Africa's animal kingdom Matira Magazin

Strange partners

Dwarf mongooses are shy little carnivores living in semiarid hot areas of Eastern Africa. Their family groups are often accompanied by hornbills and that has a good reason. Birds and mongooses form a partnership which benefits both. See how.

Strange partners: Dwarf mongooses and hornbills

Reinhard Radkes column on African wildlife

Dwarf mongooses (Helogale parvula) are energetic little hunters of small creatures, living mainly in semiarid warm regions of East Africa. In the Maasai Mara they are found, too. They belong to the family Herpestidae (mongooses), which are by far the most numerous carnivores of the Serengeti ecosystem. Scientists guess, that in the Serengeti about 160 000 mongooses occur (three species). They feed on many an insect and their ecological impact is certainly very big. Their family units are often accompanied by hornbills and there is a good reason for that.

Zwergmangusten
A family unit of dwarf mongoose comes together at one of the marking posts in their territory. Secretions of their anal glands inform them about any mongoose passing by, their sex, age and status.
Markierende Zwergmangusten
Standing upside down a male leaves his markings at the “family advertising board”. Such marks should warn off all intruders, for family members, however, the smell is very attractive. All of them like to have that parfume at their body as a kind of clan membership ticket.

The small hunters live in family units of up to 20 animals, with only the dominant pair breeding. Every family unit has a territory of a couple of ha, which is furiously defended and marked with gland secretions. Dwarf mongooses have a big problem: They are hunted, too, particularly by numerous birds of prey. Younger males thus spend much of their time looking out for predators, thus reducing their own foraging budget.

Zwergmangusten
Dwarf mongoose live mainly in dry semideserts, often in very broken terrain (these in Samburu National Reserve). Young males are constantly on the watch, as many predators hunt the little mongooses. This costs time, which can’t be used for foraging.
Grauflügelhabicht
A pale chanting goshawk feeds on a small mammal it just caught. These birds are very dangerous predators of dwarf mongooses.

So, it is quite clever, to engage a good watchdog! In the semiarid thorn bush, basically all dwarf mongoose groups live with hornbills. These birds catch insects on the ground and that is much easier, when they follow the groups humming with activity, scratching, and digging most of their time. Many disturbed insects try to escape and are easy picking for the birds.

 

Rotschnabeltoko
A red-billed hornbill sifting the ground, looking for insects. These birds are very cautious to aerial predators and react on every move in the sky.
Toko und Mangusten
Von der Decken’s hornbill picks a tiny morsel, right away from the mongooses. All hornbills are extremely cautious with aerial predators and react on approaching birds of prey faster than the mongooses. Thus, the mongooses have a very effective watchdog!

The mongooses don’t mind such losses: The different hornbill species are all well adapted to spot any raptor flying by. Their alarm call sends the mongooses instantly down the next termite mound. These “bodyguards” are well worth some morsels and birds and carnivores have a true “win-win-deal”. In ecology, such relationships are called mutualism.

Toko und Manguste
Under the watchful eyes of a yellow-billed hornbill this young mongoose goes about its business. Though the mongooses must share some of their food, they enjoy a partnership which makes life very much easier for them.

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