Nahoon Beach – storm surge event

Nature is proving the hypothesis that increased annual storm surges will be experienced along the South African coastline in years to come. The museum has recorded events over the past two decades and it has been noted that apart from big storm surges every few years (the last being in 2015) mini storm surges are increasing annually.

The biggest annual event occurred last night and a photographic record from Nahoon Beach illustrates just how large the impact was on the coastal primary dune adjacent to the internationally known beach.

A spring tide and days of windy coastal conditions (probably from storm centers south of the SA coast) produced heavy seas with large high energy waves displacing onto the shoreline. Areas where these waves were focused by a bay or promontory (such as Nahoon Point) received a battering and, in particular, the primary dune at Nahoon Beach.

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In recent times there has been no embryonic dune formation with concomitant stabilisation by pioneering dune plants and the effects of these waves erodes directly at the base of the primary dune. The caused massive dune slumping with tons of sand being eroded out to be deposited elsewhere.

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A hint of what was to come was noted on Monday 21st August 2017 when museum scientist Kevin Cole visited Nahoon Beach to document the beginning of an erosive coastal event. It was noted that concrete plinths used to stabilise a sewer connector pipeline had been exposed (for the first time in decades) indicating a low base erosion event along the beach.

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The dune slumping which had occurred along the primary dune at Nahoon Beach was not higher than 3m (as illustrated by the two ladies standing in the photo below taken on Monday 21st August 2017).

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The storm surge last night and this morning has further eroded the dune system, almost to the vegetation line (illustrated below- top photo Monday 21st August 2017, bottom photo Thursday 24th August 2017).

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Additional concrete plinth bases have also been exposed which run a line to the Nahoon River mouth. At the mouth on a very low tide the remains of the sewer pipe can be seen (in part) under the water crossing the river.

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As expected some other interesting specimens which have been buried will be found. A case in point is that a young visitor from KwaZulu-Natal found an animal tooth (which still has to be identified) at the Nahoon corner car park this morning.

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A site visit will be made to Nahoon tomorrow as more dune erosion is expected to take place at high tide later today and tomorrow morning.

Kevin Cole

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There is a dwarf in the tree ….

A few nights back an Eastern Cape Dwarf chameleon (Bradypodion ventrale) was spotted in an acacia tree in Beacon Bay, East London. Many years ago this species were quite common but they haven’t been seen regularly in recent times.

The Eastern Cape Dwarf chameleon is one of the larger of the fifteen currently recognised species of dwarf chameleons in South Africa (all of which are endemic to the country). The genus is widespread but essentially absent from the Kalahari and the Karoo.

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Eastern Cape Dwarf chameleon in Beacon Bay. Photo: Kevin Cole ELM

All dwarf chameleons are viviparous – an average of 5-15 babies are born alive and fully developed after a gestation period of about 3 months. These tiny (20mm) reptiles are fully equipped for survival and can feed on small insects.

Bradypodion ventrale illustrated above can be identified by a casque that is slightly swept back, a pale gular region and a dorsal crest composed of pronounced triangular tubercles. Two rows of larger tubercles are also noted on the flanks. It is a grey chameleon with a light central patch on the flanks. The enlarged tubercles my be yellow or green to orange-brown.

Chameleons are not found worldwide – restricted to Madagascar, Africa and some neigbouring islands such as the Comores, Mauritius, Seychelles and Zanzibar. There are about 150 – 160 species arranged into 9 genera.

Reference: Chameleons of southern Africa by Krystal Tolley and Marius Burger

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Controlled fire burn at the Beaconhurst School Nature Reserve today

Fires form part of a natural grassland ecosystem  and in areas which are protected such as the Beaconhurst School NR controlled burns are necessary to allow the rejuvenation of the grasses and the biome in general.

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Museum scientist Kevin Cole has been an honorary custodian of the reserve for the past decade and working with the principal of the school Mr Aubrey Norman it was agreed that a controlled burn should be undertaken. There was a lot of moribund grass and the combustibility of the veld in general was very high due to a persistent drought in recent months.

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The Beaconhurst School NR is an important, near pristine natural habitat in the suburb of Beacon Bay with a number of habitat types such as acacia (thorn tree) thickets, a small wetland, riparian forest (a valley of bush which joins up with the Qinira River) and the various grass types.

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Considerations for a burn which took place today included the wind speed and direction (westerly wind at 5 knots gusting to 7 knots), the anticipation of rain later in the day, preparations of  fire breaks and staff to control any fire flares (in the fire breaks which may run away into areas not included in the proposed burn footprint) and consultations with the BCMM Fire Department and the SA Police Service.

Before the fire was started Kevin spent 1.5 hours moving in transects above the riparian forest to encourage any animal specimens off the ear-marked burn footprint into the forest below. Blue duiker and bushbuck which live in the reserve were not seen in the area to be burnt. A look-out was kept for snake species and other reptiles and any such creatures were relocated to safe areas. The most difficult species to locate in thick grass are molluscs (snails) and smaller rodents.

An initial fire was started adjacent to a fire break with the wind from behind – as this flared up and raced in the intended direction Kevin moved around and started a back-burn. The process was repeated successfully until the area was burnt. There was a small break away fire which jumped the fire-break and happily the BCMM fire truck arrived timeously with enthusiastic staff to settle matters with a good dose of water.

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Kevin (EL Museum) and Andile (BCMM Fire) share a lighter moment after a smokey task at the reserve

The reserve is now ready to receive some good rains a present a flush of green in the coming months!

Beaconhurst School Chief Groundsman Stan and his staff are wholeheartedly thanked along with the principal Mr Norman for  successfully contributing to biodiversity conservation in the area.

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Risso’s dolphin stranding at Queensbury Bay, East London

Mr Alan Harris of Glen Stewart contacted the museum about a cetacean stranding on the rocks at Queensbury Bay. The animal was identified by museum scientist Kevin Cole as a Risso’s dolphin (Grampus griseus)- the largest dolphin not to be named a whale.

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Alan Harris with the Risso’s dolphin at Queensbury Bay (north of East London)

The stranding was reported on the 21st July 2017 and it it presumed (judging by the condition of the animal) that the dolphin had been floating at sea for a day or two before being washed up at Queensbury Bay. A reasonable amount of the delicate thin skin on the head had blistered off and there were a few scratch marks from a rocky entry to the shoreline.

The juvenile dolphin measured 2.01 meters in length and showed no signs of any major physical trauma. A reasonable amount of information has been gathered about Risso’s dolphins from mass strandings in South Africa between 1983 and 1991.

Diagnostic features for the identification of the species include a blunt head (beakless), a prominently centrally-placed erect dorsal fin (in adults) and numerous pale scratches and scars on mature animals. The calf stranded here is still uniformly coloured with a distinctive V-shaped crease from the blowhole to the tip of the rostrum.

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Risso’s dolphin – note the distinctive V-shaped crease in front of the bulbous head

The photo above also illustrates a whitish-grey anchor shaped mark on the chest connected by a thin mid-ventral streak with an irregular lozenge-shaped mark extending from the umbilical region to the anus. This marking persists into adulthood with the species.

Risso’s dolphins do not have teeth in the upper jaw. Erupted teeth have only been found in the lower jaw from dolphins in our waters – confined to the very front of the jaw (erupting at a body length of 1.88m). Between 2 and 6 pairs have been recorded in the species and in old animals the teeth become worn down often falling out resulting in an individual with no teeth at all.

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No teeth will be visible in the juvenile of the species as illustrated here for the stranded Risso’s dolphin at Queensbury Bay

Risso’s dolphins occur worldwide in tropical and temperate seas and can reach speeds of up to 28 km/h (normal travelling speeds are about 5.5 km/h or less). They mostly feed on squid and octopus.

Four mass strandings of the species have been recorded in South Africa – May 1983 (4 males and 4 females). April 1989 (10 males and 11 females), February 1990 (1 male and 6 females) and August 1991 (9 males and 2 females).

This is the second Risso’s dolphin record for 2017. Sean Pike of Wavecrest reported a live 1.5 meter animal which has beached close to the Nxaxo River and was released close to Sandy Point later on the same day (21st February 2017).

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A neonate 1.5m Risso’s dolphin which stranded at Wavecrest (Wild Coast) 21st February 2017. Photo credit: Sean Pike

After the release there were no reported sightings of the animal again and it is hoped it survived.

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The Wavecrest Risso’s dolphin being transported to the release site at Sandy Point. Photo credit:  Sean Pike

Risso’s dolphins can reach a length of 3.5 meters in the South African waters with the front half of the animal noticeably bulkier than the body behind the dorsal fin (whale-like upfront and dolphin-like in the tail region). At birth the dolphins are brownish-grey and becomes whiter as it ages (the combination of gradually lightening pigmentation and the accumulation of scars).

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Museum scientist Kevin Cole with the Risso’s dolphin calf which was buried after blubber, skin and muscle samples were taken. It was deemed too bloated to do a necropsy.

References:

Whales and Dolphins of the Southern African Subregion by Peter. B Best

Whales, Dolphins and Seals. A field guide to the marine mammals of the world by Hadoram Shirihai and Brett Jarrett

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The eagle and the monkey, Chintsa Bay

Local coastal resident Doug Kunhardt was on his property earlier this month when a Crowned Eagle (Stephanoaetus coronatus) caught his attention. A closer inspection revealed that the eagle had killed a vervet monkey (Cercopithecus pygerythrus). Is is not uncommon for the Crowned Eagle to prey on monkeys and they have developed a reputation for taking monkeys  in their distribution from the tropical forests of Senegal southwards as far as George in the Western Cape.

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The Crowned Eagle at Chintsa which caught a vervet monkey. Photo Doug Kunhardt

These eagles are unobtrusive and sit and wait (as photographed above) for hours for animals to pass by. It is an aerial hunter from above and within the forest canopy. It uses its powerful talons (particularly large for its size) to paralyse and kill the animal after dropping down on it.

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The vervet monkey which had been killed. Photo Doug Kunhardt

Other animals which form the bulk of the diet include Blue Duiker (very common in our coastal dune forests), young bushbuck (the heaviest record being a 30 kg ram), moles, dassies, guineafowl, leguaans and moles.

Crowned Eagles need to surprise monkeys if they are to catch them. If the monkeys are alerted to the eagle there is no chance of a kill.

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Entrails after disembowelment are pulled aside after the kill. Photo Doug Kunhardt

Doug’s photographs clearly illustrate that the eagle started feeding on the right hind quarter after removing the entrails. Food supply is an important factor which will determine whether breeding takes place or not. This species mates for life and have a permanent nest in a large forest tree. The nest presents as a bulky platform of sticks and twigs placed in the fork of a tree. Breeding takes place between February and November. Favourite trees to nest in are the indigenous yellowwoods and the exotic eucalyptuses.

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The spine of the monkey is visible in the photograph. Photo Doug Kunhardt

A few hours into the kill and the monkey has almost been completely devoured, save for skeletal bits and the head (as documented above). Interesting is that the Crowned Eagle normally flies off after disemboweling the prey and in this instance it seems to have fed on the ground.

Museum scientist, Kevin Cole, thanks Doug Kunhardt for documenting this natural history event and for submitting his photos for the record.

References: The birds around us by Richard Liversidge

The complete book of southern African birds compiled by P.J. Ginn, W.G. McIlleron and P. le S. Milstein

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Strandloper Hiking Trail – 21st Birthday!

In 1996 the Strandloper Ecotourism Board (SETB) was registered as a non-profit organisation to develop and manage the Strandloper Hiking Trail.  It was also established to develop ecotourism initiatives along the coastal areas between Kei Mouth and Gonubie. The trail was originally informally promoted by the Wildlife Society of South Africa (now known as the Wildlife and Environment Society of SA – WESSA).

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WESSA booklet promoting the Strandloper Trail

A business plan tabled in 1994 by the then Eastern Province Ministry of Agriculture and Environmental Affairs entitled ‘Ecotourism and Environmental Awareness Centre at Cape Morgan Nature Reserve’ set the proposal in place to formalise the Strandloper Trail. The East London Coast Nature Reserve manager at the time, Div de Villiers, drove the process along with community members from Kei Mouth, Morgans Bay and Chintsa. In 1996 the University of Pretoria, under the hand of Paul Bewsher, tabled a ‘Strandloper Eco-Trail and Strategic Marketing and Management Plan’. This document assisted founder members of the SETB to get the project started.

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The trail has grown over the past 2 decades and is rated one of South Africa’s top coastal hikes. During the formative years the relevant provincial coastal conservation component of the province provided a lot of support under the hand of Robert Stegmann (East London Coast Nature Reserve manager) who took over from Div de Villiers. Four overnight facilities were provided for hikers (along the 57 km route from Kei Mouth to Gonubie), the first being at the refurbished pump-house at Cape Morgan (situated on the rocks below the lighthouse), the second was two thatched rondavels at Double Mouth, the third being refurbished rangers huts at Cape Henderson and the final stay at Beacon Valley (near Chintsa).

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Chintsa Bay beach walk – part of the Strandloper Hiking Trail

Over the years the accommodation changed with hikers staying at the base camp at Cape Morgan Nature Reserve (for the 1st night) after the pump-house was destroyed by a storm surge in 2008 and the Cape Henderson chalet (3rd night) burnt down in 2011 resulting in alternative accommodation at the back of the Haga-Haga Hotel.

The success of the trail is largely contributed to very dedicated staff – Trail manager Bryan Church and his wife Erica (Reservations Manager) and two coastal rangers from the Chintsa informal settlement, John Pakamile and Johnson Mila.

The SETB also has dedicated members with a passion for the trail – special mention is made of Dave Marias (an avid outdoor enthusiast and owner along with his wife Linda of the Shipwreck Hiking Trail near Kleinemonde). His commitment to the product has been admirable (representing a great contribution from the Border Hiking Club) and he has been ably supported by long standing and founder member Sean Price of Chinsta, Janna Cooper (an original WESSA member who promoted the trail before it was formalised), Velile Ndlumbini who owns his own tourism company Imonti Tours and Brechta Kopke and avid hiker representing the ‘Let’s Hike’ Club in East London. One of the late founder members and hotelier, Jeff Warren-Smith, also played an enormous role with his generosity of assisting the trail during lean financial times.

The first Chairperson of the SETB, Mr Fritz Nieberding, also made a huge contribution before his retirement. He spent many years on the Board as treasurer after handing over the chair to museum scientist Kevin Cole in 1998. Other role-players to be acknowledged are Pep Saunders, Barbara Harcombe, Janine Vorster, Leigh-Ann Kretzmann, Dave Wilson and Paul Cromhout (the present Managing Director of the Small Projects Foundation in East London).

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The wasp and the spider, Baysville

The strength and resilience of some of nature’s smaller creatures is well documented in a photographic and video record submitted by Johan Koekemoer of East London. Last year he witnessed a wasp carrying a paralysed spider for 14 meters to a nest across an incredible man-made and natural obstacle course. His story begins in the suburb of Baysville when he noticed the wasp attack a spider on a palette of bricks at a building site.

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The species of wasp belongs to the family Pompilidae (well represented in Africa) – recognised by their long hind legs, curled antennae and smoky wings.

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They are often seen moving along the ground at great speed, vibrating their wings and antennae as they search for spiders (only the female seeks out spiders). This wasp has caught a common rain spider (Palystes superciliosus) of the family Sparassidae. These spiders are  ground living and can grow to a size greater than 30 mm (illustrated above).

After paralysing the spider (sometimes stinging it in the front of the head – helping to paralyse the fangs) the wasp normally cleans itself before moving off with the prey item to her nest. In this instance the nest was beyond the wall (illustrated below) over which she had to drag the spider.

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The climb to the top of the wall was more 2.3 meters! This amazing feat was achieved with a dedicated pace by the wasp using an amazing climbing technique, combining back and front legs in a coordinated fashion to keep the climb steady.

The wasp still had to drag the spider across the top of the wall (250 mm) before descending on the other side.

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The climb down was another massive act of strength and perfect coordination again on the part of the wasp.

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After having negotiated the wall the journey to the nest was an equal challenge through rough grass for another 9 m! The nest site was under a trampoline set back and on the other side of the wall.

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Part of the route also included climbing over a cut tree stump …….. .

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After a 40 minute journey, well documented by Johan, the wasp reached the nest burrow underneath the trampoline illustrated below. In total the wasp dragged the spider for 14 meters from the kill zone to the nest!!

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The museum thanks Johan Koekemoer for this amazing story and we hope it encourages others to be vigilant of the ‘happenings’ around our feet in suburbia.

Kevin Cole ELM

Photo credits: Johan Koekemoer

Spider identification: Astri Leroy (Spider Club of South Africa)

References: Southern African Spiders – An Identification Guide by Martin R. Filmer

Spiders of southern Africa by Astri and John Leroy

African Insect Life by S. H. Skaife

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