Arabian babbler

Arabian babbler
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Passeriformes
Family: Leiothrichidae
Genus: Turdoides
Species: T. squamiceps
Binomial name
Turdoides squamiceps
(Cretzschmar, 1827)

The Arabian babbler (Turdoides squamiceps) is a passerine bird belonging to 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.

Taxonomy

The Arabian babbler is one of the 26 species of the genus Turdoides that constitutes together with several other genera the family Leiothrichidae. The Leiothrichidae primarily occur in the Ethiopian and Oriental ecozones, but a few species of the genus Turdoides have penetrated into the Palearctic zone north of the tropics where they live in arid areas of North and East Africa, India and the Middle East.[2]

Description

It is 26 to 29 centimetres (10 to 11 in) long with a wingspan of 31 to 33.5 centimetres (12.2 to 13.2 in) and a weight of 64 to 83 grams (2.3 to 2.9 oz). It has a fairly long curved bill, a long tail, rounded wings and strong legs and feet. The plumage is grey-brown above, paler below. There are dark streaks on the back and the throat is whitish. It has a variety of calls including whistles, trills and chattering.

Distribution and habitat

The Arabian babbler prefers to settle along dry river beds with few trees and bushes. It is found in eastern, southern and western Arabia, occurring in the United Arab Emirates, Oman, Yemen and western Saudi Arabia but absent from the central and north-eastern parts of the peninsula. Its range extends north to Jordan, Israel and eastern Sinai. It inhabits arid scrubland and savanna, occurring up to 2800 metres above sea-level in Yemen.

Behaviour

Photographed at Al Ain, Abu Dhabi, UAE

Babblers dance and take baths together, offer each other gifts, clean themselves, and sometimes enter into conflict with each other for the privilege of helping another babbler. They may also feed their counterparts. This peculiar behaviour made them a privileged example for ethological theories concerning altruism among animals.

Starting in the 1970s, Amotz Zahavi observed the babbler at length, giving rise to his theory of signal and its correlative, the handicap principle. Although babblers were considered particularly altruistic animals, Zahavi reinterpreted their behaviours according to his theory. Thus, Zahavi (1974) theorized that chick feeding by Arabian babbler helpers acts as a signal by the helper to gain social prestige within the group.[3][4]

Group structure and breeding biology

Arabian babblers are cooperative breeders that live in groups and defend territories year round. Group size varies from two to 10 individuals. Their territories vary with the group size as well the presence of neighboring groups. Groups consist of a reproductive pair and other non-breeding members who may or may not be direct offspring or close relatives. Helpers usually do not reproduce, but they participate in rearing the offspring, that is, in providing food, as well as other parental behavior like incubation, territory defense and defense against predators.[5]

Groups are labelled according to the relatedness of helpers to the reproductive pair:

  1. Simple group: where all helpers are direct offspring of the breeding pairs.
  2. Polyandrous group: where helpers include potential male breeder
  3. Polygynous group: where helpers include potential female breeders
  4. Complex group: Have non-related helpers of both sexes.

Nest

Babblers build open cup-shaped nests in the dense part of the tree or bush. Their breeding period starts generally from February and varies up to July and is highly dependent on the seasonal rainfall of the region which in turn regulates the food availability. They copulate throughout the year. Eggs are laid usually from February to July. Most clutches contain four eggs, laid on consecutive days. Incubation usually starts after laying the last egg and continues for 14 days until the chicks hatch.[6] The nestlings fledge about 14 days after hatching.[7]

Diet

The diet of the babblers includes a variety of invertebrates (mostly arthropods), small vertebrates (lizards, geckos, snakes) and plant material, like nectar, flowers, berries, leaves and seeds.[2][8]

References

  1. ↑ BirdLife International (2012). "Turdoides squamiceps". IUCN Red List of Threatened Species. Version 2013.2. International Union for Conservation of Nature. Retrieved 26 November 2013.
  2. 1 2 Zahavi, A. (1990). "Arabian Babblers: The quest for social status in a cooperative Breeder", pp. 105–130 in Cooperative Breeding in Birds, P. B. Stacey and W. D. Koenig (eds.), Cambridge University Press, Cambridge, United Kingdom
  3. ↑ Anava, A.; Kam, M.; Shkolnik, A.; Degen, A.A. (2001). "Does group size affect field metabolic rate of Arabian Babbler (Turdoides squamiceps) nestlings?". The Auk 118: 525–528. JSTOR 4089815.
  4. ↑ Zahavi A. (1974). "Communal nesting by the Arabian Babbler: A case of individual selection". Ibis 116: 84–87. doi:10.1111/j.1474-919X.1974.tb00225.x.
  5. ↑ Lundy, K.J.; Parker, P.G.; Zahavi, A. (1998). "Reproduction by subordinates in cooperatively breeding Arabian babblers is uncommon but predictable". Behavioral Ecology and Sociobiology 43 (3): 173–180. doi:10.1007/s002650050478.
  6. ↑ Ostreiher, R. (2001). "The importance of nestling location for obtaining food in open cup-nests". Behavioral Ecology and Sociobiology 49 (5): 340. doi:10.1007/s002650000308.
  7. ↑ Ostreiher, R. (1997). "Food division in the Arabian babbler nest: adult choice or nestling competition?". Behavioral Ecology 8 (2): 233. doi:10.1093/beheco/8.2.233.
  8. ↑ Cramp, S. and Perrins, C. (1993) Handbook of the birds of Europe, the Middle East and North Africa: the birds of the Western Palearctic: Flycatchers to Shrikes. Volume 8. Oxford, Oxford University Press.

Bibliography

External links

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