Written by Sophie Barrett
The aptly named dwarf mongoose is the smallest carnivore in southern Africa, pipped to the post in North Africa by the common weasel. Despite their diminutive stature, they are a fascinating species with a range of intriguing habits and adaptations to their name.
A dwarf mongoose (Helogale parvula) weighs on average between 210-350g with a maximum shoulder height of about 7.5cm, a total length of 35-40cm with 14-20cm of that consisting of tail! They are one of the two social species of mongoose, living in family groups of between two and 21 individuals. Collectively these family groups are known as a business and if you have ever had the chance to observe them you will agree they always seem to be pretty busy!
Dwarf mongooses are very sensitive to the cold and tend to live in termite mounds. They are territorial and mark the interior of the mound with secretions from cheek and anal glands. Interestingly, it has been observed that the dwarf mongoose, on the interior of the mound, only marks the northern part. It is not absolutely clear why this might be but it is suspected that it is due to movement of the sun.
Of course here in the Southern hemisphere the north side of the termite mound will receive the most sun throughout the day. It is thought the heat emphasises the effectiveness of the scent marking meaning that the scent from the north side permeates the whole mound. They will also mark territorial boundaries and have permanent latrines close to their sleeping dens that serve as scent marks and are used for several weeks at a time.
Within a business of dwarf mongoose you will have a dominant male and a dominant female, accompanied by their offspring and various immigrants. It is the immigrants that stand the best chance of assuming a dominant position at a later stage. Typically the dominant position is held for a couple of years at a time (about a third of their average lifespan of six years).
The successor of a dominant female is decided not by fighting but by an intense grooming competition. Two high ranking females will groom and lick each other, soaking each other in saliva, until one eventually gives up, the longest competition recorded took four days! The mongoose with the greatest endurance will be the new dominant female. Typically the males will fight to determine dominance with groups of males teaming up to oust dominant males of another group in order to replace them.
Dwarf mongooses have an advanced vocabulary which is put to good use by their sentry system. They have a host of natural enemies including slender mongooses, snakes, black-backed jackals, and birds of prey. As a result, whenever the business is outside of the den a sentry will be on duty looking out for predators. They have cheeps that signal that it is safe to leave the den and have different alarms to indicate a predator on the ground and one in the sky.
As an additional precaution dwarf mongooses never stray further from a bolt hole than the alarm of a sentry will carry. Whilst dwarf mongooses are out of a den you will often hear them chattering to one another. Typically they make a communication ‘peep’ every three seconds or so.
It is quite common to see dwarf mongooses in the presence of insect-eating birds like hornbills, drongos, and lilac-breasted rollers. The birds catch insects that have been disturbed by the foraging of the mongooses and the mongooses benefit as the birds act as an additional sentry system. In particular, hornbills have been observed sounding alarms in the presence of dwarf mongooses for predators that hold no danger for the bird but only for the mongoose.
Where this relationship is formed you will often see the same individual hornbill continually associating with the business of mongooses. Each morning the hornbill will show up at the den where the dwarf mongooses have spent the night, if the group are not yet awake the bird will call down to wake them up and wait whilst they all emerge before they head off to forage together.
Interestingly if the hornbill fails to show up one morning the mongooses have been noted to be agitated and restless, delaying their departure as long as they can and even sending individuals back to the den to check for the missing bird.
Dwarf mongoose will attack and kill snakes, relying on their agility (they can jump as high as 90cm) and thick coats to prevent snakebites. The whole business will mob a snake until it is exhausted and then the dominant female will kill it with a bite behind the head. Snakes are the only prey that is shared amongst the group.
We are lucky to observe these busy mammals around Bushwise campus on a regularly basis. Their constant banter with each other is fascinating and they are not still for very long.
There is a Bushman’s tale which could reveal why this is:
Once, before the times that you or I can recall, the dwarf mongoose and the secretary birds were great friends. They were walking through the bush together when they came across a large snake. Snake was a cunning fellow and asked mongoose to travel with him for he had a great secret he wished to share. With the sun beating down secretary bird had become very hot and so told mongoose that she would head to a waterhole to bathe and drink. Snake and mongoose continued their wanderings until they came across a great nest of twigs upon the ground.
Now sly snake knew that this was the nest of secretary bird but he did not tell this to mongoose. Instead snake asked mongoose if he had ever tasted egg. Mongoose shook his head and snake swiftly broke open and egg and encouraged mongoose to try it. Mongoose tucked in and quickly decided that egg was one of the most delicious things he had eaten. Snake and mongoose proceeded to eat all of the eggs from the nest. They were just polishing off the last egg when secretary bird appeared. Snake started to shout that her friend mongoose had eaten all of her eggs having tricked her into going to drink. And whilst secretary bird was sad that her friend had betrayed her she could see that snake had also eaten her eggs. Mongoose was distraught and explained to his friend how the snake had tricked him. Mongoose and secretary bird set aside their differences to turn on deceitful snake and killed him.
Secretary bird has never forgotten the lesson she learned, now she builds her nests atop thick, thorny trees to protect her eggs. She has not forgiven snake and will kill and eat him where she finds him, stamping on snakes with her long legs and horny scaled feet.
Mongoose too remembers the lesson he learned, where he finds them he kills snakes, by striking faster than lightning and being more agile than even the speediest snake, and eats them. However, he cannot forget the taste of the delicious eggs and whenever he finds them he will sneak into the nest and feed on them still.