During February, 2019, we took a break from our usual forest routine and headed off to one of Cape Vidal’s beach cabins for a couple of days. For those who don’t know, this bush and beach destination is set within the St Lucia Marine Reserve and is surrounded by the wetlands and coastal forest of iSimangaliso Wetland Park.
As we unpacked our luggage, a couple of vervet monkeys arrived, heading towards a cabin across the road where two children ate fruit on the balcony. Glancing around quickly, one of them bent over the rail, dropping an orange onto the ground.
The monkeys retrieved it.
Emerging from within the cabin, a man glared at the monkeys and screamed, then grabbed a taser and pressed the button.
During the last year, our observations of a samango (Cercopithecus albogularis/mitis labiatus) and vervet (Chlorocebus pygerythrus pygerythrus) troop at one of our sites, has shown that the two troops have formed an alliance; predator protection appears to be enhanced as they forage together on occasion (although their diet requirements are different, they do sometimes enjoy the same food source, for example, Ficus Craterostoma in this case). Our findings echo those observed in the blue monkey.
The blue monkey (Cercopithecus mitis) that is found in Central and East Africa, ranging from the upper Congo River basin east to the East African Rift and south to northern Angola and Zambia are known to form alliances with other species which last for several hours at a time (Rudran, 1978). These associations allow the group to form coalitions against other groups, locate food sources and provides protection against predators. These alliances also the monkeys to cover large areas while foraging (source: https://animaldiversity.org/accounts/Cercopithecus_mitis/).
Not wanting to disturb the samango and vervet monkeys (Cercopithecus albogularis labiatus and Chlorocebus pygerythrus pygerythrus) crossing the paddock to reach the Forest Fig (Ficus craterostoma), we sat over fifty metres away with our cameras.
I slowly moved closer, set up the tripod and looked through the viewfinder. Almost instantly an adult male vervet perched in the highest tree began to warn the others, convincing me to move back again.
When observing this troop initially, their behaviour suggested they had seen the darker side of humans, causing them to be particularly fearful. This factor makes it difficult to get close enough for great photos.
A man herded two horses and two donkeys into the paddock which was now completely devoid of any monkey presence.
Both vervets and samangos headed across the open paddock towards the fig tree.
Differences between the vervet and samango:
Habitat: The vervet monkey inhabits savanna, riverine woodland, coastal forest mountains and is often seen on the edge of indigenous forest where their range may overlap with the range of samango monkeys. Although the Samango monkey is often described as South Africa’s only primate “found exclusively in forests”, sightings of them foraging on the ground are not rare.
There are considerable differences in the diet of samango monkeys and vervet monkeys and these two species have different habitat requirements. These differences are reflected in the gut anatomy which relates to diet (see below).
Silence saturated the air after Lizzie and I left Mbona Private Nature Reserve’s (http://mbona.co.za/) tranquil, indigenous forest where we’d spent a few hours deep in the forest watching samango monkeys.
Samango Monkeys have a harem social structure, that is a single dominant male (there may be two adult males in the group) lives with adult females and their offspring. The social core is formed by related females, who will also defend their territory. The samango displays sexual dimorphism; adult males weigh around 9.5 kg while adult females weigh about 4.5 kg. Females give birth during the onset of the warm, rainy season. A single young is born after a gestation period of 140 days. Young are carried by their mothers for two to three months, and are finally weaned around the age of nine months. In Samango troops, oestrus is unsynchronised.
A Day in the life of a Trail Camera – Video footage on one day, captured by one of our trail cameras in Dargle Valley, an area consisting of human-modified land and indigenous forest, shows a glimpse into the lives of the vervets, samangos and bushbuck that regularly use a path bordering a paddock and indigenous forest. What is particularly interesting is that the samango troop follow directly behind the vervets confirming our past observations that these two troops have a friendly and symbiotic alliance.
Observing Bushbuck (Tragelaphus scriptus) in the company of baboons and monkeys is a relatively common sight in South Africa. It’s thought they have a symbiotic relationship, one that assists both species to outwit a lurking predator or make food more accessible.
A bank bordering indigenous forest and a paddock has proved to be a feeding site of this samango troop in Dargle. In the video below, captured by one of our trail cameras, an adult female and three juveniles feed on yellow flowers: Senecio harveianus .