Biology:Abyssinian scimitarbill

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Short description: Species of bird

Abyssinian scimitarbill
Abyssinian scimitarbill Kenya.jpg
Adult bird in Laikipia, Kenya
Scientific classification edit
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Bucerotiformes
Family: Phoeniculidae
Genus: Rhinopomastus
Species:
R. minor
Binomial name
Rhinopomastus minor
(Rüppell, 1845)

The Abyssinian scimitarbill (Rhinopomastus minor) is a species of bird in the family Phoeniculidae. Abyssinia, is an old name for the region of Ethiopia, and scimitar refers to a curved sword, which its bill resembles. It is found in Djibouti, Ethiopia, Kenya, Somalia, South Sudan, Tanzania, and Uganda. The bird is non migratory, diurnal and terrestrial.[2] Their nests are sometimes parasitized by the greater honeyguide (Indicator indicator) species of bird which are favored by some people because of the way they can guide people to beehives.[3]

Description

The bird is all black with a blue-purple iridescence which covers the whole body and especially the back of the head. The birds beak is bright orange to red and is characteristically curved and pointed. It is slightly longer than the length of its head and is well built to probe into cracks and crevices for insects. It can be differentiated from other woodhoopoes by its all black legs and shorter tail (about the length of the bird’s body excluding its head).[4]

Sexual Dimorphism

The males coloring tends to be more blue, whereas the females have more brown tones especially in the head.[4] Males also tend to be a slightly larger than females. Their bill length is (Male: 3.33 cm; Female: 2.78 cm) Their tail length is (Male:10.7 cm; Female: 9.5 cm). Their body mass is around 22-28g with the males being on the heavier end.[5]

Taxonomy

The bird is the smallest of the group of Scimitarbills (genus Rhinopomastus) which contain three other species.[6] They are in the family of woodhoopoes (Phoeniculidae). It is in the order of (Bucerotiformes) which contains the hornbills, ground hornbills, hoopoes and wood hoopoes[7]

Habitat and Distribution

The bird is found commonly in open bushed, and dry savanna habitats and is an uncommon resident or thornscrub in low altitudes below 1400m (intermediate biome between a dessert and tropical forest).[8]

There are two subspecies which occupy different ranges of Africa. The Rhinopomastus minor minor occurs on the eastern edge of Africa Ethiopia to Somalia and Kenya, and Rhinopomastus minor cabsanisi occurs further west in Sudan to Ethiopia, Kenya and Tanzania.[6] See range map

Distribution

The species has a breeding range is around the equator with minimum to maximum latitudes of -9.01 to 11.78 degrees.[6]

The species has a combined total of around 20 000km2 of territorial range, although this area is largely fragmented.[9] While the population is declining, it appears to be at a rate of only 5% over three generations and therefore the bird is considered of least concern.[2]

Behavior

Vocalizations

The Abyssian Scimitarbill Rhinopomastus minor and the Common Scimitarbill Rhinopomastus cyanomelas both emit sharp cries and an unpleasant odor to deter predators (Hedley & Caro, 2022). Their warning calls sound like a series of rising notes "dok"[4] Other calls sound like shrill elongated chirps which rise and then fall minutely in pitch over the course of around eight to twelve chirps. Their song sounds similar to their calls, but with more silence between chirps. Listen here

Diet

The bird is insectivorous and eats mostly adult and live insects such as beetles, larvae, caterpillars, ants, flies and wasps. They will also eat seeds and berries. While much research has been done on the species, it has been observed to nest in abandoned bee nests, although it does not consume honey or other bee products.[3]

Reproduction

The bird is a monogamous solitary nester. The age of their first breeding is on average 1.23 years with an average clutch size of 2.5 eggs. The adults have an annual survival rate of 0.66 and the average length of a generation is 2.89 years.[2] They typically nest in holes or fissures, sometimes excavated by other species. This includes holes in trees and sometimes abandoned bees’ nests that are found a height of around 0.5-2m from the ground.[3] The cabanisi race has a strong preference for breeding in the dry season.[3]

Parasitic Nesting Interaction

The greater honeyguide (Indicator indicator) will occasionally parasitize the nest of the Scimitarbill. The exact frequency and effect that this relationship has on the species is not fully documented but there are several observations on clutch success rates different years.

In one case from June to July 2009 a pair raised three young in a nest box at Green park.  In another case, in June to July 2009 three young were raised by a pair of birds in a nest box at Greenwood Park Estate, Eburru, near Naivasha (0°40´S 36°12´E, 2150m). However, in another instance between October 2009 to July 2012,  a pair of birds laid a total of 33 eggs (11 clutches of 3) over 3 years. However, none of these eggs survived because the Greater Honeyguide (Indicator indicator) parasitized all the clutches. During the tree year period, no scimitarbills hatched, while 7 out of a total of 12 of the parasitic honeyguide eggs successfully fledged. On four cases out of eleven, the scimitarbills ejected all eggs from the nest. Later from August 2012-September 2014, four clutches (12 eggs total) were laid without any honeyguides, and all but one individual was successfully fledged.[10]

Gallery

References

  1. BirdLife International (2016). "Rhinopomastus minor". IUCN Red List of Threatened Species 2016: e.T22682710A92957434. doi:10.2305/IUCN.UK.2016-3.RLTS.T22682710A92957434.en. https://www.iucnredlist.org/species/22682710/92957434. Retrieved 12 November 2021. 
  2. 2.0 2.1 2.2 Bird, Jeremy P.; Martin, Robert; Akçakaya, H. Reşit; Gilroy, James; Burfield, Ian J.; Garnett, Stephen T.; Symes, Andy; Taylor, Joseph et al. (October 2020). "Generation lengths of the world's birds and their implications for extinction risk" (in en). Conservation Biology 34 (5): 1252–1261. doi:10.1111/cobi.13486. ISSN 0888-8892. PMID 32058610. https://conbio.onlinelibrary.wiley.com/doi/10.1111/cobi.13486. 
  3. 3.0 3.1 3.2 3.3 Reynolds, J. F. (1968). Abyssinian Scimitarbill Rhinopomastus minor cabanisi in Tanzania: A breeding record in a traditional beehive. Journal of East African Natural History, 117. https://hdl.handle.net/10520/AJA00128317_383
  4. 4.0 4.1 4.2 "Abyssinian Scimitarbill - eBird" (in en). https://ebird.org/species/absbil1. 
  5. Tobias, Joseph A.; Sheard, Catherine; Pigot, Alex L.; Devenish, Adam J. M.; Yang, Jingyi; Sayol, Ferran; Neate‐Clegg, Montague H. C.; Alioravainen, Nico et al. (March 2022). Coulson, Tim. ed. "AVONET: morphological, ecological and geographical data for all birds" (in en). Ecology Letters 25 (3): 581–597. doi:10.1111/ele.13898. ISSN 1461-023X. PMID 35199922. 
  6. 6.0 6.1 6.2 Lepage, D. (2004). Rhinopomastus minor (Abyssinian Scimitar-bill)—Avibase. AviBase. https://avibase.bsc-eoc.org/species.jsp?avibaseid=46847C50C05E10A6
  7. Oiseaux.net. "Systematic classification of species by Bucerotiformes - This order includes 4 families. 75 species listed." (in en). https://www.oiseaux.net/birds/famille.bucerotiformes.html. 
  8. Zimmerman, D. A., Turner, D. A., & Pearson, D. J. (1996). Birds of Kenya and Northern Tanzania. London: A & C Black. A & C Black.
  9. Birdlife International. (2023). Abyssinian Scimitarbill (Rhinopomastus minor)—BirdLife species factsheet. Data Zone. http://datazone.birdlife.org/species/factsheet/22682710
  10. Dangerfield, G., & Turner, D. A. (2016). The breeding of Abyssinian Scimitarbill Rhinopomastus minor and Red-throated Tit Parus fringillinus in nest boxes in the central Rift Valley of Kenya. Scopus: Journal of East African Ornithology, 36(2), 53–54.

Wikidata ☰ Q901570 entry