Banded Mongoose Research

Life history evolution

 

One of our major projects is to understand the forces that shape patterns of fertility, growth, health and aging in mammals that live in close-knit family groups. Research on humans and laboratory mammals has shown that conditions experienced during early life can have a profound impact on health, behaviour and aging across the lifespan. For highly social animals, the quality of the early life environment depends to a large extent on how much care and attention offspring receive during development. Very little is known about these early life effects in wild mammals, particularly those that exhibit complex social behaviour. Banded mongooses are an ideal study species to explore these questions because multiple females give birth on the same day to a large litter that is then raised communally. Some pups receive lots of care and attention during early life, while their littermates (including siblings) have to fend for themselves from an early age. We are exploring the consequences of this variation in early life care for health, behaviour, reproductive success, and patterns of aging.

Examples of our current research into Life History Evolution include Marshall et al 2016 and Cant et al 2016.

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Senescence and aging

 

Why, in human and animal populations, do some individuals deteriorate with age much more rapidly than others? Most research on ageing has been conducted on laboratory organisms such as fruit flies, nematode worms, and rodents living in a sterile environment. New advances will require studies of wild animals to understand how aging occurs in organisms exposed to natural parasites, pathogens and predators. We are using cutting-edge technology to examine the molecular basis of aging in our population. This includes looking at telomeres that act as protective caps on the ends of chromosomes; DNA damage, and markers of ‘oxidative damage’.

Examples of our efforts to understand the processes of Senescence and Aging in Banded mongooses include Vitikainen et al 2016 and Blount et al 2015

Causes and consequences of reproductive conflict among females

 

Banded mongooses are unusual because most adult females reproduce in each breeding attempt. This contrasts with other cooperatively breeding mammals such as meerkats, African wild dogs and naked mole rats, where there is a single dominant breeding female in each group, and other females are reproductive suppressed. Dominant females often enforce their reproductive monopoly by killing the offspring of any other females that give birth. In banded mongooses, we have shown that synchronous birth allows females to escape the threat of infanticide. When all females give birth at the same time in the same place, any dominant female that kills offspring risks killing her own young.

Examples of our ongoing research into female reproductive conflict in Banded mongooses include Thompson et al 2016 and Inzani et al 2016

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Variation in helping effort among group members

 

One puzzle about cooperative societies is why some individuals contribute much more to teamwork than others. In banded mongooses, some individuals (usually males) stay behind at the den day after day to babysit offspring while the rest of the group goes off to forage. These ‘superbabysitters’ are not more closely related to the offspring that they guard, so it is unclear why they provide so much more care than other group members of the same age or sex. Once the pups emerge from the den (at 4 weeks old) some group members form exclusive one-to-one caring relationships with specific pups. These ‘escorts’ guard, carry, groom and provision the offspring in their care. Again, some individuals do much more escorting than others. We are trying to work out why some individuals are much more caring than others. Is it because they received lots of care themselves when they were young? Or is it because they are hormonally predisposed to teamwork? These are some of the questions we are currently working on.

Examples of our efforts to understand individual variation in cooperative behaviours include Nichols et al 2012 and Sanderson et al 2015

Hormonal control of aggression and helping

 

We are interested not just in how behaviours evolved, but also the physiological mechanisms that control behaviour. We can measure levels of hormones such as oestrogen, progesterone, and testosterone in animals and correlate this with the behaviour that we see. In this way we can work out the hormones that influence behaviour, and determine why some individuals are more ‘stressy’ or relaxed than others, why some individuals are first into the battle when two groups fight, and why some males prefer to look after the babies rather than try to mate with females.

Examples of our research looking at the influence of hormones on Banded mongoose behaviour include Sanderson et al 2015 and Sanderson et al 2014

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The function of scent marking

 

Scent plays a crucial role in the lives of banded mongooses. They continually mark each other and objects in their territory. We have shown that each group has a distinctive scent which is a mix of individual odours, and that groups recognise and respond aggressively to the scents of their neighbours. We also have evidence that males use scent to monitor the reproductive status of other groups remotely, and raid other groups when females are in oestrus or they have young vulnerable pups in the den. We are currently investigating the use of scent to avoid inbreeding.

Some examples of our work on scent marking in Banded mongooses include Jordan et al 2010 and Jordan et al 2011

Social learning

 

In primate and human societies, behaviour is inherited from teachers and mentors, that is, through cultural inheritance. The same is true for banded mongooses. We have shown that mongoose ‘escorts’ pass on foraging traditions to the offspring in their care. Pups observe particular foraging techniques and then copy what they have seen when they grow up. We are currently testing whether some individuals are particularly influential within groups, and whether some individuals copy more than others.

Examples of are research on social learning and cultural inheritance include Muller & Cant 2010 and McAuliffe & Thornton 2012

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Decision making in social groups

 

One of the questions we are interested in is how groups coordinate their activities. Who decides which animals stay behind to look after the pups? Which individuals lead the group, and how do leaders emerge? Is behaviour controlled by dominant group members, or does group behaviour emerge as a consequence of each individual making behavioural decisions based on simple rules of thumb?

Examples of our work investigating group decision making in Banded mongooses includes Gilchrist & Russell 2007 and Furrer, Kunc & Manser 2012.

Vocal communication

 

Banded mongooses are very noisy animals. They constantly emit short grunts to keep in contact with one another while foraging, and have specific calls to alert their fellow group members to danger or to the presence of rival packs. We have shown that each individual keeps in touch with other group members by emitting a ‘tweet’ at regular intervals which tells others two pieces of information: who that individual is, and what they are doing. Thus the little grunts that we hear when following groups actually consist of a constant stream of status updates: ‘Suzy digging’ ‘Peter moving’ ‘Harry searching for food’ and so on.

Examples of our research into vocal communication in Banded mongooses can be seen in these two papers from 2013; Jansen, Cant & Manser 2013 and Jansen, Cant & Manser 2013.

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