Archive for September, 2010
The Bizarre Welwitschia
September 29th, 2010 | 
Author: 
Posted in In June 2009 the Daily Telegraph in the UK ran a competition in their gardening section to find the “World’s Ugliest Plant”. The competition was won by the Corpse flower (Amorphophallus titanum) (no surprise there!) and coming in in fourth position with 12% of the votes was the Tree Tumbo (Welwitschia mirabilis). For me there were two surprises in that result. Firstly, in Namibia I have never heard the Welwitschia referred to as a Tree Tumbo, although this is apparently quite common in Angola, and secondly, I really hadn’t thought of it as an “ugly” plant. Bizarre, perhaps. Weird, perhaps. Certainly fascinating. But not really ugly.
So, just what is a Welwitschia mirabilis? Well, the Welwitschia was discovered by the Austrian botanist Friedrich Welwitsch, in 1859 in the Namib Desert of southern Angola. Thomas Baines, the well known artist and traveller, seems to have been the first European to take note of the plants in what is now Namibia, finding his first example of the plant in the dry bed of the Swakop River in1861. Welwitsch sent the first material of Welwitschia to Kew Gardens in 1862, and it was eventually named in his honour. The species name mirabilis means extraordinary, marvellous or wonderful in Latin.
The Welwitschia is limited in distribution to a narrow strip of the Namib Desert, stretching about 1 000 km northwards from the Kuiseb River in central Namibia into southern Angola. They are seldom found more than 150 km from the coast, and their distribution coincides with the fog belt, on which they are heavily dependant for their survival.
This extraordinary plant produces only two leaves that continue to grow throughout the life of the plant, reaching a length of up to four metres. Over time these leaves become split along their lengths and as they lie around the plant in a seemingly disorganized jumble, the fact that there are only two leaves is often not obvious. Although the age of the plants is difficult to assess, they live a long time and some of the older examples are thought to be in the vicinity of 2,000 years old. The largest recorded plants are to be found in the Messum Crater and on the Welwitschia Plains in Namibia. Strangely, the largest plants are found in the drier southern part of the range, with the plants in the wetter north being significantly smaller.
Welwitschias are dioecious, which means that there are separate male and female plants, and fertilization takes place through the transfer of pollen from the male to the female by insects that are attracted to the plants. They are classified as gymnosperms, although they differ quite considerably from other gymnosperms and have been placed in their own family, and are perhaps the last survivors of the plants from the Jurassic period when gymnosperms were dominant amongst the world’s flora.
Welwitschias  are highly adapted to grow under the arid conditions of the Namib Desert in those areas receiving regular fog. Fog is formed along the west coast of southern Africa when the cold Benguela Current, making its way northwards along the coast, meets the hot air coming off the desert. The fog builds up during the night and dissipates by mid-morning. During this time, the fog condenses on the broad leaves of the Welwitschia and trickles downwards; thus each plant waters its own root system. In addition, the leaves are able to absorb some of the water directly, courtesy of the stomata located on the leaves. Rainfall along the stretch of coast favoured by the Welwitschia is very low and somewhat erratic, with no rain at all falling some years, and “good” years receiving up to 100 mm. The plants are equipped with very long taproots, reaching down up to 30 metres, to take maximum advantage of what little water is available.
These fascinating plants are featured on the coat-of-arms of the Republic of Namibia.
Tags: 
Bird of the week – Week 38 : Madagascar bee-eater
There is a population of Madagascar bee-eaters that arrives in the north-western corner of Namibia and neighbouring southern Angola around September each year to breed. These birds stay for just four or five months before taking off on their intra-African migration for the rest of the year. There is apparently a separate population that is resident along the south coast of Mozambique, but it is the migrant northern Namibian population that we were fortunate to see along the Cunene River, west of the Ruacana Falls.
These beautiful bee-eaters are fairly large as bee-eaters go, being about 30 cm in length. Their plumage is largely green (they are also known as Olive bee-eaters), but they have brown crowns, rufous throats and a white eyebrow. Their eyes are bright red, their bills black and their legs and feet brown or brownish pink. The have the elongated central rectrices that are common to many of the bee-eaters. The sexes are similar in plumage, but the males are slightly larger than the females and have slightly longer rectrices.
Madagascar bee-eaters are seldom found far from water, and they are quite gregarious, often being found in groups of up to 20 birds. They feed mainly by hawking insects from a perch, to which they usually return to feed on the prey, which consists of bees, wasps, termites and other flying insects.
They are monogamous and make a nest in a burrow, which can be up to two metres in length, in a vertical bank of a river or stream. They are colonial nesters, with colonies of up to 60 breeding pairs being the norm. The female lays a clutch of three or four white eggs.
The scientific binomial for the Madagascar bee-eater is Merops superciliosus; Merops being the Latin for a bee-eater and superciliosus from the Latin for an eyebrow. Thus a bee-eater with an eyebrow. Not very descriptive and rather boring. But what if superciliosus was derived from the English word “supercilious”? Then we would have a haughty bee-eater that behaved as though it was superior to all other bee-eaters. Much better.
All creatures great and small
My previous blog was about the spotted hyenas that we saw on a visit to the Kruger National Park. I also spoke about the majority of people wanting to see the Big 5. It never fails to astound us, when we’re in a game reserve, to see how much people actually miss because they’re only intent on seeing big game. I’m not knocking them really, because obviously some people go to game reserves for that very reason, but there are so many different little worlds in the Park that folks who are interested in all creatures, great and small, get to see in addition to the bigger animals.
One can always see when something interesting has been spotted, because a car will stop and then everyone coming (from either direction) will pull in to see what they are looking at. This can be very helpful, because not everyone’s eyes are equally sharp and we would often have missed an exciting sighting of an animal deep in the bush if they hadn’t spotted it first. We would have missed these slumbering lions, for example.
One gentleman was extremely helpful when we stopped next to him and he gave us detailed directions of where to find a pair of cheetahs a few kilometers away on a side road.
Often we’re watching a beautiful little lizard sunning itself on the road, or photographing a tiny bird, and it doesn’t take long before we have accumulated an entourage of cars befitting a royal cavalcade!
When they finally give up in disgust because they can’t see anything they pull up next to us and ask what we’re looking at. On hearing that it’s a bird, we get a wave of the hand and a look of frustration as they announce to everyone in their car that “it’s only a bird.”   Don’t they know that we’ve just got a shot of an incredibly beautiful orange-breasted bush-shrike?
We came across a sensible fellow birder who had a sign in his window saying: “Please pass we’re watching a bird.” We also saw two guys who were tree-spotting. How interesting – at least their subjects didn’t run away out of sight or fly off.
Some of our most remarkable game reserve moments have been when we’re quietly sitting at a waterhole having a cup of coffee. Some visitors drive up to the waterhole, see nothing and drive away. Literally seconds after they’ve left, in will come an animal or a bird that makes the whole trip worthwhile. (It’s probably also happened to us dozens of times; there simply isn’t time to sit for hours at each spot.)  This beautiful white-headed vulture was a case in point when it came in to land at a waterhole we were watching after everyone else had left. Minutes later it was joined by a juvenile so we had a double treat.
Rob always says that you have to be “out there” to have these incredible moments in nature, but being out there is often not enough. Added to that you have to look at the whole of nature and, most importantly, have endless patience, which any bird or animal photographer will tell you is the key element. Birds and animals seem to have a sixth sense about cameras – they will sit quite still for ages until you bring out a camera and then they’re off! Oh yes, we know all about patience…
Bird of the week – Week 37 : Dusky sunbird
One of the fairly common avian residents of the arid western parts of Southern Africa is a small sunbird, just about 11 cm in length, which is busily active even in the midday heat, often found at flowering aloes or other plants, either singly or in groups, moving restlessly from flower to flower. This is the Dusky sunbird.
During the breeding season the male is predominantly black, with an attractive metallic sheen, and a white belly. The female, as is common with sunbirds, is rather dull by comparison, with grayish-brown upper parts and white under parts. The male is slightly larger than the female and in both sexes the eyes are dark brown; the bill, legs and feet are black.
Classified as a “near-endemic” in the Southern African region, the Dusky sunbirds feed mainly on nectar and also on insects and spiders, which they may glean from leaves or flowers; take while in flight or pluck from spider webs while hovering briefly. They are known to move from area to area in response to the availability of food. The call is commonly a loud “TSK” followed by trill “trr, trr, trr” lasting about two seconds.
Dusky sunbirds are monogamous and they build an oval nest of grass, leaves and other plant material, which is often fastened to a branch with spider webs. The female lays two or three white eggs that are variably mottled with brown. The eggs hatch after an incubation period of approximately 13 days. They are sometimes parasitised  by the Klaas’s cuckoo.
The scientific name of the Dusky sunbird is Cinnyris fuscus; Cinnyris from the Greek meaning shining and fuscus from the Latin meaning dull or dusky. Thus a shining, dull bird, which sounds a little contradictory, really. On the other hand, the male is shiny and the female dull…
The Dusky sunbird has been featured on a Namibian postage stamp – an image can be viewed here.
Spotted Hyenas in Kruger National Park
A visit to the Kruger National Park in South Africa is such a rewarding experience for avid animal and bird lovers like ourselves. We have just returned from a holiday in that part of the world and have literally hundreds of photographs to add to our collection. Kruger is renowned for being home to the Big 5 – namely lions, elephants, buffalos, rhinos and leopards – and the challenge is to see all these in one day. No mean feat when leopard numbers are low (only about 1000 were recorded in 2008) and the Park covers 20 000 square kilometers – the size of Wales! Some folks have been going to the Park for years and still haven’t notched up the Big 5 in one day.
While it is thrilling to be able to see the Big 5, it is also great to come across animals that are not so common or, during the daytime, to see nocturnal animals that haven’t settled down to sleep off the night’s excesses. Imagine our delight when, at first light, we came across a pair of spotted hyenas lying by the roadside. We approached them very slowly, worried that they would scurry off into the bush, but they were very accommodating and remained exactly where we found them, enabling us to get some great photos of them.
Spotted hyenas (Crocuta crocuta) are carnivores and belong to the family Hyaenidae. They tend to have bad press as they are mostly seen as cowardly scavengers in competition for prey that lion and other predators bring down. However, they are skilled hunters in their own right and feed mainly on ungulates and weaker animals that are easy to catch.
They have strong stocky forequarters, whilst their hindquarters are shorter and sloped downwards, making it difficult for other animals to catch them from behind. Their ungainly shape can be seen in the photo below – this was the second sighting we had of a hyena. It had hidden the remains of a carcass in the water and had come back to retrieve its meal. Prey is usually eaten alive and hyenas have voracious appetites – consuming about 14,5 kgs of meat at each meal.
Our third sighting was also early in the morning, when we came across a mother hyena suckling two young cubs in a den next to the road. She seemed unconcerned by the human paparazzi that were clicking away at the scene before them.
The gestation period is about 110 days and cubs (usually two, but sometimes three) are born throughout the year. Hyenas rarely dig their own dens, preferring to use deserted warthog or jackal lairs. Males don’t take part in the rearing of the youngsters, thus hyenas are mainly found in matriarchal clans, often sharing their dens.
They may not be as exciting as the Big 5, but we enjoyed our encounters with these awkward-looking creatures and now know a lot more about them than we did before.
