Notes on Nature - lots of interesting stuff
Endemic Dune Lark
| The African Bullfrog | |
| Lake Guinas, the dive of the century | Rhinos - Back were they once lived |
| The Grants golden Mole | Whales at Walvis Bay |
The African Bullfrog
I think the Giant Bullfrog should get an award for freaking people out. For years you will find yourself driving through the dry and hostile bushveld in the northern Namibian sand and limestone formations. The ground so dry, dusty and hard it becomes a concern on how even the larger trees with deeper roots can survive.
Then it rains, huge areas are covered with water, roads are being closed and tourists are unhappy to find that all the animals have moved away…. All but one species. Suddenly the air is filled with a sound cowboys had to live with every day, like a herd of invisible cattle moving past… mooing and moaning. To find that the ground is literally covered with bullfrogs, giant blown up green and yellow monsters hopping and bopping, mating constantly, males nearly drowning females with their weight.
To see them feeding on everything, I literally mean anything nearly alive in these pools, is absolutely spectacular. So every time I drive through the bush…doing the "lets look for Ellies and lions" thing, I keep wondering when the real spectacle will start again, when the "dead" suddenly become "alive" again.
I found this great sheet on the bullfrog's identity, please have a look, this animal deserves more people knowing about. Check out its unique way of surviving
CLASS: Amphibia
ORDER: Anura
FAMILY: Ranidae
GENUS & SPECIES: Pyxicephalus adspersus
CLASSIFICATION:
Amphibia, Anura, Rana, Pyxis (Gr) = box + cephale (GR) = head; aspersus = scattered, sprinkled; Asper = rough, harsh.
RANGE:
Tropical Africa around temporary bodies of water and small lakes.
PHYSICAL DESCRIPTION:
Weight: may reach several pounds.
One of the largest living frogs, with a "Jabba the Hutt" look.
Coloration: Pea green, with a yellow shin and lighter Venter. Juveniles have stripes.
DIET:
Wild: Anything that is small enough to cram whole into the mouth. If it moves, try and eat it. Insects and other invertebrates plus reptiles, amphibians, birds and rodents are all on the menu.
BEHAVIOR:
Active during the rainy season, they burrow into the mud to spend the dry season (which may last two years) wrapped in a mucous cocoon that hardens as it dries. When the rain return, the seeping water soaks this cocoon, which softens and splits open. The frog wriggles out and promptly eats the cocoon. Its capacious appetite puts weight on quickly. It must get quite stout before it is time to go into the mud again.
They even inhabit watering holes frequented by elephants and other large mammals.
They spend a lot of the day burrowed in at least partially, for camouflage. They have been seen using the crocodile style of hunting. Lying with all but eyes submerged at the water's edge, they lunge out to take even sparrows, which they unceremoniously stuff into their mouths with their hands.
BREEDING & GROWTH:
At the beginning of the rainy season the breeding season starts. Hundreds of eggs are laid in the temporarily swollen pools. Tadpoles have many predators, including mammals, wading birds of all sorts and even adult frogs.
The tadpoles grow quickly and in a few weeks metamorphose into small striped froglets. The gamut of predators continues. Juvenile frogs lose their striping gradually and are fully mature in 1 ½ to 2 years.
The exact life span of an African bullfrog is not known, but they have been known to live more than 20 years.
Lake Guinas, the dive of the century
Those of you who have been to Namibia probably visited Lake Otjikoto. Not very far away, hidden amongst numerous Aloe and dense thickets, the Guinas Lake can be found. It can be described as a spectacular hole in the ground, a sinkhole- geologically speaking.
Lake Guinas is the site Trevor Hutton chose to break the world free diving record.
Trevor Hutton prepared for this moment all his live." I could swim underneath the surface before I could even swim above it" Trevor called. This was his moment. Years of training, breaking the African record in France, and finally preparing himself at Godwana followed him to Guinas. Patrick Musimu of Belgium held the present world free diving record at 65 m.
"On a free dive you don't want to let any air out… you want to get the whole atmosphere into your lungs. Your air is being compressed - by the time you reach 10m the air in your lungs is already halved from the pressure. So you can imagine, right down at 70m you've got no air. Your air is going into your bloodstream already"
A normal man has the capacity of 4 litres in his lungs, through years of training and controlled yoga exercises Trevor has more than doubled this by having a capacity of 9 litres.
It took a lot of preparation to get everything organized from equipment for safety divers, judges, commentators, doctor etc. Unfortunately Trevor got a flu a few days before his attempt and had to "sweat it out" at a nearby farmhouse. Japie Potgieter, a local farmer, even helped design a foot grip for Trevor, which allowed him to dive "upright", a much more comfortable way of descending.
The greatest danger facing divers is the "shallow water blackout". This usually happens on the last part of the ascent - five to ten metres from the surface. The diver runs out of oxygen, blacks out and might die without support. So the support team is absolutely invaluable and contribute a large part to the diver’s success. For even the most skilled divers, the shallow water blackout remains a problem never to be underestimated. If he blacks out, he will be disqualified.
After a noisy preparation a countdown of 20 minutes is given and total silence falls over the valley of this sapphire pool. Trevor arrives and one of the two judges, Sebastian Nagel from Switzerland (Int. Dive Association), the other judge, a camera waiting for him at the bottom plate of the measuring rope.
Trevor touches the marker and descents down the 26 deg. C. clear water.
Date: 13 May 2001
Trevor Hutton dives anew world record of 66 m in 11 seconds… a faultless dive.
Rhinos - Back were they once lived???
Always waiting for rain, some years it came, sometimes the west wind just swept over the endless plains of Nomtsas. Dust curling up in circles past numerous Acacias and "gabbabos" as the Namas call the trumpet thorn, past dark powdery lifeless patches. To cross a riverine always seemed like a bit of relieve, our eyes appreciative of the little green sweetthorn that stood strong against the drought. He seemed so amazed of the ability of some acacias providing the so-called "emergency food" for hundreds of antelope - nibbling at the sweet flowers and small pods. "They taste well, sort of sweet…even you can eat them".
The south is regarded a flat and boring space where some farmers once earned a lot of money with karakul sheep, but that is over now and tourists come to look at the dunes...and maybe the canyon. Who would expect one of the most successfully rhino projects in a place where farmers wife’s drive 4 hours to go shopping.
It all started with a small "wildcamp', not far from the farmhouse, just a few wildebeest, hartebeest, loads of springbok and the occasional kudu, but they are there anyway. The 80's knocked him down completely. Nobody wanted Karakul sheep, Brigitte Bardot judged us cruel and it didn’t rain, seven years of drought had Heino Voigts on his knees, driving his truck - transporting other people’s sheep and cattle to South Africa, his wife tried her luck as a teacher in Windhoek. Everything died…..the "wildcamp" an empty patch of fenced in red Sandstone - hills. The rains came back though and so did they, while many farmers had long moved to more urban areas Heino gave it his last shot and caused many a sleepless night for some bank managers.
"I always thought they were grey“, amazement and cameras clicking permanently, “they roll in red mud sometimes". We observed "Otjivasandu' for some time when suddenly hell broke loose on the jeep. I could hardly believe my eyes, the cutest little newborn calf stumbled to his snorting mother, and so small it could have been a warthog. "This is her second calf in three years time" for a short period I thought I never saw him this happy, explaining the tremendous speed little rhino calves grow and that a small hump on the nose indicates the future horn, its possible fate. Although everybody on the vehicle made no secret of their disappointment of Heino leaving the mother so soon, they understood that we were the visitors and should never overstay our welcome, "she needs peace now - time for her offspring".
The first rhinos arrived in Nomtsas 1996, although one cow "Winnie" died due to a miscarriage, the others gladly accepted the area their long forgotten ancestors once thrived. The project was introduced and financed by the Ministry of Environment and Tourism. Many exciting moments with vetenarian H.O. Reuter, Chopper pilot Attie Hoffman and many Wardens had the "land the fishriver runs through" and the kitchen staff of Heide Voigts up and running. Today Nomtsas can proudly show about 6% of Namibia’s black rhino population, and they are going strong….very strong. Heino created a 20 000 ha large game reserve in 1992, to accommodate his cattle he has to rent 2 additional farms, "the south is a dry place you know". To protect the rhinos radio transmitters have to be planted in the horns - collars don't work, so it is an expensive business and largely privately financed.
"Both neighbouring farms are on the market at the moment we could create a over 50 000 ha large sanctuary for our rhinos, there is space for more then 50 of them here - easy to look after and protect, nobody seems interested in opening up their purse" he mocks us on our way home. Many thoughts on how to make the world a better place are discussed while we have to hold on to our hats, even the herds of springbok trying their best to pass the jeep and the curious giraffe on a nebrownii - plain could not change the subject and many promises are made. When some of my guests guaranteed him some support …..He just smiled….and maybe hoped for the best. Obviously the critics always pull up their eyebrows when we speak of reintroduction "did they really live here"? Rolf Kirsten, a previous Karakul farmer on the farm Daweb, a mere 60 km away from Nomtsas, has the answer. His shepherds once brought him 2 small rhino horns from the "veld". This is over 25 years ago; unfortunately he donated the horns to the Windhoek Museum, rotting away in some dusty corner now. Many gruesome stories of hunting expeditions in southern Namibia tell of rhinos being hunted for whatever reason.
The Namibian Ministry of Environment and Tourism promotes the redistribution of wildlife in Namibia to return species to much of their historical range as possible. Very important is the restoration of the functual role of wildlife in local and national economies through varies forms of wildlife utilisation. Wildlife utilisation has all the potential to become a major growth industry and the indigenous wildlife has greater resilience against drought then domestic stock and could bring even greater economic returns then livestock. Everybody knows that the goat is one of Africa’s biggest enemies anyway.
1970 65 000 black rhinos roamed the savannahs of Africa, 1980 only 14 800 rhinos where counted, 1990 the number even dropped to 2000, 1996 only 1200 rhinos survived on the whole world, of which more than 600 live in Namibia.
Namibia has virtually the entire world population of the black rhino subspecies Diceros bicornis bicornis. This population needs to be enlarged to a number of 2000 rhinos to ensure long-term genetic viability.
The D.b.bicornis subspecies is the largest of all black rhino subspecies and it is well adapted to very arid circumstances, which probably saved its life on a great scale……a poacher rather taking home a sunburn with a great thirst then a horn under his arm.
The protection of "our“black rhino enjoys highest priority not only internationally, which often doesn't mean much, but also within the Namibian government. It is a great step taken to put these specially endangered guys into the hands of private farmers, the Namibian government, however criticised, should be greatly congratulated for their cooperation in this project. Namibia plays a very important part in the world’s biodiversity and clearly has a big responsibility maintaining it, a large part being to protect the rhinos effectively. To protect a rhino doesn't mean to guard it day and night, but to make it less assessable to poachers, allowing the animal to live a stress less and relaxed life, reproducing and making nature happy.
More than 130 of Namibia’s rhinos already occur outside conservation areas and doing really well. The Namibian government not only supported the rhino relocation project, they also financed all transportation, medical assistance and follow up safety and health measures. It is a big matter of trust.
In 1994 26 farms applied for rhino custodianship, taking responsibility for a few black rhino, only 4 farmers fulfilled all the requirements. The area had to be fenced in a proper and secure way, the area had to be at least 10 000 ha big, the management on the game farm had to coincide with the view of the Ministry of Environment and tourism. A special "boma" had to be build to accustom the pachyderms to the new environment and food source. Due to its requirements in stability and size, to build a boma like that takes one huge bite out of a bank account.
The year 2000 was a good one for Nomtsas; a new female "Sophie" was introduced. Upon arrival all horns are cut of ( this does not harm the animal), a short-term conservation goal is established with that...The horn will grow about 6 - 10 cm per year, depending on the rhinos age. To ensure genetic variability, mostly females will be translocated, since males react very aggressive with other rhinos when translocated.
2007 – All rhinos have been removed from Nomtsas. The once so successful breeding programme was discovered by a poacher. Hamman, as the poacher is called, killed and wounded two rhinos… and was released on bail, since there was no proof that the Rhino-horn in his possession could be linked to Nomtsas. Heino Voigts was terribly disappointed by this fact and lost all his trust in the local judicial system and government – Unfortunately the Namibian government had failed him and he saw no future in carrying on with this idealistic task.
Whales at Walvis Bay
The sighting of a Whale around our Namibian West coast became a very rare event over many years of ruthless poaching by nearly every nation represented in our oceans. My uncle, who used to go out and catch "snoek", would sometimes tell us of Orcas (Ocrinus orca), also called "killer whales", he spotted while deep in the blue. I also heard of an occasion where teachers would let their pupils hurry to the beach to hope for a sighting of a recent large visitor in the water, - apparently nobody knew even what kind of whale it was.
But times have changed and it seems that sightings of whales have become more frequent - could it be that we as humans actually did something right? It seems like it.
Please check out the pics of the Pygmy right whale (Caperea marginata) rescued at the Walfishbay Lagoon the other day, its amazing to realize these creatures actually exist. Tourists on one of the Mola Mola dolphin cruises spotted a Southern Right Whale (Eubalaena australis) just outside harbour…. The whale even posed for some pics by breaching numerous times... …spectacular. The pics will come, so check the space.
The Pygmy Right Whale seen on the pics in the gallery was saved after 10 men carried it back to the water. It swam away immediately and seemed fit to carry on with its life.
One thing is sure; my eyes are peeled for whales. I want to see these mammals come back to our waters.
The Grants golden Mole Eremitalpa grantii
Barry Lovegrove, The living deserts of southern Africa, 1993
Its range extends southward into the succulent karroo. Grants golden mole is a small eyeless insectivore, which weighs a mere 20 g. Since it can't live in burrows like other moles, the sand is too soft in the dunes; it swims through the sand, like dune dwelling lizards. Research at the Gobabeb Desert Ecological research unit concluded that the body temperature of moles is not constant at all. It always lies within half a degree of the sand temperature, varying between 19 and 38 deg., so shows all the trademarks of an ectotherm, but being a mammal, should be endothermic. The golden Mole is the thermal hitchhiker of the desert. Since it lives in direct contact and is always surrounded by sand, which conducts heat much better than air does, the boundary layer around the body is absent and it really gets difficult to fight surrounding temperatures. This would drain all energy out of the little mole in no time. The mole lives with this problem by simply surrendering to nature. The body temperature is allowed to decrease to a certain tolerance level, from where the body starts producing heat again. The metabolic rate slows down and the mole goes into a dormant state, never loosing control though. Synchrone with the earth’s light - dark cycle, this happens even though the mole has no eyes, the brain tells the body to warm up again, whereby certain fat cells produce heat (non - shivering thermo genesis). This will happen in perfect timing for the mole to become active again at foraging time. This is a very costly process; a lot of energy is wasted when warming up endothermally. Instead of relying on inner fat cells, the mole makes use of the surrounding sand temperature, choosing not always to make use of "non - shivering thermo genesis". This is a unlike feature of the mole, saving it a world of energy. Each day, when the sand warms the body up to 30 Deg. Celsius, it begins hunting for insects, termites especially. This mixture of endothermy and ectothermy saves the mole considerable energy each day.
