(This article first appeared on
10000birds.com)
Africa
has more than its fair share of storks, with 8 of the world’s 19 species
gracing the continent. Furthermore we have another very special stork-like
bird, the regal Shoebill, previously known as the Whale-headed Stork but now
placed in its own family. Storks are typically viewed as wetland species and
whilst some storks are restricted to aquatic habitats, others are not. This
blogpost discusses and illustrates Africa’s
stork species, with Shoebill added as a bonus or honorary stork!
A Marabou Stork arriving at its
roost tree, Serengeti, Tanzania by Adam Riley
We’ll start off with the largest
and ugliest of them all (measuring up to 60in (152cm) in height, a weight of 20
lb (9 kg) and a wingspan of up to 12ft), the Marabou Stork. Its name comes from
Arabic, meaning a Dervish with supernatural powers. Like the Adjutants in Asia
and Jabiru of the Americas,
the Marabou is our bare-headed scavenging stork. It is predominantly a wetland
bird and most productive larger wetlands and lakes of Africa will support a
population of these large, hulking birds that hang around the shallows
searching for fish, waterbird nestlings and anything else remotely edible. If
there are human fishing activities then all the better – Marabous will gather
in numbers around fishermen’s docks and fish markets, in fact anywhere where
fish are cleaned and scraps disposed of, allowing these intelligent birds to
obtain a free meal.
Ethiopia’s
Rift Valley lakes such as Lake
Ziway and Awassa are
famous for the gangs of Marabous that hang around the fish markets and allow
close approach in the hope of a smelly handout. Rubbish dumps are another
favorite, and just like the most reliable stake-out for the endangered Greater
Adjutant is Guwahati’s stenching rubbish-dump in Assam,
India, so can Marabous be
found at many rubbish dumps in Africa, slowly
picking their way through the rotten mess looking for anything edible. As a
result they sometimes even nest in the trees lining the streets of some African
towns and villages. They don’t often move into big cities, however Uganda’s capital, Kampala is an unusual haven for Marabous who
use its high-rise building as roosts. The story goes that they only moved into
the city during the time of the murderous Idi Amin who enjoyed throwing his
victims off tall buildings, and the corpses were left for the Marabous to
dismember.
Marabous have also learnt another
trick, and that is to follow vultures and scavenge off the remains of Lion and
other large predator kills. The Marabou’s enormous bill makes them the king of
the scavengers and even Hyenas are wary of approaching a Marabou’s dagger-like
mandibles. They have even been known to kill children who have been incautious
enough to approach too closely. As with most other storks, Marabous are not
vocal but a loud bill-rattling courtship ritual is often performed at nesting
colonies. Marabous occur throughout tropical and subtropical Africa from
Zululand in northern South Africa
right up to the arid Sahel region fringing the Sahara Desert,
avoiding the closed canopy rainforest zones of central and west Africa.
Marabous at Lake
Awassa fishmarket, Ethiopia by
Felicity Riley
A male Saddle-billed Stork (note
the dark eye and yellow wattles), St Lucia,
South Africa
by Adam Riley
Second largest, and at the other
end of the attractiveness scale, is the stunning Saddle-billed Stork. Only
slightly shorter, but more elegantly built than the Marabou, the Saddle-billed
also has a sister species in Asia, the
Black-necked Stork. Saddle-bills are more strictly restricted to wetland
environments where they are adept at catching their own fish with their
enormous upturned bills. They also prey on frogs and crabs. Sometimes they have
to protect their catches from piratic African Fish Eagles who swoop down as
soon as they that see a Saddle-bill has successfully caught a fish. They
display subtle sexual dimorphism, the male having dark eyes, dangling yellow
wattles and more black in the wing, whereas the female has bright yellow eyes,
no wattle and incredibly white wings that are absolutely striking in flight.
Their name is taken from the yellow “saddle” atop the bare red skin at the base
of their bill. The Saddle-billed Stork has a similar Africa-wide distribution
as the Marabou.
Yellow-billed Stork portrait
(note the pink flush indicating breeding status), Ngorongoro Crater, Tanzania
by Adam Riley
The Yellow-billed Stork has a
closely-related sister species in Asia known
as Painted Stork. It is also related to Wood Stork of the Americas and
Milky Stork of Asia. This is another wetland species that nests in sometimes
huge colonies atop trees bordering rivers and lakes. They are often found
roosting in small groups along the edges of lakes and riverine sandbars. Their
preferred feeding method is to stand in knee-deep water along the edge of
reeds, their bright yellow bill partially submerged and slightly open. They
then slowly move through the water, stamping their feet, in search of frogs,
small fish and other aquatic life that are quickly snapped up. During breeding
season, their white plumage turns a delicate pink color, a lovely sight indeed.
The Yellow-billed Stork also occurs throughout Africa
bar the far south and far north and they do partake in seasonal intra-African
movements. Its range also extends to nearby Madagascar.
Yellow-billed Stork in typical
feeding posture, Selous, Tanzania by Adam Riley
African Openbill in flight, Selous, Tanzania
by Adam Riley
The African Openbill is an all dark
stork named for a curious gap in its closed bill, formed by bizarrely shaped
upper and lower mandibles that have evolved to separate in the center. This gap
is used to maneuver this species’ favorite food, large aquatic snails, into a
position where they can be shucked from their shells. Further to the east,
Asian Openbill displays the same special feature but is mostly a white plumaged
bird. The African Openbill is one of Africa’s
smallest storks and rather slight in build. They nest in large colonies, often
mixed with numerous other waterbird species. The African Openbill also has a
similar Africa-wide distribution (barring most of South and North Africa) as
the previous four species and partakes long distance movements (usually
triggered by rainfall) through the continent and to Madagascar. In 2010, a remarkable
and previously unrecorded phenomenon occurred when thousands upon thousands of
African Openbills appeared from nowhere and spread throughout South Africa, even to the far southern tip of
the continent and remote Karoo semi-desert
regions where they had never been recorded before. Many hung around until they
died weeks, months and sometimes even a few years later, and the reasons for
this irruption and the birds’ source remains a mystery.
An African Openbill with its
favorite prey, an Apple Snail, Selous Tanzania (note the Yellow-billed
Storks in the background) by Adam Riley
A Woolly-necked Stork sunning
itself (note the woolly texture of the neck feathers) by Adam Riley
The Woolly-necked Stork also has
an interesting story of range expansion in South Africa. When I first started
birding 25 years ago and asked what the rarest bird in my province was, the
answer received was the Woolly-necked Stork, with just 3 or 4 breeding pairs in
the big game reserves of Zululand. During the
intervening years it has spread right down to the far south of the province as
well as inland, with hundreds of breeding pairs now in KwaZulu-Natal province. And at the same
time, Woolly-necked Storks have modified their behavior to survive even in
urban gardens where they scrounge for dog food on back porches! Further to the
north, they occur throughout Africa south of the Sahara and unlike the previous
species, their range stretches onwards through Asia,
as far east as The Phillipines. A dark bird with a white belly and neck, its
shoulders show iridescent gloss in sunlight and its neck appears fluffy, hence
its name.
Abdim’s Stork in flight, Tanzania by
Jonathan Rossouw
Abdim’s or White-bellied Stork is
the world’s smallest stork species and shows the most regular migration of the
storks we have so far discussed, moving with the rainfronts through Africa. It
appears in southern Africa only during the
Austral summer months, usually in large flocks that seek out locust and flying
termite eruptions. Once the drier winter months approach they move northwards
into East and West Africa where they are
particularly attracted by bushfires. It is quite a sight to experience hundreds
of Abdim’s Stork dropping out of the skies from seemingly thin air, to gorge on
burnt or fleeing insects and rodents. This stork is named in honor of Bey
El-Arnaut Abdim, a 19th century Turkish Governor of Wadi Halfa in Sudan.
A large flock of resting Abdim’s
Storks along the Nile, Uganda
by Adam Riley
A White Stork in its favored
short grass habitat, Sani Pass,
Lesotho by Adam
Riley
The White Stork is the most
strictly migrant of all our storks. It breeds on chimneys, roofs, buildings and
trees throughout Europe, parts of Asia and even North
Africa. In the northern winter, the bulk of the European and North
African population migrate down into Africa, as far as South Africa, where
large numbers frequent fields where they hunt for insects and rodents. They are
also attracted by fires and can gather in thousands. An aberrant small
population has decided that it’s far too much of an effort to migrate all that
way back north to breed, and have since 1933 started breeding just north of Cape Town. Satellite
tracking has shown that these individuals migrate northwards through South and
into East Africa during the winter months.
This southern breeding behavior is also undertaken by European Bee-eater and no
doubt the genetic isolation of these local breeders will eventually lead to the
evolution of new species of stork and bee-eater over time – just as many other
species have evolved in a similar way, for example Forest and Mountain
Buzzards, which evolved from Steppe Buzzards that stopped migrating and bred in
Africa. The elegant White Stork is the species that fable has decided is the
deliverer of human babies, a belief that dates back to ancient northern
European folklore.
An ancient White Stork nest at Ourzazate, Morocco
by Adam Riley
A pair of Black Storks with a
subadult bird by Adam Riley
Our final true African stork in
Black Stork, another species shared with Europe and Asia.
In Africa we have both Palearctic migratory and resident African populations;
however the breeding population of this species in Africa is far larger and
more widespread than the few dozen White Storks that breed in the Cape. Black Storks prefer to build massive stick nests on
cliffs (although tree nests seem to be the norm in Europe).
They are more aquatic than the closely related White Stork and spend the bulk
of their time foraging on the edges of rivers, mostly in search of frogs. In
winter, inland local breeding birds are often found at coastal locations where
they forage along estuaries and lakes.
Black Stork in flight, Sululta Plains, Ethiopia by Adam Riley
A subadult Shoebill, Murchison Falls, Uganda by Jonathan Rossouw
And now to our honorary stork,
the Shoebill. This colossal bird is now placed in its own family
Balaenicipitidae and it forms an ancient link between storks and pelicans.
Previously known as the Whale-headed Stork, its scientific name of Balaeniceps
rex translates as “King Whalehead”, in reference to its giant whale or
shoe-shaped head and bill. A massive gray bird with a staring yellow eye, its
broad bill sports a vicious hooked tip used for catching its favorite prey of
lungfish, catfish and watersnakes. The Shoebill spends its time absolutely
motionless on the edge of papyrus swamps, suddenly dropping face-first into the
water to grasp a fish. In the heat of the day they often soar high into the
sky, not something that one would expect of this bird! The Shoebill’s center of
distribution are the Sudd Swamps along the Nile in South Sudan, with smaller
numbers occurring into southwestern Ethiopia, Uganda, western Tanzania, Rwanda,
Burundi, Congo (DRC) with an isolated southern population in the Bengwuelu
Swamps of north-eastern Zambia. It should sensibly occur in the vast Okavango
Swamps of Botswana,
but all records from this region have been discarded. Due to disturbance by
fishermen, habitat destruction and nest robbing for zoos and bird collections,
the Shoebill is now classified as vulnerable.
Shoebill portrait, note the
massive hook on the end of its bill, Uganda by Adam Riley
Storks are truly magnificent and fascinating birds and the Shoebill is one of the worlds most unusual and sought-after species, Africa is truly blessed to have such a superb collection of these large birds.
