Cape parrot

Cape parrot
At Benvie, Karkloof, KwaZulu-Natal, South Africa.
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Psittaciformes
Family: Psittacidae
Tribe: Psittacini
Genus: Poicephalus
Species: P. robustus
Binomial name
Poicephalus robustus
(Gmelin, 1788)
P. robustus range

The Cape parrot (Poicephalus robustus) or Levaillant's parrot is a large, temperate forest dwelling parrot of the genus Poicephalus endemic to South Africa. It was formerly grouped as a subspecies along with the savanna-dwelling brown-necked parrot (P. fuscicollis fuscicollis) and grey-headed parrot (P. f. suahelicus), but is now considered a distinct species.

Description

The Cape parrot is a short-tailed moderately large bird with a very large beak used to crack all sorts of hard nuts and fruit kernels, especially those of African yellowwood trees (Podocarpus spp.). This contrasts with the closely related savanna species (Poicephalus fuscicollis) which feeds on and a wide variety of tropical woodland trees such as marula, Commiphora spp. and Terminalia spp. These species are sexually dimorphic, with females typically sporting an orange frontal patch on the forehead. Juveniles also show a larger orange - pink patch on the forehead but lack the red on shoulders and legs of adults.[2] These plumage characteristics vary among individuals and among the three recognized forms.[3]

Taxonomy

There are conflicting classifications of this population due to the existence of three geographically separated but closely related forms that differ in habitat, size and plumage. The dominant view of the ornithological community, especially in Africa, considers these as two species, with the temperate, montane forest dwelling Cape parrot, P. robustus distinct from the savanna species, P. fuscicollis, including the brown-necked parrot, P. f. fuscicollis of West Africa and the grey-headed parrot, P. f. suahelicus of eastern and southern Africa. This view is reflected in the 2011 IOC World List (adopted by many, including Wikispecies, as the global standard[4]) along with recent reviews and field guides from Southern Africa.[5][6][7][8][9][10] These may in fact be three separate species[11] but this view needs substantiation through studies of plumage, ecology and genetic variation within and among the two forms of P. fuscicollis. The multiple species interpretations are supported by the lack of overlap in distribution between the three forms, by the distinct biomes and dietary preferences of the Cape parrot (P. robustus) and the other two forms (which occur in different types of tropical savanna) and by limited data on mitochondrial DNA differences among forms.[12][13] The Birdlife International taxonomic checklist of the world's birds[14] conflicts with these sources by considering all three forms as subspecies of a single species Poicephalus robustus. This disagreement impacts on the perceived global conservation status of these parrots.

More detailed genetic analysis of the three taxa published in 2015 confirmed the distinctness of brown-necked and cape parrots, showing that ancestors of the two had diverged between 2.13 and 2.67 million years ago—in the late Pliocene to early Pleistocene epoch. This period was a period of changes in climate, where grassland and forest were expanding and contracting, which led to isolation and eventually speciation of separate populations.[15]

The name Cape parrot only applies strictly to the form in South Africa. The name un-cape parrot has gained limited popularity as a general name for the two savanna forms (as "brown-necked", used by most sources, is an inaccurate description of the "grey-headed" form in the east African savanna).

Distribution and habitat

The Cape parrot is endemic to South Africa. It occurs in Afromontane forests at moderate altitudes in eastern South Africa from the coastal escarpment near sea-level to the midlands at around 1000m. These forests occur as a series of small patches around the south and east of South Africa and are dominated by yellowwood trees (Podocarpus latifolius, P. falcatus and P. henkelii). Cape parrots have a disjunct distribution with the largest population around in the Amathole mountains of the Eastern Cape Province and extending east, with several large gaps, through the Mthatha escarpment and Pondoland in the Eastern Cape and the southern midlands of KwaZulu-Natal Province to Karkloof, near Pietermaritzburg. A very small population, of around 30 individuals occurs over 600 km to the north in the Magoebaskloof area of Limpopo Province. Cape parrots are absent from large areas of afromontane forests such as those along the southern coast of South Africa, near Knysna, the higher altitude Afromontane forests in the Drakensberg mountains of KwaZulu-Natal, or the moderate-altitude forests of northern KwaZulu-Natal province and Swaziland, which separate the KwaZulu-Natal midlands and Limpopo escarpment populations.[16] All of these areas are within the dispersal range of the parrots and there are old records of Cape parrots from northern KwaZulu-Natal.

Aviculture

Over one hundred P. robustus parrots are kept as cage birds, most of which are wild-caught birds although they do breed reasonably well in captivity. To date there have not been any successful releases of captive birds and the survival of this species is dependent on habitat conservation to maintain wild populations. Trade and export of wild-caught Cape parrots from South Africa has been made illegal by the international CITES agreement (appendix list II) and by South African law. They are rare as pets, despite low-levels of ongoing illegal collection and trade. Those that are kept have demonstrated wonderful personalities, and a talking ability that rivals their larger cousin the African grey parrot. A small trade still persists in the related Grey-headed and brown-necked parrots.

Conservation status

The IUCN Redlist 3.1, which uses the Birdlife International checklist, lumps the common and widespread grey-headed parrot with Cape parrots and brown-necked parrots, each of which are more narrowly distributed and more threatened, leading to an assessment of least concern.[17] This contrasts with alternative assessments of the South African endemic P. robustus, as endangered[18] and possible threatened status of the brown-headed parrot of West Africa. There are only about 400 in the wild, and the Cape Parrot Project is trying to save them.

Hundreds of volunteers participate on the first weekend each May in the "Cape Parrot Big Birding Day" which is an annual count of the population throughout its distribution. The parrots are relatively easy to count at any forest patch due to their distinctive silhouettes, slow, 'rowing' flight and raucous calls. Counts are made in the evening as parrots arrive at roost patches and in the following morning as the parrots leave. A complete census of the population is difficult to achieve, however, as these forests are naturally fragmented and there are insufficient volunteers to count the more remote patches. There are also difficulties in achieving a precise count because the birds fly long distances for food and may be 'double-counted' at both feeding and roosting sites. Counts increased from about 500 specimens in May 2000 to over 1000 in recent years, although this may be largely explained by an increase in the particular sites that were counted. The parrots are particularly threatened by the fatal psittacine beak and feather disease virus (BFDV), and there have been suggestions that a diet heavy in yellowwood fruits greatly reduces the symptoms, although this has not been empirically investigated. Their habitat is being reduced by logging and modification of African yellowwood trees, in particular the loss of old trees and dead snags with suitable nesting hollows. The provision of nesting boxes has had some success and offers some hope for increasing the proportion of breeding individuals.

Wikimedia Commons has media related to Poicephalus robustus.

References

  1. ↑ BirdLife International (2016). "Poicephalus robustus". IUCN Red List of Threatened Species. IUCN. 2016: e.T22685284A93065899. Retrieved 2016-12-09.
  2. ↑ Downs, C.T. 2005. Cape Parrot Poicephalus robustus pp. 221-222 in Hockey, P.A.R., Dean, W.R.J. and Ryan, P.G. (eds) Roberts - Birds of Southern Africa, VIIth ed. The Trustees of the John Voelcker Book Fund, Cape Town.
  3. ↑ Symes, C.T. 2005. Grey-headed Parrot Poicephalus fuscicollis pp. 222-223 in Hockey, P.A.R., Dean, W.R.J. and Ryan, P.G. (eds) Roberts - Birds of Southern Africa, VIIth ed. The Trustees of the John Voelcker Book Fund, Cape Town.
  4. ↑ "Archived copy". Archived from the original on 22 May 2011. Retrieved 2011-05-05. [Accessed 5 May 2011]
  5. ↑ Gill, F and D Donsker (Eds). 2011. IOC World Bird Names (version 2.8). Available at http://www.worldbirdnames.org/ [Accessed 5 May 2011].
  6. ↑ Sinclair, I. and Ryan. P. 2010. Chamberlain's Birds of Africa South of the Sahara, 2nd Ed. Struik Nature, Cape Town
  7. ↑ Sinclair, I. and Ryan, P. 2009. Complete photographic field guide: Birds of Southern Africa. Struik Nature, Cape Town
  8. ↑ Chittenden, H. 2007. Robert's Bird Guide. A comprehensive field guide to over 950 bird species in southern Africa. The Trustees of the John Voelcker Book Fund, Cape Town.
  9. ↑ Hockey, P.A.R., Dean, W.R.J. and Ryan, P.G. (eds) 2005. Roberts - Birds of Southern Africa, VIIth ed. The Trustees of the John Voelcker Book Fund, Cape Town.
  10. ↑ Sinclair, I., Hockey, P., Arlott, N. and Hayman, P. 2005. The larger Illustrated guide to birds of southern Africa, 2nd Ed. Struik Publishers, Cape Town
  11. ↑ Sinclair, I. and Ryan. P. 2003. Chamberlain's Birds of Africa South of the Sahara. Struik Publishers, Cape Town
  12. ↑ Solms, L., Berruti, A., Perrin, M., Downs, C. and Bloomer, P. 2000. Phylogenetic relationships of the three subspecies of the Cape Parrot, Poicephalus robustus. 17th meeting of the South African Genetics Congress. June 2000. Pretoria
  13. ↑ Perrin, M.R. 2005. A review of the taxonomic status and biology of the Cape Parrot Poicephalus robustus, with reference to the Brown-headed Parrot P. fuscicollis fuscicollis and the Grey-headed Parrot P. f. suahelicus. Ostrich 76: 195-205
  14. ↑ Birdlife.org
  15. ↑ Coetzer WG, Downs CT, Perrin MR, Willows-Munro S (2015). "Molecular Systematics of the Cape Parrot (Poicephalus robustus): Implications for Taxonomy and Conservation". PLoS ONE. 10 (8): e0133376. PMC 4534405 Freely accessible. PMID 26267261. doi:10.1371/journal.pone.0133376.
  16. ↑ "Archived copy". Archived from the original on 5 October 2011. Retrieved 2011-05-05. [South African Bird Atlas Project 2; Accessed 5 May 2011]
  17. ↑ Iucnredlist.org
  18. ↑ "Archived copy". Archived from the original on 14 May 2011. Retrieved 2011-05-05. [Accessed 5 May 2011]
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