Saddle-billed stork

Saddle-billed stork
Adult male in Kruger National Park, South Africa
Female in Masai Mara, Kenya – irises are yellow
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Ciconiiformes
Family: Ciconiidae
Genus: Ephippiorhynchus
Species:
E. senegalensis
Binomial name
Ephippiorhynchus senegalensis
(Shaw, 1800)
Synonyms[2]

Mycteria senegalensis Shaw, 1800

The saddle-billed stork or saddlebill (Ephippiorhynchus senegalensis) is a large wading bird in the stork family, Ciconiidae. It is a widespread species which is a resident breeder in sub-Saharan Africa from Sudan, Ethiopia and Kenya south to South Africa, and in The Gambia, Senegal, Côte d'Ivoire and Chad in west Africa.[3] It is considered endangered in South Africa.

It is a close relative of the widespread Asian and Australian black-necked stork, the only other member of the genus Ephippiorhynchus.

Description

In flight
Head of male showing distinctive iris and yellow wattles, Zambia

This is a huge bird that regularly attains a height of 145 to 150 cm (4 ft 9 in to 4 ft 11 in), a length of 142 cm (4 ft 8 in) and a 2.4 to 2.7 m (7 ft 10 in to 8 ft 10 in) wingspan.[4] While heights published have been in the aforementioned narrow range, reportedly adult saddle-billed storks in captivity can attain a height of up to 150 to 180 cm (4 ft 11 in to 5 ft 11 in).[5] The male is larger and heavier than the female, with a range of 5.1–7.52 kg (11.2–16.6 lb), with a mean mass of 6.38 kg (14.1 lb). The female is usually between 5 and 6.84 kg (11.0 and 15.1 lb), with a mean mass of 5.95 kg (13.1 lb).[6] Among the large storks, the saddle-billed broadly overlap in size with the two larger Leptoptilos and the Jabiru stork but possesses a longer, more slender neck and slightly longer legs than the other largest storks, so the saddle-billed is likely to be the tallest extant species of the family.[7] Its extremely long legs measure up to 36.5 cm (14.4 in)) in tarsus length. The long bill measures from 27.3 to 36 cm (10.7 to 14.2 in).[7] The sexes can be readily distinguished by the golden yellow irises of the female and the brown irises and dangling yellow wattles of the male. It is therefore one of the few storks to display sexual dimorphism in colour.[8]

Front view showing red patch on chest, Zambia

It is spectacularly plumaged; both the female and male appear identical when perched but the female shows much more white in the primaries in flight. The head, neck, back, wings, and tail are iridescent black, with the rest of the body and the primary flight feathers being white. Juveniles are browner grey in plumage. The massive bill is red with a black band and a yellow frontal shield (the "saddle"). The legs and feet are black with pink hocks. On the chest is a bare red patch of skin, whose colour darkens during breeding season.[9]

Behaviour

They are silent except for bill-clattering at the nest. Like most storks, they fly with the neck outstretched, not retracted like a heron; in flight, the large heavy bill is kept drooping somewhat below belly height, giving these birds a distinctive appearance. This makes them easily recognizable, even if seen from a distance. It has been suggested that due to the large size and unusual appearance in flight, this species is the basis for the "big bird" and kongamato cryptids.

Habitat

At the continental scale, saddle-billed storks preferred protected areas that have a higher extent of open water compared to areas without other storks.[3] Some of these trends may, however, be due to a bias in coverage by ornithologists of safer areas such as national parks and protected swamps that afford easier accessibility and comforts.

Breeding

The saddle-billed storks are solitary nesters, building massive nest platforms that are used repeatedly in successive seasons. Unlike many other storks, these species are often seen in pairs in the nonbreeding season suggesting a lifelong pair bond.[10] They breed in forested wetlands and other floodplains in tropical lowlands. It builds a large, deep stick nest in a tree, laying one to five (typically two or three)[11] white eggs weighing about 146 g (5.1 oz) each. The incubation period is 30–35 days, with another 70–100 days before the chicks fledge, with the young often remaining in the parents' territory until the next breeding season.[12]

Food and feeding

Fishing in Botswana
Male trying to swallow a Catfish, Mapungubwe National Park, South Africa

The saddle-billed stork searches for prey by stabbing the bill into the water, catching prey by contact, and in the same way into mud and vegetation.It also hunts by visual detection. In one study with 255 minutes of observation, 71% of successful catches were due to visual foraging, and 29% due to tactile foraging.[13] They usually feed on aquatic prey such as fish lungfish (Protopterus spp.) and catfish (Clarias spp.), up to 1.3 kg (2.9 lb) in weight.[7] It swallows the fish head first and then drinks some water.[14] In the case of large fish prey, they are often taken to the shore where pectoral fins may be clipped off before the fish is swallowed head first.[15] Saddle-billed storks opportunistically catch other prey such as frogs, snails, small mammals, birds, snakes, and insects such as grasshoppers, termites, and water beetles.[14] In an unusual case, the saddle-billed stork killed and consumed a red-billed Duck (Anas erythrorhyncha) and a spitting cobra (Naja mossambica). An unsuccessful attack on the slender mongoose (Galerella sanguinea) has been reported.[14]

Relation to Ancient Egyptian culture

This bird is represented in an Ancient Egyptian hieroglyph (Gardiner G29) that had the phonetic value "bꜣ":

G29

[16] Its description is often erroneously given as "jabiru", which is a South American relative. The Third Dynasty pharaoh Khaba incorporated this hieroglyph in his name (Jiménez Serrano 2002). The first depictions of the species come from depictions during the Late Predynastic Period (pre-3150 B.C.), and trends in depictions have been useful to deduce a decline in the species' range from ancient Egypt likely due to intensifying urbanisation and an increasingly arid climate (c. 2686–2181 BC).[17][18][3]

References

  1. ^ BirdLife International (2016). "Ephippiorhynchus senegalensis". IUCN Red List of Threatened Species. 2016: e.T22697706A93631820. doi:10.2305/IUCN.UK.2016-3.RLTS.T22697706A93631820.en. Retrieved 13 November 2021.
  2. ^ Elliott, A.; Garcia, E.F.J. & Boesman, P. (2018). del Hoyo, J.; Elliott, A.; Sargatal, J.; Christie, D.A. & de Juana, E. (eds.). "Saddlebill (Ephippiorhynchus senegalensis)". Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. Retrieved 24 December 2018.
  3. ^ a b c Gula, Jonah; Weckerly, Floyd; Sundar, K.S. Gopi (2019). "The first range-wide assessment of Saddle-billed Stork Ephippiorhynchus senegalensis distribution". Ostrich. 90 (4): 347–357. Bibcode:2019Ostri..90..347G. doi:10.2989/00306525.2019.1696900.
  4. ^ Borrow, N., & Demey, R. (2013). Birds of Senegal and the Gambia. Bloomsbury Publishing.
  5. ^ Womack, D. Dallas Zoo, AZA Saddle-billed Stork SSP Coordinator and Regional Studbook Keeper.
  6. ^ Dunning, John B. Jr., ed. (2008). CRC Handbook of Avian Body Masses (2nd ed.). CRC Press. ISBN 978-1-4200-6444-5.
  7. ^ a b c Hancock & Kushan, Storks, Ibises and Spoonbills of the World. Princeton University Press (1992), ISBN 978-0-12-322730-0
  8. ^ Elliott, A., E. F. J. Garcia, and P. F. D. Boesman (2020). Saddle-billed Stork (Ephippiorhynchus senegalensis), version 1.0. In Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA.
  9. ^ "San Diego Zoo file" (PDF). Archived from the original (PDF) on 2011-07-22. Retrieved 2011-01-13. (477 KB)
  10. ^ Kahl, M. P. "Comparative ethology of the Ciconiidae. Part 6. The black-necked, saddlebill, and jabiru storks (genera Xenorhynchus, Ephippiorhynchus, and Jabiru)." The Condor 75.1 (1973): 17-27.
  11. ^ Womack, Jocelyn. ""Saddle-billed stork species fact sheet"" (PDF). ASAG. Retrieved 9 February 2021.
  12. ^ Bouglouan, Nicole. "Saddle-billed stork". oiseaux-birds.com. Retrieved 25 October 2021.
  13. ^ Gula, Jonah; Mungole, Amukena (2022). "Foraging of Saddle-billed Storks Ephippiorhynchus senegalensis during the dry season in western Zambia" (PDF). SIS Conservation. 4: 10–14.
  14. ^ a b c Gula, J. (2021). Saddle-billed Stork (Ephippiorhynchus senegalensis), version 2.0. In Birds of the World (S. M. Billerman and B. K. Keeney, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.sabsto1.02
  15. ^ Morris, A. (1979). Saddlebill fishing methods. Honeyguide 98:33.
  16. ^ Allen, James (2014). Middle Egyptian: An Introduction to the Language and Culture of Hieroglyphs (3 ed.). Cambridge: Cambridge University Press. p. 480. ISBN 978-1-107-66328-2.
  17. ^ Janák, J. (2011). "Spotting the Akh: the presence of the Northern Bald Ibis in ancient Egypt and its early decline". Journal of the American Research Center in Egypt. 46: 17–31. JSTOR 41431566.
  18. ^ Janák, J. (2014). "Saddle-billed Stork (ba-bird)". UCLA Encyclopedia of Egyptology 1. UCLA. pp. 1–8.

Further reading

  • Barlow, Clive (1997): A field guide to birds of the Gambia and Senegal. Pica Press, Nr. Robertsbridge (East Sussex). ISBN 1-873403-32-1
  • Jiménez Serrano, Alejandro (2002): Royal Festivals in the Late Predynastic Period and the First Dynasty. British Archaeological Reports (International Series) 1076. ISBN 1-84171-455-0
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