RiverWise 

Issue 12 ~ March 2019

The monthly newsletter of the Lower Breede River Conservancy Trust

The Cape Fox

Description:

Cape Foxes are a small species of fox, and the only true fox that has its natural habitat in South Africa. They have a body length between 45 and 61 cm, a tail length between 30 and 40 cm and they weigh between 3 and 6.5 kg. They are coloured silver grey on their back and yellow on their flanks and underside. Their long tail is bushy with a black tip and they have slender legs. It inhabits mainly open country, from open grassland plains with scattered thickets to arid to semi desert scrub, and also extending into fynbos.


Biology:

They are nocturnal and most active just before dawn or after dusk. You are most likely to spot them very early in the morning, or crossing the road at night. During the day, they typically shelter in underground burrows, holes, hollows, or dense thickets. They are active diggers that excavate their own burrows, although they generally modify an abandoned burrow of another species, such as the springhare, to their needs. They are solitary creatures, and although they form mated pairs, the males and females are often found alone, as they tend to forage separately. They are not especially territorial but will mark their territories with a pungent scent.


Although a normally silent fox, the Cape Fox is known to communicate with soft calls, whines or chirps. However, it will utter a loud bark when alarmed. When in an aggressive mood, the they are known to growl and spit at their attacker. To show its excitement, the fox lifts its tail, the height of the tail often indicating the measure of excitement.


Cape Foxes have a diet that comprises both plants and animals. They will prey on insects, eggs, rodents, reptiles, hares, birds and spiders, or they will scavenge on carrion. They will also eat fruit and berries if they are available.


Reproduction:

Typical of most canid species, Cape foxes mate for life. They are capable of breeding all year long, although they typically have offspring in the months from October to January. The female has a gestation period of 51 to 53 days and gives birth to a litter of one to six kits.

Reared underground in burrows, the cubs stay close to the den until they are about four months old. They are weaned around 6 to 8 weeks of age, but do not begin to forage until they are four months old. Kits usually become independent at five months of age, when they disperse (June or July).


They have a life expectancy of about six years, but can live for up to 10 years.


Conservation Status:

Predators of the Cape Fox include hawks, owls, caracal and cape mountain leopard around the lower Breede River area. They often succumb to diseases such as rabies and canine distemper, and in more recent times have started to become victims of traps set out for problem animals. A large number of Cape foxes are killed on the road by vehicles. Many are hunted and persecuted as vermin. Some may be mistaken for jackals and held responsible for livestock losses. About 2,500 individuals are killed yearly; this is about 16% of the total Cape fox population. Nonetheless, this fox is not regarded as a threatened species by the IUCN.


March water quality data

The salinity from Gov. Slip to Goudmyn averaged 36 PSU (practical salinity units) with a peak at Gov. Slip with 36.74 PSU. The salinity decreased from 23.68 PSU by Powerlines to 14.28 PSU at Whitehouse. Riverine to the pont at Malgas averaged 0.5 PSU. These salinity values were impacted by the high rainfall earlier in the month as the increased freshwater in the Breede River Estuary meant the seawater could not extend as far up the estuary as previous summer months.

Secchi depth which is used to determine the turbidity of the water showing a similar trend.

Water clarity decreased the further you go up the estuary. Gov. Slip, Breede River Lodge and Mudlark sites recorded the least turbid water as the Secchi disc was seen down to 2.4 meters (Gov. Slip and Mudlark) and 3.1 meters (Breede River Lodge). The water became increasingly turbid and by white house the Secchi depth was 0.2m. Due to the rainfall in early March, runoff from the catchment brought muddy water into the system. The lower sites are influenced by seawater which is why the water is clearer by Gov. Slip when compared to powerlines.

Many fish species that use estuaries such as Dusky Kob (Argyrosomus japonicus) and spotted grunter (Pomadasys commersonni) show a significant positive correlation between relative abundance and turbidity, while others such as Leervis (Lichia amia) and white Steenbras (Lithognathus lithognathus) show a negative correlation between turbidity and relative abundance.

As the rainy season approaches, the salinity will decrease further with more and more freshwater entering the system.

Site Name:Salinity (PSU)Temperature (⁰C)Turbidity (m)
Gov. Slip36.7420.972.4
Hotel36.6120.953.1
Mudlark36.4220.982.4
Goudmyn35.7621.091.3
Karoolskraal30.0819.190.8
Powerlines23.6821.750.5
13km from RM20.6121.910.4
White House14.2822.110.2
17km from RM10.8222.310.1
Bobbejaanskrans4.2422.540.1
Ronnies1.8722.740
Bush Pub0.8622.080
Kemp0.5722.080
Riverine0.5122.710
Blue Gums0.4820.720
Deprecia0.4622.730
33km from RM0.4522.760
35km from RM0.4422.860
Dave Taylor0.4522.950
39km from RM0.4522.950
Pont0.4522.940

March bird count

After a brief early morning drizzle, the LBRCT team went out onto the Breede Estuary to do March’s bird count. Due to summer coming to an end, fewer species were recorded (29) as many have returned to their breeding grounds in northern hemisphere. Three migrant species were still recorded, whimbrel, grey plover and barn swallows. The most abundant bird species were Egyptian Geese with 458 birds, followed by South African Shelducks (127 birds) and Yellow-billed Ducks (89 birds). Blacksmith lapwings were the fourth most abundant bird species with 52 birds.

Interesting birds included common moorhens and a sombre greenbul in the reeds near Bush Pub.

Species:Count:
African Fish Eagle1
Barn Swallow1
Black Oystercatcher3
Blacksmith Lapwing52
Cape Cormorant7
Cape Weaver1
Common moorhen1
Curlew Sandpiper1
Domestic Geese1
Egyptian Goose458
Grey Heron6
Grey Plover11
Hadeda Ibis9
Kelp Gull56
Little Egret8
Pied kingfisher1
Red Bishop15
Red-billed Teal4
Red-eyed dove2
Reed Cormorant9
Sacred Ibis42
Sombre greenbul1
South African Shelduck127
Spur-winged Goose55
Whimbrel3
White-breasted Cormorant1
White-fronted Plover8
Yellow canary1
Yellow-billed Duck89
Grand Total974

March marine debris

The litter found from Blokke to the tidal pool mainly consisted of fishing related litter with 41% of all litter comprising of fishing line. In total 48m of fishing line was picked up on this short stretch of beach. The other main litter that was recorded was small pieces of plastic and glass and this accounted for 10% of the litter. Plastic bottles, bags and packaging were also frequently picked up.

Gov. slip to Skuitbaai beach litter was dominated by small plastic pieces that are often overlooked and even though a beach might look clean, it has lots of plastic smaller than 1cm in size. This accounted for 29% of the litter picked up. Plastic items from small pieces through to grocery bags accounted for 42% of the litter on this stretch of beach. Cigarette butts are still a problem on many of the beaches in Witsand and accounted for 16% of the litter on this stretch of beach. We ask if smokers could not throw their butts of the ground and dispose of them in proper cigarette butt bins placed around Witsand beaches. The LBRCT is working on putting more up in the area.


Oysterbeds through to Groenpunt still has a problem with broken alcohol bottle pieces with 28% of the litter picked up small pieces of glass. According to municipal signage drinking from glass bottles is not allowed on Witsand beaches, but we all enjoy having sundowners on the beach. We just ask that everyone takes their bottles with them once they leave the beach. Broken glass on the beach is also a safety issue. Plastic bags (13%), particularly the bags that come with sardine boxes were the second most important litter recorded. This was followed by cooldrink bottles (8%) and food wrappers such a chip packets, chocolate wrappers (6%).

Witsand main beach litter was dominated by small plastic pieces (45%), followed by discarded fishing line (16%). Plastic bottle caps, particularly coke bottles, was the third most abundant litter and accounted for 9% of the litter. Plastic and foam packaging accounted for 7% of the litter picked up.

Items:Total:Percentage:
Cigarrette Butts51.53%
Bottle caps (plastic)247.36%
Bottle caps (metal)10.31%
Lids (plastic)30.92%
Forks, Knoves, spoons61.84%
Bevergae bottles (Plastic)10.31%
Other Platic bags10.31%
Other plastic10.31%
Cups and Plates (foam)10.31%
Rope113.37%
Cotton spool10.31%
Fishing beads10.31%
Other plastic/foam packaging3911.96%
Tobacco wrap20.61%
Toothbrush10.31%
Construction material10.31%
Cork10.31%
Glowstick10.31%
Nurdles133.99%
Polystyrene10.31%
Glass pieces20.61%
Plastic pieces20964.11%
Grand Total326100.00%

Thank you for reading

We hope you enjoyed this months’ issue. Should you have any feedback, questions, or matters you would like us to cover in a future issue, please do not hesitate to write to us at news@breede-river.org. 

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