What animal am I? -> Vervet Monkey

Week 8 of our “What animal am I?” series .…

Clue 1: I am primarily herbivore, but sometimes turn into an omnivore -> Living mostly on wild fruits, flowers, leaves & seeds they sometimes also enjoy insects, eggs and small birds!

Clue 2: Tyndall effect -> The vervet monkey has vivid blue “family jewels” (scrotum) which pales when the animal falls in social rank. The colour is not caused by hormonal shifts (mating interests), it has to do with the scattering of light by the skin itself -> like the Tyndall effect. It is concluded that the blue-to-white colour variation is modulated by the degree of dermal hydration. They do chemistry without knowing it!

Clue 3: I am a trichromat -> Old world monkeys and apes mainly see as humans do – they are trichromats, so they pick up red, green & blue. In some cases it's not as good as what we humans see - but it's much better than cats and dogs. Scientists say that good colour vision helps animals find ripe fruit.

Did you know…

The vervet monkey, is an Old World monkey of the family Cercopithecidae (Cercopithecus means ‘long-tailed monkey’) native to Africa. It sports a black face surrounded by a white fringe with various shades of grey to the reddish-green fur on the body, with long arms, long legs and a long tail. A vervet monkey is about the size of a large pet cat. Monkeys are generally considered to be intelligent, especially the old world monkeys.  

VERVET MONKEY:

Lifespan: up to 12 years (up to 30years in captivity)

Speed: 45 km/h

Scientific name: Chlorocebus pygerythrus

Mass: 3.9 – 8kg (females are slightly smaller than males)

Body length: 420 – 600mm (females are slightly smaller than males; measured from the top of the head to the base of the tail)

Diet: The vervet monkey eats a primarily herbivorous diet, but sometimes turn into an omnivore. Living mostly on wild fruits, flowers, leaves & seeds they sometimes also enjoy insects, eggs and small birds!

Vervets have pouches in their mouths where they can store food to be eaten later. 

They are arboreal (living in trees) monkeys and use their long arms & tail to move quickly and safely through the trees in forests and wooded areas near rivers and streams.

Although they do venture down to the ground in search of both food and water, Vervet Monkeys rarely go further than 450 meters from the trees, which helps to protect them from predators. They are diurnal (day-active) animals spending the days foraging for food and then rest at night. They need to drink daily.

Seeing in colour: Old world monkeys and apes mainly see as humans do – they are trichromats, so they pick up red, green & blue. In some cases it's not as good as what we humans see - but it's much better than cats and dogs. Scientists say that good colour vision helps animals find ripe fruit.

Blue Family Jewells: The vervet monkey has vivid blue “family jewells” (scrotum) which pales when the animal falls in social rank. The colour is not caused by hormonal shifts (unlike the red bottoms of baboons and other primates in heat), it has to do with the scattering of light by the skin itself -> like the Tyndall effect. It is concluded that the blue-to-white colour variation is modulated by the degree of dermal hydration. They do chemistry without knowing it!

The Tyndall Effect is the effect of light scattering in colloidal dispersion, while showing no light in a true solution. ... Because a colloidal solution or substance (like fog) is made up of scattered particles (like dust and water in air), light cannot travel straight through.

A colloidal solution or substance (like fog) is made up of scattered particles (like dust and water in air), light cannot travel straight through. Rather, it collides with these micro-particles and scatters causing the effect of a visible light beam… or in the Vervet monkey -> Blue Family Jewells 😉

For a better explanation please follow this link: Theoretical Chemistry

Social behaviour: They have been noted for having human-like characteristics, such as hypertension & anxiety. Vervets live in close-knit social groups ranging from 10 to 70 individuals which are called troops, with males moving to neighbouring groups at the time of sexual maturity. Troop members spend social-bonding time grooming each other, taking dirt and bugs out of their fur.

Hierarchy: Within a troop, adult males form a dominance hierarchy that is established and maintained by threat, aggression, fighting abilities, allies and age. Facial expressions and body postures are used to communicate threats or aggressive behaviour. Access to prime food recourses is determined by the dominance hierarchy.

Female hierarchy is dependent on mothering and producing offspring. Newborns are highly regarded in the troop, with all members acknowledging them in a supportive manner. Females that rear a greater number of infants gain respect and sit at the top of the female hierarchy.

Babies: Females have one baby at a time, typically every year. Babies are born throughout the year but mostly between October and March. Allomothering is the process when another individual besides the mother cares for an infant, generally they are choose siblings or infants of high-ranking individuals.

Grandmothers and grandchildren share one-quarter of their genes, infants approach their grandmothers more often than unrelated members and prefer their grandmothers compared to other adult female kin, not including their own mothers.

Communication: Vervet monkeys have four confirmed predators: leopards, eagles, pythons, and baboons and warn each other about potential threats using loud distinct alarm screams. Monkey are very vocal in their hierarchy displays and mothers can recognize their offspring by a scream alone.

Relationship with humans: In spite of low predator populations in many areas, human development has encroached on wild territories, and this species is killed by electricity pylons, vehicles, dogs, pellet guns, poison, bullets and is trapped for traditional medicine, bush meat and for biomedical research.

The vervet monkey has a complex and fragile social system, and persecution of the monkeys is thought to have affected troop structures and diminishing numbers. Many people living in close proximity to vervet monkey colonies see them as pests as they steal their food, fortunately however there are heavy fines in some cities to discourage the killing of vervet monkeys.