September 2012

Thank you to everyone who has submitted articles, photos and comments for this edition. Please do keep sending all the sightings and information through, The Raptor is what YOU make it.
In line with current eco-trends and aiming for a 'greener' lifestyle this is an e-newsletter - it does not conform to traditional page sizes and is not designed to be printed.

In This Issue
Spring has Sprung! Many species are Flowering
Warthogs! An in-depth look at these creatures.
The Geology of Raptor's Outcrops A closer look at the rocks!
Snake Removal - by Phone! A Marbled Tree Snake lives to tell the tale.
Pesky Porcupine! The hazards of feeding.
Photo Gallery Great results from our photographers!
Mystery Bird Did you identify this species?
A Final Word Leadwood Tree - a poem by Mark Blair




Spring has Sprung!
It seems spring is upon us - the temperatures have risen, and despite the lack of rain the bush is starting to flower. Here are a few of the early species.
Knobthorn Star Chestnut Cotton Creeper
Knobthorn - Acacia nigrescens
Star Chestnut - Sterculia rogersii
Wild Cotton - Gossypium herbaceum



Warthogs - Derek Solomon, RV254
Warthogs are certainly the most common animal on the estate. They are successful because of their ability to access grass roots and underground rhizomes when suitable vegetation above the ground is no longer available. The name comes from the warts on the sides of the face that could be compared to the protective padding used by American footballers! These help to protect the eyes and jaws when fighting - with much of the action being head-to-head pushing contests or bashing the sides of the face with heavy blows. Warts are made up of dense connective tissue and boars have two obvious pairs whilst sows only have one on the sides of the face below the eye. Both sexes also have a less obvious pair of warts on the sides of the jaw that are usually covered by whitish whiskers.

warthog warthog
Male
Female

The two pairs of curved tusks or canines protruding from the mouth are probably the most obvious characteristic of the warthog. The lower pair, which are used for defence against predators, but not in ritualised fighting between males, are much shorter and become razor sharp by rubbing against the upper pair every time the mouth is opened and closed.

Of the 18 species of pigs currently recognised around the world, 6 species including the warthog occur in Africa. The other species range from Europe to Asia with the Eurasian Wild Pig having the widest distribution of all. There are two species of warthog, the Common Warthog distributed through much of Africa, and the Desert Warthog, which is restricted to Somalia, eastern Ethiopia and eastern Kenya including Tsavo National Park though
warthog skull
a long time ago it also occurred in parts of the Cape and adjacent KwaZulu-Natal.

desert hog The main obvious differences between the two species relate to the warts just below the eyes which are hook-shaped in the Desert Warthog and conical in the Common. Also the tips of the ears bend backwards in the Desert Warthog. Another not so obvious feature is the lack of upper incisors in the desert species.

Compared with other pigs, warthogs have significantly longer legs which enable them to run with a characteristic springy trot. I am sure everyone has observed how fast a warthog can run, breaking immediately into a rapid trot as soon as they are disturbed. If necessary they can keep this up for a kilometre or more and have been recorded running at a speed of 55kph. The downside of this means that the head with its short neck is held well above the ground.

This could have created a feeding problem but the warthog has got around it by kneeling down to feed and easily moves along on its carpal joints or wrists while grazing. What is most interesting is that the callosities on the wrists are already present on the embryo before it is born.

warthog leg warthog feeding

Because they are not covered in dense hair or a thick covering of subcutaneous fat, warthogs are very susceptible to cold and youngsters in particular often die when temperatures drop to 0C. They are therefore dependant on suitable holes in which to shelter at night, and the number of Aardvarks in an area can play an important role in the survival of warthogs by creating underground refuges. When chased by a predator they dash for a burrow and, apart from very young piglets, enter backwards.

Wallowing in mud plays an important role in their lives particularly during the hot summer months as a form of temperature control. It also helps to protect them against biting flies.

While grasses form the most important part of their diet, fruits including marulas, figs and exotics such as mangoes are also eaten. Other food sources include bark, fungi, earthworms, scorpions and centipedes, birdís eggs and even small birds on occasion. They have also been recorded feeding on carrion particularly in the dry season and there are some camera trap photos of this behaviour taking place here on Raptors View. Grasses are cropped with the lips and underground rhizomes are dug up with the hard edge of the snout.

warthog wallow warthog snout

Warthogs have an amazing number of scent glands, particularly around the head. This includes lip glands and a pre-orbital gland below the eye that are used to mark the sides of trees, around burrows, wallows and other parts of their home range. The salivary glands and pre-orbital secretions are also used to mark other hogs.

The sparse body hair which is found mainly over the neck and shoulders can be erected under stress. The white bristles on the sides of the face of many individuals form distinct side whiskers that are particularly obvious in juveniles.

Warthogs often groom each other by rubbing or nibbling the skin and hair on the underparts in particular using the incisors. Individuals may lie down and roll over to expose the belly as an invitation to allogrooming.

warthog warthog




The Geology of the Rock Outcrops at Raptor's View - David Spencer, RV276
Scattered across Raptorís View are a number of conspicuous rocky outcrops standing as much as 4 to 5 metres above the surrounding terrain, as seen here.

These represent the surface expressions of geological features known as dykes. They are rarely wider than 10 metres, but extend vertically down into the earth for a great depth and run across the landscape in a North East direction for up to 30 kilometres at a time.

These dykes are composed of a rock type known as dolerite which weathers and decomposes to form a dark red clay soil in contrast to the sandy soils that dominate this area.
rocky outcrop


minerals This is a colourful illustration of the individual minerals making up the rock, namely plagioclase feldspar (white and grey), clinopyroxene (brightly coloured crystals) and ilmenite (black).

The presence of these structures bears testament to dramatic geological upheavals in this part of the world. The most recent of which started around 150 million years ago was the splitting of the great southern continent of Gondwanaland into five landmasses, namely Africa, South America, India, Antarctica and Australia.


The geological processes leading up to this event resulted in weaknesses and fractures being created in the earthís crust through which molten rock from the mantle was injected. The dykes were most probably feeders to volcanic eruptions that covered large areas of Southern Africa in basalt lava. Most of this overlying lava has now been eroded away with the exception of the Drakensberg mountains stretching from the western KwaZulu-Natal border through Lesotho and including the northern section of the Eastern Cape.

From an ecological point of view rocky outcrops are important as they present suitable habitats offering shelter to numerous animals such as reptiles and smaller mammal species. They also provide sheltered environments for certain antelope species to hide their young during the first days of life, e.g. duiker and nyala. A suitable environment is also created for certain plants to gain footholds, such as Ficus abutilifolia (Large-leaved Rock Fig) and Pachypodium saundersii (Kudu Lily), as shown below.

Rock Fig Kudu Lily
Large-leaved Rock Fig
Kudu Lily



Snake Removal by Phone - Lee Gutteridge, RV164
snake

We recently had a little visitor at 164 Snake Eagle; one which I believe is seen from time to time in the area. Unfortunately I was away at the time in the Waterberg at my guide training school, but my wife Sarah was able to recount in detail what was happening on the other end of the phone!

It is of course, not everyoneís favourite thing to have a snake in the bedroom. Especially when -
a) your game ranger husband is away, and
b) it is hissing and striking in a most unfriendly manner, and
c) it looks unlike any other snake you have ever seen!

This was the scenario one evening in late August, when a snake, about 70cm long was making its way calmly across our bedroom floor. Sarah immediately called for back-up....MOM! Anyway, Mom arrived, along with a very sleepy Kellen, who had been fast asleep up till this point. Now there was a team, so Sarah began to organise people! One was sent for a grabstick, another for a camera, while she manned the phone with me on the other end for advice and kept an eye on the snake.

Now the snake, suddenly subject to more attention than it was accustomed to, became aggressive and the repeated attempts to grab the reptile failed as it moved around so much and raised the front of its body striking repeatedly! It eventually, as these things always seem to do, found its way under a large immovable piece of furniture. This snake though was not smart enough to stay there, and soon appeared again near a sliding door, until harassed, at which time it went under the furniture again towards the other door while various and dissimilar types of encouragement and advice were passed along from the phone participant, and the two enthusiastic spectators on the bed! Eventually Sarah had the poor guy cornered. Now it was time to try again with the grab stick...but the snake had another plan. This fellow, over 70cm long suddenly pulled a complete Harry Houdini move, and squeezed himself through the gap between the two halves of the locked sliding door, and escaped into the garden!

Sarah, now very relieved, ran around to the outside of the house and managed to capture an image of the animal before he left for calmer pastures. Another fun event in the bush, and I am sure one which many of you have had, or will have in the future. My daughter, Savannah was most unimpressed to hear about this the next day, as she had managed to sleep through all the excitement, as only a 5 year old can!

The interesting aspect is that a Marbled Tree Snake is an unusual species which spends its time under bark, in hollow logs or in thatched roofs by day, and comes out to eat geckos at night! It is apparently often found around dwellings because of the amount of geckos, but it is only very mildly venomous and has no effect on a human being. It is reddish brown in colour, with a mottled head, averages 60cm in length, and has fine white crossbars on the body. It will flatten its head, coil up and strike loosely and aggressively at you in self defence, but I repeat, will not hurt you. Please have a look at the image provided, so that you do not inadvertently kill this snake out of fear that it is a dangerous creature because of its amazing behaviour during a moment of self-defence!



Pesky Porcupine! The Hazards of Feeding on the Estate
porcupine The point was well made at the AGM (particularly about a porcupine named Popcorn as he has been fed this treat and now actively looks for it.) and has been reiterated in recent bulletins from the office about the dangers of feeding (and habituating) our wildlife. The Prestons, RV288, had first hand experience of this when they were harassed by a very determined porcupine at an evening braai!

This same topic inspired this great sketch by Petro de Jager, RV330.
petro



Photo Gallery
Flycatcher Grey Louries
This female Blue-mantled Crested-Flycatcher has been around our house for most of August now. It is known to be an occasional altitudinal winter migrant, coming down from the escarpment forests along river courses like the Sandspruit. Other altitudinal winter migrants currently around our house are Red-capped Robin-Chat and Sombre Greenbul. Other possibilities to look out for in winter are Cape Batis and Narina Trogon.
JoŽl Roerig, RV21
Lawrence Morgan, RV283, sent us this great photo of a group of Grey Go-away birds (formerly called Grey Louries) in the top of a tree. It is not unusual for large numbers to gather like this at a suitable food source, but we are not certain what this gathering was up to.

The Grey Go-away bird ranges from southern Africa through to Angola, Zambia , Zaire and Tanzania. In East Africa there are three other species, the Bare-faced and the White-bellied Go-away bird as well as the Eastern Grey Plantain-eater.
None of the latter three give a typical g'way call like our bird and that of the Plaintain-eater has been described as a series of loud nasal notes that build up into a maniacal laughter (Field Guide to the Birds of East Africa).

giraffe giraffe
This giraffe stopped by to quench his thirst from our pool. He distracted me from the task in hand - a burnt creme caramel was the result! Jackie Preston, RV288

dwarf mongoose water monitor
Dwarf Mongoose - Lawrence Morgan, RV283
Water Monitor - Lawrence Morgan, RV283

wild dog nyala
Lone Wild Dog spotted on Snake Eagle in mid July @ 07.00 - Simone Braun, RV255
We saw this same dog on August 11 @ 18.00. A female giraffe spotted it and gave chase - with enthusiasm & determination! - D&S Solomon, RV254
Two male Nyala giving their spectacular stiff legged threat display while lifting up the white crest along the back that helps them to look even more intimidating. Don Priest, RV165

banded mongoose dwarf mongoose
We had visitors for 'sundowners' last month, and were delighted with their company... these Banded Mongoose were right in front of our deck.
Tineke & Spike Van Schalkwijk, RV107
This little family of Dwarf Mongoose arrived en masse hoping for crumbs from our afternoon tea!
Jackie Preston, RV288 (photo taken at RV125)

snake owl
Stripe-bellied Sand Snake - Don Priest, RV165
Spotted Eagle Owl - Don Priest, RV165

doormouse civet
Woodland Doormouse @ 05.00 taken on our Bushnell camera trap. Ron & Geoff Strike, RV112
Civet @ 22.00 on the same camera.
Ron & Geoff Strike, RV112

bush walk
The pre-school children of Southern Cross Schools were enthralled by all the Marabou Storks at Osprey Dam.
Les Blandy, RV125



Mystery Bird
mystery bird
No takers for this mystery bird! Was it too difficult - or perhaps not the right topic for this newsletter? We haven't had much response to the mystery bird photos so are thinking we should discontinue it.
Let us have your thoughts.

It is a Yellow-breasted Apalis and like all small warblers, it is constantly on the move. If you know the call of this bird, listen carefully to it, as it is actually often a duet between the pair, though unlike the duet of the Black-collared Barbet, it is not well synchronised. The duet is regularly given when the two birds are not within sight of each other suggesting the purpose is to strengthen the pair-bond rather than announcing territory.
 
black line
A Final Word
Mark Blair, RV170
poem