See classification of
birds
Origin of birds
Fossil evidence has provided abundant evidence that birds
evolved from within the theropod dinosaur clade Maniraptora. So the little
white-eyes flitting around in the trees of your garden are dinosaurs and quite
close relatives of the fearsome Velociraptor (also in the Maniraptora)
that is portrayed in
Jurassic
Park! The size difference between a white-eye and the largest dinosaurs
(the sauropods) is
not all that unbelievable when you consider the difference in size and appearance
between the
Blue whale and a mouse, both of which are
mammals.
Of
all the animals alive today, birds are unique in having feathers. However, it
gets a bit more complicated when you examine the fossil record because it
appears that feathers were present in quite a few groups within the Maniraptora
dinosaurs and it was from one of these groups that the birds emerged and
radiated.
It is usually stated that the ealiest known bird is
Archaeopteryx, which is known from about 10 fossils in 155-150 million year
old (Jurassic Period) rock strata in southern Germany. Archaeopteryx
clearly did have feathers similar to those of modern birds but it also had some
primitive theropod dinosaur characters such as teeth. Some define birds as only
the modern forms (the Neornithes). Others define birds as including modern birds
and Archaeopteryx. It is thought unlikely that Archaeopteryx is
the direct ancestor of modern birds but it is certainly closely related.

Archaeopteryx lithographica - cast of the 'Berlin specimen'.
[photo H. Robertson, Iziko] |
Bird diversity
Birdlife
International recognises 9990 species of birds (download checklist from
here; excludes fossil species, includes recently extinct species [e.g.
Dodo]) but it could be as high as 10105 species if you include those that
Birdlife International has currently under review. These latter species include a number recognised in the new Roberts (Hockey et al. 2005) such as
Forest
buzzard, Carp's tit, and
Karoo thrush. This list of
species under review also includes Yellow-billed kite (Milvus
aegyptius), which is not recognised in the the new Roberts, but which
probably is a separate species from the Black kite (Milvus migrans).
It is amazing for such a well-known group of organisms that there are still new
species of birds being described: See
Bird species new to science described in the 2000s (Wikipedia). Most of
these have been discovered in tropical regions of the world. In addition, there
are old established species that are being re-evaluated on the basis of new
genetic evidence, resulting in them being split into two or more species. In
southern Africa this splitting of old species has happened particularly in the
larks.
Roberts Birds of Southern Africa lists 951 species
from the southern African subregion (i.e. south of the Cunene and Zambezi
rivers), which amounts to 9.5% of the world total and 41% of the approximately
2300 species recorded from Africa. This is slightly more than the 925 species
recorded from the much large region of the USA and Canada and a little less than
the 1000 or so recorded species from the whole of Europe. However, it is
overshadowed by the impressive bird diversity in the Neotropics (South America).
It is within this region that the highest bird diversity of any country in the
World has been recorded, namely in Colombia where the bird list stands at 1895
species (see
List of birds of Colombia - Wikipedia). This is all the more impressive when
you consider that the land area of Columbia is 15% less than that of South
Africa (1038700 km2 vs 1219912 km2)!
So while southern Africa can't boast of having the highest
bird diversity in the world, it still does pretty well compared to some other
regions of the World. The bird list includes 98 endemic species
(i.e. only found in southern Africa), five breeding endemics (i.e. only known to
breed in southern Africa but non-breeding range extends out of the region) and
62 near-endemics (distribution extends only slightly out of southern Africa)
(Hockey et al. 2005). There are also two endemic families, namely the
sugarbirds and
rockjumpers.
Contributing to the diversity of birds in southern Africa
is the wide range of habitats that are available. These range from oceanic and
coastal marine through to freshwater pans and rivers, deserts, semi-deserts
(Nama Karoo and Succulent Karoo), fynbos, thicket, grassland, forest, savanna,
and woodland (which is an extreme form of savanna).
This site
This site presents a page on each of the species of birds
that have been recorded from southern Africa. Duncan Robertson has spent hours
finding, editing and inserting images of the different species and has also
contributed text for many pages. We are most grateful to the numerous bird
photographers that have generously allowed us to use their images. The
photographer is acknowledged below each photograph (except thumbnails) and there
is a link to his/her website or web page.
The coverage is still not complete. Most of the species are
illustrated by photographs but there are many pages still requiring text.
The information presented for each species is derived
mainly from the new Roberts Birds of Southern Africa (Hockey et al. 2005)
simply because it is the most authorative text available. We have focused
particularly on interactions with other organisms so that we can put each bird
species in its ecological context and link to taxa presented elsewhere in
Biodiversity Explorer that are predators, prey, parasites or fullfil some other
role such as plants that provide nest sites or nesting material.
Links
This introduction to birds does not go into too much detail
because there are some excellent resources elsewhere, some of which are listed
below:
-
Bird (Wikipedia).
A useful introduction to birds.
-
Origin of birds (Wikipedia).
-
Bird
Evolution (Wikipedia).
-
Bird
anatomy (Wikipedia).
-
Birdlife
International. "BirdLife International is a global Partnership of
conservation organisations that strives to conserve birds, their habitats
and global biodiversity, working with people towards sustainability in the
use of natural resources. BirdLife Partners operate in over one hundred
countries and territories worldwide." One of these partners is Birdlife
South Africa (see below).
-
Birdlife South Africa. The lead organisation in South Africa for
everyone interested in birds and their survival. There are about 8000
members in
40 branches and affiliates throughout South Africa.
-
Birdinfo.
Articles and news about birds, especially those in southern Africa. Articles
feature rare species and the biology and ecology of particular species -
very interesting reading with excellent photographs.
-
Bird
Families of the World. Really nice review of bird families of the world,
showing photographs plus bird sounds plus info. on life histories.
-
Cornel Laboratory of
Ornithology. Includes a huge sound and video archive that includes many
African bird species.
-
Fatbirder. A comprehensive site on birds and birding, including book and
web resources, information on bird watching equipment, and news on birds -
especially bird conservation.
-
Birding on
the net. Good place for links to bird
web sites.
Publications
- Hockey PAR, Dean WRJ and Ryan PG (eds) 2005. Roberts - Birds of
southern Africa, VIIth ed. The Trustees of the John Voelcker Bird Book
Fund, Cape Town.
|