by birds in this family. In most recent classifica ...

.Mackworth-Praed, C.W., and C.H. Grant. (1960). ''Birds of Eastern and North Eastern Africa''. Longmans, Green and Co LTD.; London The species are found in

Angola , national_anthem = "Angola Avante"() , image_map = , map_caption = , capital = Luanda , religion = , religion_year = 2020 , religion_ref = , coordina ...

Botswana Botswana (, ), officially the Republic of Botswana ( tn, Lefatshe la Botswana, label= Setswana, ), is a landlocked country in Southern Africa. Botswana is topographically flat, with approximately 70 percent of its territory being the Kal ...

, the DRCongo,

Kenya ) , national_anthem = " Ee Mungu Nguvu Yetu"() , image_map = , map_caption = , image_map2 = , capital = Nairobi , coordinates = , largest_city = Nairobi , ...

Lesotho Lesotho ( ), officially the Kingdom of Lesotho, is a country landlocked as an enclave in South Africa. It is situated in the Maloti Mountains and contains the highest mountains in Southern Africa. It has an area of over and has a populatio ...

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 count ...

Eswatini Eswatini ( ; ss, eSwatini ), officially the Kingdom of Eswatini and formerly named Swaziland ( ; officially renamed in 2018), is a landlocked country in Southern Africa. It is bordered by Mozambique to its northeast and South Africa to its ...

, and

Zambia Zambia (), officially the Republic of Zambia, is a landlocked country at the crossroads of Central, Southern and East Africa, although it is typically referred to as being in Southern Africa at its most central point. Its neighbours are ...

.Hall, B. P. and R. E. Moreau. (1970). An atlas of speciation in African passerine birds. British Museum of Natural History, London. The long-tailed widowbird is a medium-sized bird and one of the most common in the territories it inhabits.Andersson, M. (1982). "Female choice selects for extreme tail length in a widowbird." ''Nature'', 299: 818–820. Adult breeding males are almost entirely black with orange and white shoulders (epaulets), long, wide tails, and a bluish white bill. Females are rather inconspicuous, their feathers streaked tawny and black with pale patches on the chest, breast and back, narrow tail feathers, and horn-colored bills. When flying, male long-tailed widowbirds are readily visible due to their extremely long tails. Between six and eight of their twelve tail feathers are approximately half a metre (approximately 20 inches) long. The tail during flight display is expanded vertically into a deep, long keel below the male as he flies with slow wingbeats 0.5 to 2 metres (20 to 78 inches) above his territory. Because of the seemingly large cost to such male ornaments, the long-tailed widowbird has been the subject of extensive research into the function and evolution of sexually selected traits. This research has demonstrated the existence of female choice in sexual selection and indicates the trade-offs between sexual appeal and physical constraints with regard to the evolution of sexual ornaments.

Taxonomy

The long-tailed widowbird was described by the French polymath

Georges-Louis Leclerc, Comte de Buffon Georges-Louis Leclerc, Comte de Buffon (; 7 September 1707 – 16 April 1788) was a French naturalist, mathematician, cosmologist, and encyclopédiste. His works influenced the next two generations of naturalists, including two prominent F ...

in 1779 in his '' Histoire Naturelle des Oiseaux'' from a bird collected in the

Cape of Good Hope The Cape of Good Hope ( af, Kaap die Goeie Hoop ) ;''Kaap'' in isolation: pt, Cabo da Boa Esperança is a rocky headland on the Atlantic coast of the Cape Peninsula in South Africa. A common misconception is that the Cape of Good Hope is ...

region of South Africa. The bird was also illustrated in a hand-coloured plate engraved by

François-Nicolas Martinet François-Nicolas Martinet (1731 - 1800) was a French engineer, engraver and naturalist. Martinet engraved the plates for numerous works on natural history, especially ornithology. Notable in particular are those for ''l'Ornithologia, sive Synop ...

in the ''Planches Enluminées D'Histoire Naturelle'' which was produced under the supervision of

Edme-Louis Daubenton Edme-Louis Daubenton (12 August 1730 – 12 December 1785) was a French naturalist. Daubenton was the cousin of another French naturalist, Louis Jean-Marie Daubenton. Georges-Louis Leclerc, the Comte de Buffon engaged Edme-Louis Daubenton to su ...

to accompany Buffon's text. Neither the plate caption nor Buffon's description included a scientific name but in 1783 the Dutch naturalist

Pieter Boddaert Pieter Boddaert (1730 – 6 May 1795) was a Dutch physician and naturalist. Early life, family and education Boddaert was the son of a Middelburg jurist and poet by the same name (1694–1760). The younger Pieter obtained his M.D. at the Univers ...

coined the

binomial name In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

''Emberiza progne'' in his catalogue of the ''Planches Enluminées''. The long-tailed widowbird is now one of 17 species placed in the

genus 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 n ...

Euplectes ''Euplectes'' is a genus of passerine bird in the weaver family, Ploceidae. It contains the bishops and widowbirds. They are all native to Africa south of the Sahara. It is believed that all birds in the genus are probably polygynous. The ge ...

'' that was introduced by the English naturalist

William John Swainson William John Swainson FLS, FRS (8 October 1789 – 6 December 1855), was an English ornithologist, malacologist, conchologist, entomologist and artist. Life Swainson was born in Dover Place, St Mary Newington, London, the eldest son of ...

in 1829. The genus name combines the

Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic p ...

''eu'' "fine" or "good" and the

New Latin New Latin (also called Neo-Latin or Modern Latin) is the revival of Literary Latin used in original, scholarly, and scientific works since about 1500. Modern scholarly and technical nomenclature, such as in zoological and botanical taxonomy ...

''plectes'' "weaver". The specific ''progne'' is Latin for a "swallow. Three subspecies are recognised: * ''E. p. delamerei'' ( Shelley, 1903) – central Kenya * ''E. p. delacouri'' Wolters, 1953 – Angola, south DR Congo and Zambia * ''E. p. progne'' ( Boddaert, 1783) – southeast Botswana to east South Africa The long-tailed widowbird has three geographically differentiated subspecies. These include ''delamerei'', found in the highlands of Kenya, ''delacouri'', found in the Congo, Angola and Zambia, and ''progne'', found in Botswana, South Africa, Eswatini and Lesotho. Some researchers have suggested the existence of long-tailed widowbird superspecies based on similarity in male nuptial plumage such as tail length, but this is the topic of some debate.

Description

Long-tailed widowbirds exhibit distinct

sexual dimorphism 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 an ...

. Males and females exhibit differences in behavior and morphological traits. Adult males are entirely black, including under their wing-coverts. Males' wing shoulders are orange red and their wing-coverts white. Their bills are bluish white. Males are known for their distinctly long tails, which contain twelve tail feathers. Of these twelve tail feathers, between six and eight are approximately half a metre (approximately 20 inches) long. Males have wingspans of approximately 127 to 147 mm (approximately 5 to 5.8 inches). Females have a rather subdued coloration. The upper portion of the female's body is streaked with buff or tawny and black. Female chests, breasts and flanks are slightly paler than their above coloring. The area under the wing-coverts is black and the females' tail feathers are narrow and pointed. Finally, their bills are horn-coloured. Non-breeding males are slightly larger than females, though they demonstrate a remarkably similar appearance. For the most part, these males are colored in the same manner as the females, except in that they are more broadly streaked above and below and have wings and wing shoulders with the morphology of the breeding class of males. Rarely, males in the non-breeding class have elongated brownish black tail feathers, though these feathers are substantially shorter than those of the breeding class. Immature males and females are very similar in appearance to the adult female. However, immature males, much like adult non-breeding males, are slightly larger than adult females. The length of a female starts at 15cm and males have been recorded at 71cm in length, which has their tail included. Male weigh between 33–46 g and females weigh between 25–39 g.

Distribution and habitat

There are three known isolated populations of long-tailed widowbirds. The first is found in the Kenyan highlands, the second in

Angola , national_anthem = "Angola Avante"() , image_map = , map_caption = , capital = Luanda , religion = , religion_year = 2020 , religion_ref = , coordina ...

, southern

Zaire Zaire (, ), officially the Republic of Zaire (french: République du Zaïre, link=no, ), was a Congolese state from 1971 to 1997 in Central Africa that was previously and is now again known as the Democratic Republic of the Congo. Zaire was, ...

and

, and the third in

southern Africa Southern Africa is the southernmost subregion of the African continent, south of the Congo and Tanzania. The physical location is the large part of Africa to the south of the extensive Congo River basin. Southern Africa is home to a number ...

. It is unknown when these populations were last in contact, however, and the central population differs most in morphology relative to the other two populations.Craig, A. (1980) "Behaviour and evolution in the genus Euplectes." '' Journal of Ornithology'', 121: 144–161. The southern African population extends from the Eastern Cape (Transkei region) through the Free State, Lesotho,

KwaZulu-Natal KwaZulu-Natal (, also referred to as KZN and known as "the garden province") is a province of South Africa that was created in 1994 when the Zulu bantustan of KwaZulu ("Place of the Zulu" in Zulu) and Natal Province were merged. It is loca ...

, and western Eswatini to the Transvaal plateau. The species just enters southeastern

, but is most commonly found in the central highveld of South Africa. Long-tailed widowbirds are generally found in swampy grassland in flocks consisting of one or two males and a number of females. The males fly with their tails drooping and somewhat spread, and with slow regular movements of their wings. In wet weather, they are unable to fly due to their elongated tails. During the non-breeding season, long-tailed widowbirds congregate into flocks, which can be found roosting in reed beds. The long-tailed widowbird can be found at elevations up to 2,750 metres (9,022 feet) in the Drakensberg Mountains.Andersson, Malte. (1994). ''Sexual Selection''. Princeton University Press; Princeton, NJ: pp. 112–117. Long-tailed widowbirds showing breeding and non-breeding plumage

Long-tailed widowbirds showing breeding and non-breeding plumage

Behaviour

Food and feeding

The long-tailed widowbird's diet generally consists of seeds, supplemented occasionally by arthropods. The birds do most of their foraging in flocks on the ground, though they are occasionally observed hawking insects airily. The long-tailed widowbird feeds on a distinct variety of seeds, including those of '' Setaria sphacelata'' (twisted-leaf bristle grass), '' Paspalum dilatatum'' (common paspalum), ''

Paspalum distichum ''Paspalum distichum'' is a species of grass. Common names include knotgrass, water finger-grass, couch paspalum, eternity grass, gingergrass, and Thompson grass. Its native range is obscure because it has long been present on most continents, a ...

'' (couch paspalum), '' Pennisetum clandestinum'' (Kikuyu grass), ''

Triticum Wheat is a grass widely cultivated for its seed, a cereal grain that is a worldwide staple food. The many species of wheat together make up the genus ''Triticum'' ; the most widely grown is common wheat (''T. aestivum''). The archaeologi ...

'' (wheat), '' Themeda triandra'' (rooigras), and ''

Senecio juniperinus ''Senecio'' is a genus of flowering plants in the daisy family ( Asteraceae) that includes ragworts and groundsels. Variously circumscribed taxonomically, the genus ''Senecio'' is one of the largest genera of flowering plants. Description Mo ...

'' (groundsel). They also feed upon both insects, including species of beetles (

Coleoptera Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 describ ...

), cicadas and aphids ( Hemiptera), and

spiders Spiders (order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species di ...

Breeding

Males defend territories in the grasslands the species inhabits. Females have a long nesting period and survey these territories and the males that inhabit them prior to mate selection. Breeding takes place from February to July, reaching its peak in March and April. Females weave nests, shaped in large dome structures with a lining of seedheads, in the high grass within males' territories. The nests are placed 0.5–1 meters (19 to 40 inches) off the ground in the upper third of the high grass (''

Eleusine jaegeri ''Eleusine'' is a genus of Asian, African, and South American plants in the grass family, Females often mate with the male within whose territories they nest. Females lay one to three eggs after mating, and these are pale bluish green and streaked with brown. They are usually around 23.5 millimeters (0.9 inches) by 16.5 mm (0.6 inches) in size.

Sexual selection

Charles Darwin Charles Robert Darwin ( ; 12 February 1809 – 19 April 1882) was an English natural history#Before 1900, naturalist, geologist, and biologist, widely known for his contributions to evolutionary biology. His proposition that all speci ...

first expressed his ideas on sexual selection and

mate choice Mate choice is one of the primary mechanisms under which evolution can occur. It is characterized by a "selective response by animals to particular stimuli" which can be observed as behavior.Bateson, Paul Patrick Gordon. "Mate Choice." Mate Choic ...

in his book ''

The Descent of Man, and Selection in Relation to Sex ''The Descent of Man, and Selection in Relation to Sex'' is a book by English naturalist Charles Darwin, first published in 1871, which applies evolutionary theory to human evolution, and details his theory of sexual selection, a form of biolo ...

'' in 1871 in response to questions surrounding the elaborate ornamentation that males of some species exhibit despite detrimental costs to survival and seemingly negative consequences for reproductive success.Darwin, C. (1871). ''The Descent of Man, and Selection in Relation to Sex''. John Murray; London. He proposed two explanations for such traits' existences: these traits are useful in male-male combat or are preferred by females. Relative to the first of Darwin's theories on sexual selection, the process of female choice, though theoretically plausible, took a considerable amount of time to gain acceptance because Darwin had little, if any, firm evidence that females did in fact choose mates based on characteristics they found attractive. It took ninety years after Darwin's initial proposal for the theory to be tested in what has become a classic example of behavioral ecology research.Davies N, Krebs J, and West S. (2012). ''An Introduction to Behavioral Ecology'', 4th Ed. Wiley-Blackwell; Oxford: pp. 188–192. The male long-tailed widowbird has one of the most remarkable ornaments among

passerine A passerine () is any bird of the order Passeriformes (; from Latin 'sparrow' and '-shaped'), which includes more than half of all bird species. Sometimes known as perching birds, passerines are distinguished from other orders of birds by th ...

birds. Their tails, which are often more than half a meter (20 inches) long, are the most extreme sexual ornament among ''Euplectes'' and seem to in fact be detrimental to the survival of the male. Thus, the tail appears to oppose forces of natural selection in the basic sense by decreasing survival in individuals who carry the trait. It was for this reason that researchers have chosen to focus their research into female choice on the confusing example of the long-tailed widowbird.

Andersson experiment

Malte Andersson and colleagues tested Darwin's (and Fisher's) theory of female preference for ornamentation as the cause of extreme elongation of the male long-tailed widowbird's tail. They changed the length of males' tails and studied their relative mating success. Early in the breeding season, the territories of thirty-six males were mapped and the numbers of nests were counted. The experimenters used each male as his own control by subtracting the number of nests in each male's territory before treatment from the total of nests after treatment. This reduced the influence of initial variation among male territories on the outcome of the experiment. In a randomized block experiment, the color-ringed males were partitioned among nine groups of four males each. These groups were similar in territory quality and tail length. The tail of one randomly selected male within each group was cut to about 14 centimeters (5 inches) in length. Each removed feather was then glued to the corresponding feather of another male, elongating his tail by 20 to 30 centimeters (8 to 12 inches). The two other males in the group served as controls. One had his tail cut and repaired using glue, while the other's tail was left unchanged. A clear pattern of success emerged, with males with the elongated tails being the most successful, followed by the control (normal tail length) males, followed by the males with shortened tails. The result indicated that the long tail is favored by sexual selection through female choice of mates. Female preference for long tails is also seen in the

red-collared widowbird The red-collared widowbird (''Euplectes ardens'') is a species of bird in the family Ploceidae. Red-collared widowbirds are found in grasslands and bush clearings in Eastern and Southern Africa. They are known for their long tails and brilliant ...

.Pryke, S., Andersson, S. and Lawes, M. (2001). "Sexual Selection of Multiple Handicaps in the Red-Collared Widowbird: Female Choice of Tail Length but not Carotenoid Display". ''Evolution'' 55 (7): 1452–1463 The Andersson experiment demonstrated that female long-tailed widowbirds prefer supernormal tails, as males with elongated tails were found to be the most reproductively successful. The tail females found most attractive were longer than those that occur in the natural setting. This outcome was shown to be the result of female choice rather than differences in male behavior resulting from shortened tails: males with shortened tails neither became less active in courtship display, nor did they give up their breeding territories. Thus, the tail is used to attract females rather than in direct contests among males, which is further supported by the fact that males do not expand their tails during flight displays during territorial contests.

Males' tail and epaulet

Shoulder epaulet of breeding male One explanation for why females favor long tails in males is that the expanded tail enlarges the lateral surface area of the male by 2–3 times, making him much more visible from far distances over open grassland. However, this is most likely not the whole explanation, especially considering that prior to mating, females spend a great deal of time comparing males and, thus, do not rely on sighting them from a distance. As of this time, the exact function of

epaulet Epaulette (; also spelled epaulet) is a type of ornamental shoulder piece or decoration used as insignia of rank by armed forces and other organizations. Flexible metal epaulettes (usually made from brass) are referred to as ''shoulder scales'' ...

in male long-tailed widowbirds is unknown. However, its use does resemble that of the

red-winged blackbird The red-winged blackbird (''Agelaius phoeniceus'') is a passerine bird of the family Icteridae found in most of North America and much of Central America. It breeds from Alaska and Newfoundland and Labrador, Newfoundland south to Florida, the Gu ...

, being displayed during courtship and threat displays. Thus, the two most conspicuous ornaments of the male birds in the two species may be favored by different forms of sexual selection: the tail of the long-tailed widowbird by female choice and the brightly colored epaulets of the long-tailed widowbird and red-winged blackbird by male contest competition.

Conservation status

The long-tailed widowbird has a very large range, and so the species would not be classified as vulnerable under the range size criterion put forward by BirdLife International which include that the extent of occurrence being less than 20,000 km² (7722 miles²) combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation.BirdLife International. (2012). Species factsheet: Euplectes progne. Downloaded from http://www.birdlife.org on 15/12/2012. The population is stable according to the population trend criterion, which requires a greater than 30% decline over ten years or three generations, and would not be considered vulnerable for this reason. While the total population size has not yet been quantified, it is not believed that the long-tailed widowbird is approaching the threshold for being considered vulnerable under the population size criterion (less than 10,000 mature individuals with a continuing decline estimated to be greater than 10% in ten years or three generations, or with a specified population structure). For these reasons, the species is evaluated as least concern.

Gallery

Female Long-tailed Widowbird.jpeg, Female Euplectes progne.jpg, Immature male beginning to transition to adult plumage Longtailed Widowbird, Euplectes progne changing from winter to summer breading plumage at Rietvlei Nature Reserve, South Africa (10073140484).jpg, Further transition into adult plumage Male Long-tailed Widowbird.jpeg, Breeding male on territory

References

External links

* Long-tailed widow �
Species text in The Atlas of Southern African Birds
{{Taxonbar, from=Q577664

long-tailed widowbird The long-tailed widowbird (''Euplectes progne''), also known as the "sakabula", is a species of bird in the family Ploceidae.Mackworth-Praed, C.W., and C.H. Grant. (1960). ''Birds of Eastern and North Eastern Africa''. Longmans, Green and Co LTD. ...

Birds of East Africa Birds of Southern Africa

Taxonomy articles created by Polbot