Wilkinson's World

Archive for February, 2011

The Grey-backed camaroptera was previously known as the Grey-backed bleating warbler, a descriptive name for the bleating alarm call of this little bird, which is not  unlike the bleating of a lamb. Very vocal, with another loud, penetrating call that sounds like two stones being tapped together – kwit-kwit-kwit – little bird is probably more often heard than seen.

On our journey to the Skeleton Coast Park we stopped off at Cape Cross, 115km north of Swakopmund, to see a breeding colony of between 80 000 and 100 000 Cape fur seals (Arctocephalus pusillus pusillus). And what an amazing sight it was, with seals as far as the eye could see.  The Namibian Wildlife authorities have set up a boardwalk so that you can walk above and between the seals without disturbing them.  The area understandably smells dreadful, but it’s a small price to pay for such an amazing sight.

The fur seals (family Otariidae) are also known as ‘eared’  seals as they have external ears, which other true seals don’t have. There are three species of fur seals along the coast of Southern Africa.

These seals don’t migrate and are present at Cape Cross throughout the year.  The males spend very little time at the colony during the non-breeding season – they’re busy building up blubber and food reserves that sustain them for about six weeks while they establish a territory and gather up a harem of between 5 and 25 females when its time to mate.

Shortly after the male arrives, the females come ashore to give birth to a single pup, weighing about 5 – 7 kgs.   Within a week of the birth, the male mates with all the females in his harem and their fertilized ova remain dormant for about three months before the nine month gestation period begins.  The pups are born within a six week period between November and December and start to suckle during the first hour of birth.

After the mothers and babies have bonded, the mothers leave the pups to forage at sea, often for days at a time.  While the mothers are out gathering food, the pups congregate together.  Fortunately mothers recognize their baby’s cries otherwise they could never be reunited.

The pups suckle for about a year, but start eating solids, like fish and crustaceans, when they’re four to five months old.  They are born with thick black coats, which moult to an olive-grey colour after a few months.

The pups face a number of dangers as they are growing up and their mortality rate is estimated to be about 27% of the total born.  Black-backed jackals (Canis mesomelas) and Brown hyaenas (Hyaena brunnea) are their main predators.  They can also be crushed during a stampede, drowned or abandoned.  Culling is also a contentious issue and we know that it does take place at Cape Cross.  It is euphemistically termed as a “management programme” in their brochure.

The cold waters of the Atlantic Ocean provide rich pickings for the Cape fur seals, with pilchards,  masbankers,  squid, octopuses and other crustaceans being readily available for them to eat.  They eat on average about 8% of their body weight per day, which is rather a lot considering that the males weigh in at between 180 kg and 360 kg and the females at approximately 75 kgs.

If you’ve had enough of seals and are driven away by the smell, you can go and have a look at a replica of the cross erected by Diego Cao, the first European to set foot on the Namibian coast in 1486.  It is located adjacent to the seal colony and was placed in honour of John I of Portugal.

The Greater kestrel is, as one would expect from its name, the largest of the kestrels found in the southern African region, being some 37 cm in length. The sexes are alike in plumage, the females being slightly larger than the males. Overall, the plumage of the adults is pale rufous, the back, upper wings and sides are barred, streaked and spotted with black and the breast is streaked. The rump and the tail are grey, with black bars and the tail is tipped with white; the bill is blue-grey; the legs and feet are yellow and the eyes are pale yellow.

The Greater kestrel is fairly common in the semi-arid regions of southern Africa where it is found in open areas of grassland, savannah and semi desert, particularly those areas where the ground cover is low. It usually hunts from a perch such as a tree, telephone pole or exposed rock, feeding mainly on grasshoppers, termites and other invertebrates, but also taking small birds, mammals and reptiles. Like the other kestrels, the Greater kestrel is able to hover as it surveys the terrain below for possible prey. They are sometimes found at the site of a veld fire, catching insects and other small prey fleeing from the flames.

Greater kestrels are monogamous and will often nest in the old nests of crows or one of the other raptors, located on a telephone pole, in a tree or even on a man-made structure. The female lays a clutch of three or four eggs that hatch after an incubation period of approximately 23 days.
The species is usually silent but has a shrill, repeated call kwirr, kwirr.

The scientific binomial for the Greater kestrel is Falco rupicoloides; Falco from the Latin for a falcon, and rupicoloides from the Latin for like rupicolus (referring to Falco rupicolus, the Rock kestrel). Thus a falcon that looks like a Rock kestrel, which is pretty well spot on.

With most of Namibia awash with rains, and a camping trip long overdue, last week we decided to head off to the dry Skeleton Coast Park for a visit.  Our first night was spent at Buck’s Caravan Park at Henties Bay, which enabled us to set off very early the next morning for our day trip through the Park.
We had spent some time researching the area so that we would know what to look out for.  There are a number of trip reports on this section of the coast, some of which are not very flattering, labeling the area as “boring”.  Fortunately, we also read that one should stop often to examine the countryside, as the desert is alive with lichen and other plant and animal life.  This made our journey so much richer and we’re glad we were offered that advice.

The journey to the Skeleton Coast Park is interesting in itself, with the Cape Cross seal colony a major attraction along the way, as well as the lichen fields, the salt works and the spectacular scenery, but we will write about these in separate blogs.

Entry to the Skeleton Coast Park requires a permit, which we purchased in Windhoek beforehand.  The gates at the entrance to the Park were impressive, if somewhat forbidding with their skulls and crossbones, and added to the excitement of entering an area that has evoked feelings of fear and dread in the hearts of many a sailor who has been stranded on the beaches with little hope of surviving the harsh desert.  It has also spelled the ruin of many prospectors who considered the area to be rich in minerals.

The first thing that strikes you about the Skeleton Coast, apart from its incredible beauty, is its isolation.  It was comforting to know that the Park officials knew we were there, because we only saw one other car for the duration of our five hour visit.  Imagine having a whole park virtually to yourself in this day and age!

After passing over the Ugab River, with its windblown shrubs and Acacia trees, we made our way to our first stop, which was the wreck of the Atlantic Pride fishing vessel.  Not much remains of this hapless boat, but it sets the mood and shows that man is no match for the angry sea and the desert.

The landscape is timeless and gives one a feeling of being in a state of quiet meditation.  The scenery changes every couple of kilometers so one is constantly looking at different colours and textures, from gravel plains to sand dunes.  We stopped often to examine the lichen fields which add golden colours to the ground.  It was as if our Maker had used every little rock as a miniature artist’s palette and then discarded it to go on to create an even better landscape further along.

Next we came across a rusty old oil rig which once was the dream of hopeful prospectors.  Now it is prey to the salt air that has rusted it into delicate filigree patterns that add a beauty of their own in the desert.

We were excited to come across both a black-backed jackal and a Gemsbok in the desert,  wondering what they lived on in this inhospitable environment.  At Torra Bay, which is deserted for all but one month of the year when the fishermen are allowed to camp there, the lonely buildings were guarded by cormorants and crows, which lent a mournful air to the place with their loud cawing.

We exited the Park through the Springbokwasser Gate on the east and this drive is also through magnificent scenery of barchan dunes and grey-capped gravel mountains dotted with grazing springbok.  We stopped to look at the Welwitchia mirabilis plants that are abundant alongside the road and the poisonous Euphorbia damarana, which are quite different from the usual Euphorbia plants that are found elsewhere in the country.

It was an incredible day’s drive and at no point were we bored or tired of the scenery.  In fact we’d love to be able to spend a bit longer exploring further up north as we’re sure the Park has a lot more to offer than we could cram into a single day.

The Ashy tit is a small bird, the adults just 15 cm in length, and is not very common within its chosen range. To come across one as it hops through the dense foliage of a tree, seeking the odd morsel is therefore always a treat.  It is near-endemic to the southern Africa region (its range spills over into part of southern Angola), where is prefers the drier western side of the region, being found in the semi-arid acacia woodlands, especially those along dry watercourses. Indeed, its preference for areas in which the acacia predominates is reflected the name by which it was known previously, the Acacia grey tit.

An attractive little bird, the Ashy tit has a grey body, with a black cap reaching down to its eyes and a black bib, with a broad strip of white on its cheeks separating the two areas of black. Its eyes are dark brown, its bill black and legs and feet are grey. The males and females are similar in both plumage and size.

Usually found in pairs or small groups, the Ashy tit is often seen in mixed bird parties as it feeds, mainly eating insects such as beetles, ants and flies, as well as spiders, fruit and seeds.
The call of this little bird is a liquid tutututututu-tuwee-tuwee.

The Ashy tit is monogamous and often nests in natural tree cavities or in the old nests of woodpeckers and barbets. The female lays a clutch of three to six white eggs, that may be speckled with red, and that hatch after an incubation period of about 15 days.

The scientific binomial for the Ashy tit is Parus cinerascens; Parus from the Latin for a titmouse, and cinerascens from the Latin for ashen. Thus we have an ashen titmouse, which is as close to the English name as you can get. The name “Titmouse” seems to have persisted in North America for the birds in this general family, while the shorter “tit” seems to have become more common in the rest of the English speaking world.