Banded mongoose

Banded mongoose
Two mongoose take an afternoon nap. This highly social species is threatened by a novel tuberculosis pathogen.

Wednesday, 23 September 2015

Banded Mongoose Disease Ecology

Banded mongoose are highly social animals that spend each and every moment of their lives with their troop. Their group dynamics, activities and interactions are a key determinant in the success of the troop as a whole, particularly in terms of security, territory establishment, marking, and maintenance, feeding, and grooming.

In terms of the present study, though, these group dynamics are interesting for precisely the opposite reason. The novel strain of tuberculosis (M. mungi) identified by Dr Alexander and her team at Virginia Tech's Alexander Lab actually seems to be making use of the social interactions of banded mongoose troops in the Chobe region in order to spread.

This kind of "piggybacking" is not unique to banded mongoose or tuberculosis, and yet the the presence and prevalence of this disease does present Dr Alexander and her team with the opportunity not only to investigate the mechanisms behind the transmission of this specific infection in these populations, but also to make some broader observations as to the manner in which diseases like this one affect the viability of social animals.

By monitoring the social behaviors and interactions of troops along the Chobe riverfront, Dr Alexander and her co-investigators hope to gain an insight into the manner in which this strain of TB is transmitted. Social interactions are carefully monitored and recorded, numbers are monitored, and visibly infected individuals counted and observed.

Groups typically range between ten and thirty individuals, and one of the objectives of this study is to determine the point at which a group is no longer viable. This phenomenon, known as the allee effect, is the product of the relationship between individual fitness and group numbers or population density, and understanding the way this works in banded mongoose populations will potentially have much broader implications as it relates to other social species.

The group pictured here is one of  the troops that is currently being monitored. There are a number of visibly infected individuals in this troop, and yet group as a whole is large and apparently healthy. Their social interactions are plain for all to see as they forage, groom each other, and sleep in the sun together, all the while keeping a watchful eye out for predators and other threats. The infected individuals in this otherwise quite idyllic scene offer a stark reminder that all is not well here.