Southern pied babbler | |
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At Marakele N. P., South Africa | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Passeriformes |
Family: | Leiothrichidae |
Genus: | Turdoides |
Species: | T. bicolor |
Binomial name | |
Turdoides bicolor (Jardine, 1831) | |
The southern pied babbler (Turdoides bicolor) is a species of bird in the family Leiothrichidae, found in dry savannah of Botswana, Namibia, South Africa, and Zimbabwe.
The southern pied babbler is a medium-sized 75 to 95 grams (2.6 to 3.4 oz) cooperatively breeding passerine bird. Groups range in size from 2-16 adults, but pairs are rare. The species is sexually monomorphic, with males and females indistinguishable from physical characteristics. Each group comprises a dominant breeding pair that monopolise access to breeding opportunities. [2] Recent genetic research has confirmed that these dominant pairs are responsible for more than 95% of young hatched. [2] Occasional mixed parentage has been observed, but is predictable in most cases: subordinates primarily gain parentage when a new (unrelated) immigrant disperses into the group, or a new group is founded. [2] All group members cooperate to help raise the young hatched from a single clutch. Clutch size varies between two and five, with a modal clutch size of three.
Cooperative behaviours include: provisioning young (both in the nest and post-fledging), sentinel behaviour, territory border defense, teaching behaviour and babysitting behaviour (where semi-independent fledglings follow adults between foraging sites and away from predators). The breeding season extends from late-September to early April, although this varies between years and is strongly rain-dependent. Groups can raise up to three successful clutches per breeding season. Average incubation time is 14 days, and average time between hatching and fledging is 16 days. Fledging time varies according to group size: small groups tend to fledge their young earlier than large groups. [3] Post-fledging, young are poorly mobile, unable to fly, and rely entirely on adult group members for food. Fledgling foraging efficiency develops slowly, and fledglings can continue to be provisioned by adults for up to four months post-fledging. The amount of care that young receive during this stage has long-term effects: fledglings that receive care for the longest periods tend to be heavier and better foragers than their counterparts. In addition, they are more likely to successfully disperse from their natal group and consequently begin reproducing earlier than their “failed-disperser” counterparts. [4]
Aggression toward fledglings is most commonly observed when the dominant pair have begun to incubate another brood. During this period, begging fledglings will be punished by parents using aggressive behaviour such as jumping on the youngster. [3] In all cases, fledglings stop begging immediately following attack. Brood overlap results in a distinctive division of labour, with subordinate adults continuing to care for fledglings while the dominant pair concentrate their effort on the new brood. Owing to the extended period of post-fledging care in this species, this can result in dependent young from multiple broods being raised simultaneously.
Pied babblers are strongly territorial, and defend their borders using wing and vocal displays on a near daily basis. These fights rarely lead to physical aggression and injury from such fights is very rare. Groups defend the same territory year-round and small groups tend to lose portions of their territory to larger neighbouring groups.
Research on pied babblers has provided the first evidence of teaching behaviour in an avian species. [5] Pied babblers teach their young by giving a specific purr call each time they deliver food. Young learn to associate this call with food and reach out of the nest each time they hear it. Adults exploit this association to encourage young to fledge by giving the purr call at a distance from the nest, enticing young to follow them. [6] Post-fledging, adults continue to use the call to encourage young to move between foraging areas or away from predators. This call is also used to recruit independent fledglings to a rich foraging site, [7] and may thus provide young with information on where to forage to locate rich food sources.
Research on pied babblers reveals that temperatures exceeding 38°C compared to moderate, more normal ones of 23°C, can halve their ability to learn associations, research which its authors suggest raises another factor about climate change that will impact on wildlife survival. [8]
Research on pied babblers has also provided evidence of task partitioning behaviour. [9] In this species, the dominant pair are able to leave their dependent young in the care of helpers and initiate a new brood. This allows brood overlap: several broods of dependent young can be raised at the same time. Such a behaviour highlights the benefits of cooperative breeding: many helpers allow breeders to invest in more broods. Parents initiate this task partitioning by aggressively punishing offspring that beg at them for food. [10] This repeated punishment results in young fledglings begging for food from helpers rather than their parents: freeing up their parents to breed again. [10]
Pied babblers have a complex interspecific interaction with the kleptoparasitic fork-tailed drongo, Dicrurus adsimilis . Drongos perch above and follow babbler groups between foraging sites and give alarm calls each time a predator is seen. When drongos are present, babblers invest less time in sentinel behaviour. However, drongos occasionally give false alarm calls and then swoop down to steal the food items that the foraging babblers have dropped upon hearing an alarm call. To avoid the cost of kleptoparasitism, large babbler groups, which have enough group members to participate in sentinel behaviour, do not tolerate drongos and aggressively chase them away from the group. Consequently, they suffer very few losses to kleptoparasitic attack. However, small groups do not have enough group members to provide sentinel behaviour without affecting time invested in other behaviours such as foraging or provisioning young. These groups therefore tolerate occasional kleptoparasitic attacks in return for the sentinel duties that drongos provide. [11]
Young pied babblers have difficulty handling larger food items such as scorpions, skinks and solifuges, and take a lot longer to break these food items down than adults. [12] This makes them ideal victims for attacks by fork-tailed drongos: research has revealed that drongos specifically target young babblers for kleptoparasitic attacks and gain greater foraging success by doing so. [12]
The Pied Babbler Research Project was established by Dr Amanda Ridley in 2003 for the purpose of studying many aspects of cooperative breeding behaviour over the long-term. [12] The population comprises fully habituated groups of wild pied babblers. The average number of groups in the population varies between 10-18 each year. Research is conducted continuously by scientists and postgraduate students and involves investigations into population dynamics, the causes and consequences of helping behaviour, sexual selection, foraging ecology, interspecific interactions, vocal communication, parent-offspring conflict, kin recognition, maternal effects, physiology and reproductive conflict. [13]
Individuals appear to avoid inbreeding in two ways. The first is through dispersal, and the second is by avoiding familiar group members as mates. [14] Although both males and females disperse locally, they move outside the range within which genetically related individuals are likely to be encountered. Within their group, individuals only acquire breeding positions when the opposite-sex breeder is unrelated. In general, inbreeding is avoided because it leads to a reduction in progeny fitness (inbreeding depression) due largely to the homozygous expression of deleterious recessive alleles. [15]
The Pomatostomidae are small to medium-sized birds endemic to Australia-New Guinea. For many years, the Australo-Papuan babblers were classified, rather uncertainly, with the Old World babblers (Timaliidae), on the grounds of similar appearance and habits. More recent research, however, indicates that they are too basal to belong the Passerida – let alone the Sylvioidea where the Old World babblers are placed – and they are now classed as a separate family close to the Orthonychidae (logrunners). Five species in two genus are currently recognised, although the red-breasted subspecies rubeculus of the grey-crowned babbler may prove to be a separate species.
The long-tailed tit, also named long-tailed bushtit, is a common bird found throughout Europe and the Palearctic. The genus name Aegithalos was a term used by Aristotle for some European tits, including the long-tailed tit.
The Australian zebra finch is the most common estrildid finch of Central Australia. It ranges over most of the continent, avoiding only the cool humid south and some areas of the tropical far north. The bird has been introduced to Puerto Rico and Portugal. Due to the ease of keeping and breeding the zebra finch in captivity, it has become Australia's most widely studied bird; by 2010, it was the most studied captive model passerine species worldwide, by a considerable margin.
The grasshopper sparrow is a small New World sparrow. It belongs to the genus Ammodramus, which contains three species that inhabit grasslands and prairies. Grasshopper sparrows are sometimes found in crop fields and they will readily colonize reclaimed grassland. In the core of their range, grasshopper sparrows are dependent upon large areas of grassland where they avoid trees and shrubs. They seek out heterogenous patches of prairie that contain clumps of dead grass or other vegetation where they conceal their nest, and also contain barer ground where they forage for insects, spiders, and seeds. Grasshopper sparrows are unusual among New World sparrows in that they sing two distinct song types, the prevalence of which varies with the nesting cycle. The primary male song, a high trill preceded by a stereotyped series of short chips, is reminiscent of the sounds of grasshoppers and is the origin of this species' name. Like some other birds of the central North American grasslands, this species also moves around a lot, not only via annual migrations, but individuals frequently disperse between breeding attempts or breeding seasons. Grasshopper sparrows are in steep decline across their range, even in the core of the breeding distribution in the tallgrass prairies of the central Great Plains. The Florida grasshopper sparrow is highly endangered.
The fork-tailed drongo, also called the common drongo or African drongo, is a small bird found from the Sahel to South Africa that lives in wooded habitats, particularly woodlands and savannas. It is part of the family Dicruridae and has four recognized subspecies, D. a adsimilis, D. a. apivorus, D. a. fugax and D. a. jubaensis. Like other drongos, the fork-tailed is mostly insectivorous; its diet mainly consists of butterflies, termites, and grasshoppers.
The Jacobin cuckoo, also pied cuckoo or pied crested cuckoo, is a member of the cuckoo order of birds that is found in Africa and Asia. It is partially migratory and in India, it has been considered a harbinger of the monsoon rains due to the timing of its arrival. It has been associated with a bird in Indian mythology and poetry, known as the chātaka represented as a bird with a beak on its head that waits for rains to quench its thirst.
The jungle babbler is a member of the family Leiothrichidae found in the Indian subcontinent. Jungle babblers are gregarious birds that forage in small groups of six to ten birds, a habit that has given them the popular name of "Seven Sisters" in urban Northern India, and in Bengali, with cognates in other regional languages which also mean "seven brothers".
The yellow-billed babbler is a member of the family Leiothrichidae endemic to southern India and Sri Lanka. The yellow-billed babbler is a common resident breeding bird in Sri Lanka and southern India. Its habitat is scrub, cultivation and garden land. This species, like most babblers, is not migratory, and has short rounded wings and a weak flight and is usually seen calling and foraging in groups. It is often mistaken for the jungle babbler, whose range overlaps in parts of southern India, although it has a distinctive call and tends to be found in more vegetated habitats. Its name is also confused with Turdoides leucocephala, which is also known as white-headed babbler.
The black drongo is a small Asian passerine bird of the drongo family Dicruridae. It is a common resident breeder in much of tropical southern Asia from southwest Iran through Pakistan, India, Bangladesh and Sri Lanka east to southern China and Indonesia and accidental visitor of Japan. It is an all black bird with a distinctive forked tail and measures 28 cm (11 in) in length. It feeds on insects, and is common in open agricultural areas and light forest throughout its range, perching conspicuously on a bare perch or along power or telephone lines.
The Siberian jay is a small jay with a widespread distribution within the coniferous forests in North Eurasia. It has grey-brown plumage with a darker brown crown and a paler throat. It is rusty-red in a panel near the wing-bend, on the undertail coverts and on the sides of the tail. The sexes are similar. Although its habitat is being fragmented, it is a common bird with a very wide range so the International Union for Conservation of Nature has assessed its conservation status as being of "least concern".
Philopatry is the tendency of an organism to stay in or habitually return to a particular area. The causes of philopatry are numerous, but natal philopatry, where animals return to their birthplace to breed, may be the most common. The term derives from the Greek roots philo, "liking, loving" and patra, "fatherland", although in recent years the term has been applied to more than just the animal's birthplace. Recent usage refers to animals returning to the same area to breed despite not being born there, and migratory species that demonstrate site fidelity: reusing stopovers, staging points, and wintering grounds.
The large gray babbler is a member of the family Leiothrichidae found across India and far western Nepal. They are locally common in the scrub, open forest and gardenland. They are usually seen in small groups and are easily distinguished from other babblers in the region by their nasal call and the whitish outer feathers to their long tail. It is one of the largest babblers in the region.
The common babbler is a member of the family of Leiothrichidae. They are found in dry open scrub country mainly in India. Two populations are recognized as subspecies and the populations to the west of the Indus river system are now usually treated as a separate species, the Afghan babbler. The species is distinctly long-tailed, slim with an overall brown or greyish colour, streaked on the upper plumage and having a distinctive whitish throat.
Cooperative breeding is a social system characterized by alloparental care: offspring receive care not only from their parents, but also from additional group members, often called helpers. Cooperative breeding encompasses a wide variety of group structures, from a breeding pair with helpers that are offspring from a previous season, to groups with multiple breeding males and females (polygynandry) and helpers that are the adult offspring of some but not all of the breeders in the group, to groups in which helpers sometimes achieve co-breeding status by producing their own offspring as part of the group's brood. Cooperative breeding occurs across taxonomic groups including birds, mammals, fish, and insects.
The brown treecreeper is the largest Australasian treecreeper. The bird, endemic to eastern Australia, has a broad distribution, occupying areas from Cape York, Queensland, throughout New South Wales and Victoria to Port Augusta and the Flinders Ranges, South Australia. Prevalent nowadays between 16˚S and 38˚S, the population has contracted from the edges of its pre-European range, declining in Adelaide and Cape York. Found in a diverse range of habitats varying from coastal forests to mallee shrub-lands, the brown treecreeper often occupies eucalypt-dominated woodland habitats up to 1,000 metres (3,300 ft), avoiding areas with a dense shrubby understorey.
The Arabian babbler is a passerine bird until recently placed in the genus Turdoides. It is a communally nesting resident bird of arid scrub in the Middle East which lives together in relatively stable groups with strict orders of rank.
The chestnut-crowned babbler is a medium-sized bird that is endemic to arid and semi-arid areas of south-eastern Australia. It is a member of the family Pomatostomidae, which comprises five species of Australo-Papuan babblers. All are boisterous and highly social, living in groups of up to 23 individuals that forage and breed communally. Other names include red-capped babbler, rufous-crowned babbler and chatterer.
The black-lored babbler or Sharpe's pied-babbler is a species of bird in the family Leiothrichidae. It is found in southwestern Kenya, Tanzania, Uganda, Burundi, Rwanda, and the part of the Democratic Republic of the Congo immediately adjacent to the three last-named countries. This bird was formerly considered the same species as Turdoides melanops of southern Africa, now known as the black-faced babbler.
The term seabird is used for many families of birds in several orders that spend the majority of their lives at sea. Seabirds make up some, if not all, of the families in the following orders: Procellariiformes, Sphenisciformes, Pelecaniformes, and Charadriiformes. Many seabirds remain at sea for several consecutive years at a time, without ever seeing land. Breeding is the central purpose for seabirds to visit land. The breeding period is usually extremely protracted in many seabirds and may last over a year in some of the larger albatrosses; this is in stark contrast with passerine birds. Seabirds nest in single or mixed-species colonies of varying densities, mainly on offshore islands devoid of terrestrial predators. However, seabirds exhibit many unusual breeding behaviors during all stages of the reproductive cycle that are not extensively reported outside of the primary scientific literature.
Allofeeding is a type of food sharing behaviour observed in cooperatively breeding species of birds. Allofeeding refers to a parent, sibling or unrelated adult bird feeding altricial hatchlings, which are dependent on parental care for their survival. Allofeeding also refers to food sharing between adults of the same species. Allofeeding can occur between mates during mating rituals, courtship, egg laying or incubation, between peers of the same species, or as a form of parental care.