The rockjumpers are medium-sized insectivorous or omnivorous
bird
Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...
s in the genus ''Chaetops'', which constitutes the entire family Chaetopidae. The two species, the
Cape rockjumper
The Cape rockjumper or rufous rockjumper (''Chaetops frenatus'') is a medium-sized insectivorous passerine bird endemic to the mountain Fynbos of southernmost South Africa.
Taxonomy
The Cape and Drakensberg rockjumpers were split into sepa ...
, ''Chaetops frenatus'', and the
Drakensberg rockjumper, ''Chaetops aurantius'', are endemic residents of southern
Africa
Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...
.
[del Hoyo, J.; Elliot, A. & Christie D. (editors). (2007). '']Handbook of the Birds of the World
The ''Handbook of the Birds of the World'' (HBW) is a multi-volume series produced by the Spanish publishing house Lynx Edicions in partnership with BirdLife International. It is the first handbook to cover every known living species of bird. T ...
. Volume 12: Picathartes to Tits and Chickadees.'' Lynx Edicions. The Cape rockjumper is a resident of the West Cape and south-west East Cape, and the orange-breasted (or Drakensberg) rockjumper is distributed in the
Lesotho Highlands
The Lesotho Highlands are formed by the Drakensberg and Maloti mountain ranges in the east and central parts of the country of Lesotho. Foothills form a divide between the lowlands and the highlands. Snow is common in the highlands in the winter ...
and areas surrounding them in
South Africa
South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...
. The two rockjumpers have been treated as separate species but differ in size and
plumage
Plumage ( "feather") is a layer of feathers that covers a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage differ between species and subspecies and may vary with age classes. Within species, ...
. The ranges do not overlap, but come close to doing so.
Taxonomy and systematics
Originally, these birds were placed in the
thrushes
The thrushes are a passerine bird family, Turdidae, with a worldwide distribution. The family was once much larger before biologists reclassified the former subfamily Saxicolinae, which includes the chats and European robins, as Old World flycat ...
, and they have also been placed with the
Old World warblers
Old World warblers are a large group of birds formerly grouped together in the bird family Sylviidae. The family held over 400 species in over 70 genera, and were the source of much taxonomic confusion. Two families were split out initially, the ci ...
and the
babblers, but recent DNA studies indicate these birds are actually members of a basal group of oscines within the infraorder
Passeri
A songbird is a bird belonging to the suborder Passeri of the perching birds (Passerine, Passeriformes). Another name that is sometimes seen as the scientific or vernacular name is Oscines, from Latin ''oscen'', "songbird". The Passeriformes co ...
along with their sister-family the
rockfowl
The picathartes, rockfowl, or bald crows are a small genus of two passerine bird species forming the family Picathartidae found in the rain-forests of tropical west and central Africa. They have unfeathered heads, and feed on insects and inverteb ...
(Picatharthidae),
Their latin names derive from descriptions of their appearance. "Frenatus" refers to the "bridled" or black-and-white head pattern, while "Aurantius" refers to the orange coloration.
Description
These are small birds with mostly black, white, and red
plumage
Plumage ( "feather") is a layer of feathers that covers a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage differ between species and subspecies and may vary with age classes. Within species, ...
. Both species have long, white-tipped black tails, black throats, broad white submoustachial lines and eyebrows,
rufous
Rufous () is a color that may be described as reddish-brown or brownish-red, as of rust or oxidised iron. The first recorded use of ''rufous'' as a color name in English was in 1782. However, the color is also recorded earlier in 1527 as a dia ...
or orange bellies and rumps, and grey and black patterned backs and wings. Females have a similar pattern to males, but duller.
The iris is red and the bills and legs are black. Their wings are very small and they do not fly very often. They spend most of their lives running and jumping among rocks and grass while hunting insects.
Behaviour and ecology
Diet and feeding
The rockjumpers feed in groups, foraging on the ground. The groups can number up to 6 birds (for Cape) and 12 birds (for Drakensberg), but the groups may also spread out quite widely during feeding.
[Collar, N., Robson, C. & Sharpe, C.J. (2017). Cape Rockjumper (Chaetops frenatus). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from http://www.hbw.com/node/59691 on 4 July 2017).][Collar, N. & Robson, C. (2017). Drakensberg Rockjumper (Chaetops aurantius). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from http://www.hbw.com/node/59692 on 4 July 2017).] Insects are the major part of the diet, although small vertebrates are reported to be taken by Cape rockjumpers.
A range of insects are taken, including caterpillars, moths, grasshoppers, beetles and flies. In addition to insects other prey include lizards and geckos, amphibians, scorpions, annelid worms and spiders.
Breeding
They are
monogamous
Monogamy ( ) is a form of Dyad (sociology), dyadic Intimate relationship, relationship in which an individual has only one Significant other, partner during their lifetime. Alternately, only one partner at any one time (Monogamy#Serial monogamy, ...
and pairs establish
territories
A territory is an area of land, sea, or space, particularly belonging or connected to a country, person, or animal.
In international politics, a territory is usually either the total area from which a state may extract power resources or an ...
which are defended year round. In the Cape rockjumper the territories vary in size from . Both species employ helpers, usually the young of previous broods, to aid the breeding pair in raising the young.
[Holmes R, Frauenknecht B, & M Du Plessis (2002) "Breeding System of the Cape Rockjumper, a South African Fynbos Endemic" ''Condor'' 104 (1): 188–192 ] Nests are built out of grass on the ground (in contrast to rockfowl, which build mud nests in colonies).
The clutch size is two eggs for the Cape rockjumper and two or three eggs for the Drakensberg rockjumper.
Both sexes
incubate the clutch for 19–21 days. Chicks fledge at 19–21 days, although they are fed by the parents and helpers for up to 4 weeks following fledge.
References
{{Taxonbar, from=Q10745345
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Higher-level bird taxa restricted to the Afrotropics