Mutualism in the Dwarf Mongoose

An interesting characteristic of the dwarf mongoose's social organization is their reliance on mutualistic relationships as a component of their predator protection scheme and foraging behavior.

Mongooses actively seek out mutualistic relationships with a number of bird species including the hornbills, Tockus flavirostris, T. deckeni, and T. erythrorhynchus, the White-crowned Bush Shrike Eurocephalus anguitimens, the Drogo Dicrurus adsimilis and the Lilac-breasted Roller Coracius caudata. Before leaving the nest in the morning, the mongooses actually delay their foraging start until the birds appear if no birds are there when the group emerges from the mound and the birds wait for the mongooses in the morning until they emerge (Rasa, 1983). "The hornbills arrive and wait in the trees around the mound for up to three-quarters of an hour until the first mongoose emerges. The birds then wait another half hour for all the mongooses to finish their morning" rituals (grooming, defecating, and marking territories with scent) (Rasa, 1985). It has also been noted that the birds sometimes attempt to hurry the mongooses through this ritual, flying to the mound and walking down it. While the mongooses move through the grass, the hornbills and other birds follow behind on the ground and in the air.

From this relationship, the hornbills and other birds gain easy access to prey that is disturbed from the grass as the mongooses forage. The moving insects, lizards and other animals that the mongooses encounter but are unable to catch make easy prey for the hornbills (Rasa, 1985). For example, the hornbills are much more efficient at catching small mammals, such as mice, so when the mongoose encounters and flushes out a mouse but is unable to catch it, the hornbills are likely to catch it almost immediately upon sight (Rasa, 1985). Interestingly, the hornbills do not prey on juvenile mongooses which resemble mice and other small mammals.

For the mongooses, the advantage is in assistance in guarding from predators. When the hornbills are present, the mongooses alter the number of guards working based on the number of hornbills present, decreasing the guards with increasing numbers of hornbills (Rasa, 1983). Thus, the hornbills may function as substitute guards for the mongooses, flying rapidly straight up in the air upon sight of a predator (mutually dangerous predators and predators specifically dangerous to the mongoose) (Rasa, 1983).