Time for another posting!
While driving up the Tshokwane-Satara Road, we entered the N'wanwitsontso Loop (S86), where we saw: 1 European Roller, 1 Tree Squirrel (Paraxerus Cepapi
) and 1 Serrated-Hinged Terrapin (Pelusios sinuatus
These are pictures of the Serrated-Hinged Terrapin. They are nice pictures, but the future still reserved for us the most incredible meeting with this species. But this would still take some days.
Concerning its conservation status, unfortunately this species has not yet been assessed for the IUCN Red List. You can check its distribution in the following source: http://www.iucn-tftsg.org/wp-content/up ... 1_2009.pdf
In fact, this is a paper bringing a lot of interesting information about the Serrated-Hinged Terrapin, which is the typical deep water terrapin found in African rivers and lakes. During the rainy season, this terrapin migrates overland and colonizes isolated pans and waterholes. We did not know at the time, but we only saw them so easily in KNP because it was summer, the rainy season. This migration has to do with nesting, which takes place at the beginning of the rainy season.
In this same source we find the information that this species is not considered threatened. It was assessed as Lower Risk/Least Concern by the IUCN Tortoise and Freshwater Turtle Specialist Group in 1996. This information is not shown in the Red List because it needs updating. Anyway, it is very common in suitable habitats, as we could see later in the trip. An exception for this good conservation state is the case of populations in polluted rivers downstream from industrialized areas. Unfortunately, this is happening with the populations in KNP, whose entire aquatic ecosystem is at risk due to industrial pollution.
This turtle is included in the Pelomedusidae family. It is the largest species in the genus Pelusios
, with its carapace measuring up to 55cm. Females are larger than males.
A curiosity about it is that we can often find it basking not only on logs, rocks or mudbanks, but also on the backs of sleeping hippos. Its diet consists of water snails, aquatic insects, crabs, frogs, tadpoles, and fishes. In KNP, they were observed scavenging from the carcasses of animals predated by crocodiles and, also, taking ticks from buffalos. They also scavenge for bird nestlings that fall out of weavers nests overhanging the water. Occasionally, they eat floating fruits.
This species has several interesting defense strategies. Its hinged plastron protects the head and forelimbs when they are withdrawn (as it is typical of turtles and tortoises). Besides, this terrapin exudes or ejects a foul smelling secretion when threatened, for instance, when someone handles it, and is capable of using its sharp claws and horny jaws to bite.
After coming back to the Tshokwane-Satara Road, we reached Kumana Dam, where a rich diversity waited for us: 10 Waterbucks, 1 Comb (Knob-Billed) Duck (Sarkidiornis melanotos
), 1 Blacksmith Lapwing (Plover) (Vanellus armatus
), Impalas, 1 African Jacana (Actophilornis africanus
), 2 White-Faced Ducks (Dendrocygna viduata
), 1 Serrated-Hinged Terrapin, 1 Egyptian Goose (Alopochen aegyptiaca
) and 7 Burchell’s Zebras, including cubs.
Unfortunately, the dam is a bit far away from the road, so that good photographing was a challenge.
The Waterbucks were lying down the other side of the dam, with the Blacksmith Lapwing nearby them.
Here is a general view of the savannah behind the dam, with the waterbucks.
We were there watching the waterbucks and the plover, when this knob-billed duck came flying by…
He flew down the tree…
And landed just behind the waterbucks.
Here is a cropped image of the knob-billed duck. The original picture was good enough to get a nice cropped image.
This duck is widely distributed, being resident in Africa, South America, and Asia, as you can see here: http://maps.iucnredlist.org/map.html?id=100600412
In Africa, it is widespread below the Sahara, but absent from semi-arid and arid regions. This duck prefers pans, lakes or rivers surrounded by woodland, as Kumana Dam. Thus, its distribution basically follows the distribution of mature woodlands.
According to the IUCN Red List, its conservation status is Least Concern, but with a decreasing population trend. IUCN registers as threats to this species: hunting, logging and wood harvesting, natural systems modifications resulting from large dams, herbicides and pesticides.
Another source registers no significant threats, claiming that the population has in fact expanded as a result of the building of dams: http://www.biodiversityexplorer.org/bir ... anotos.htm
In this case, it is better to rely on the IUCN.
There is only one recording available in Xenocanto: http://www.xeno-canto.org/browse.php?sp ... illed+duck
The vulgar name of the species, either comb duck or knob-billed duck comes from the round knob that the male shows on the top of the bill. The word “comb” has a number of meanings related to “crest”. The knob is particularly prominent in the breeding season, from September to April. The animal we saw was a male and we were in the breeding season of the species.
During the breeding season, males defend territories, to which they often attract more than one female. However, males can only maintain harems of females in rich habitats. In poorer habitats, they tend to be monogamous. Sometimes, males are sequentially polygynous, i.e., forming a bond with one female at a time, moving on to the next one once she has laid the eggs.
Nests are built by females, usually a tree cavity, 4-12 m above the ground. It also nests on old Hamerkop nests, as many other birds, on rotten palm stumps, clumps of sedges or among rocks. Females compete for nest sites and can even fight each other for nests. Interestingly, ducklings have very sharp claws and can climb vertical wooden surfaces.
The longest lived knob-billed duck recorded lived for 21 years and 6 months.
The species moves extensively round Sub-Saharan Africa, as shown by data collected from ringed birds. Nearly 10% of recoveries were more than 2,000 km from where they were originally ringed. Many birds ringed in southern Africa have been recovered north of the equator. The longest distance traveled recorded for the species exceeds 3,500 Km.
It eats plant matter and a minor amount of aquatic insects when foraging in the water, and crop residues of wheat and groundnuts, seeds and fruits of grasses and herbs, and termite alates when foraging on land.
The picture is not great, but this was our only sighting of an African Jacana while in KNP. So, I cannot resist including it here.
African Jacanas are waders classified in the family Jacanidae. One can identify them by the long toes and long claws that enable them to walk on floating vegetation in shallow lakes, their preferred habitat. They can also be found in freshwater wetlands and margins of slow-flowing rivers with low vegetation. They are especially present in areas dominated by water-lilies (Nymphaea
), Willowherb (Ludwigia stolonifera
), pondweeds (Potomogeton
) and hornwarts (Ceratophyllium
They are a species of Jacanas, which are found worldwide within the tropical zone. The name “Jacana” comes from the Brazilian Portuguese “jaçanã”, the vulgar name of birds of the same group in Brazil. The Portuguese word, in turn, derives from the Tupi name of the bird, ñaha'nã, that is, from how the bird was called by the Indigenous people that contacted the Portuguese when they invaded the land that would become Brazil. “Jacana” in turn is the Latinized version of “jaçanã", introduced by Linneu.
In the IUCN Red List, the species is classified as Least Concern, with stable populations. Evidence that it is not threatened is that its distribution has remained largely unchanged for the past century.
African Jacanas are found basically in all Sub-Saharan Africa, breeding throughout this territory. Here is a map of its distribution: http://maps.iucnredlist.org/map.html?id=106003068
In southern Africa it is locally abundant in northern Botswana, the Caprivi Strip, Zimbabwe, Mozambique and eastern South Africa, while more scarce elsewhere in Namibia and South Africa. This explains why we did not see them much in KNP.
There is only one recording of its calls in xenocanto: http://www.xeno-canto.org/browse.php?sp ... an+Jacana+
That’s a noisy bird.
They feed on insects and other invertebrates they pick from the floating vegetation or water surface. When foraging, they walk or run with their large feet while plucking prey.
They are highly nomadic, often moving in search of new temporary wetlands.
Among the predators of chicks and eggs of the African Jacana, we find the Nile Monitor (Varanus niloticus
), the African Purple Swamphen (Porphyrio madagascariensis
), the Cape Clawless Otter (Aonyx capensis
) and the Hippos.
This is a polyandrous species, one female mating with multiple males in a sequential manner over the course of a breeding season. The male alone cares for the chicks. It has the ability to pick up and carry chicks underneath the wings, a remarkable adaptation for parental care. When they are small the male can carry up to four chicks under its wings.
It is a highly territorial bird, the males fighting each other for controlling the prime breeding territory, displaying and calling from a calling post made by pulling a few plant stems together.
Egg-laying season is year-round, peaking from November-March. The eggs are laid by the female in a nest that is a heap of aquatic plant stems, often just 2 cm above the water surface. Thus, the brood are vulnerable to changing water levels and the breeding pair may be found hastily assembling a new platform to move the young or eggs to a higher level.
The Serrated-Hinged Terrapin and the White-Faced Ducks were close to each other, allowing us to take this nice and tranquility-inspiring photo of two species I already wrote about.
Another nice sightings were the Zebras nearby Kumana Dam, with cubs, and mixed with Impalas. In the first picture, this looks like a caring mother.
The Zebras were resting from the hot day.
That’s it for today. I will come back soon with the second portion of the Tshokwane-Satara Road.
1 June 2013 - Twee Rivieren
2 June 2013 - Kieliekrankie
3-4 June 2013 - Kalahari Tented Camp
5 June 2013 - Twee Rivieren
6-8 June 2013 - Nossob
9 June 2013 - Gharagab
10 June 2013 - Grootkolk
11 June 2013 - Nossob
12 June 2013 - Twee Rivieren