All over the world, people greet, talk, eat, dance and celebrate according to their own cultural practices. We’re not the only species with such traditions. Chimpanzees have rich cultural traditions that determine how they forage for food, communicate, groom each other and wield tools. Other species with their own local customs, including orang utans, monkeys, dolphins and killer whales, are all united by their vaunted intelligence. But another mammal with a comparatively smaller brain has just joined this cultural club – the banded mongoose.
Corsin Muller from the University of Exeter gave wild mongooses a plastic shell containing some food (like a reverse Kinder egg). He found that adults preferred to break into the shells using one of two possible tactics, and that they passed on these traditions to their pups.
The results earn some kudos for the humble mongoose, but they’re important because our evidence for animal traditions has always come from studies that compared the practices of wild populations, or that ran carefully controlled experiments in captive groups. This is the first time that anyone has used experiments to show that wild mammals pass on traditions by imitating one another.
Banded mongooses live in large groups of up to 40 individuals, who cooperate to find food and raise their young. Muller worked with five such groups in Uganda’s Queen Elizabeth National Park. Banded mongooses eat an eclectic menu of insects, centipedes, small reptiles, eggs and even mice. Many of their snacks come in a hard shell that needs to be cracked and mongooses do so either by biting them or smashing them against a stone or tree trunk.
Individuals have clear preferences about these two techniques. When Muller gave the adults his plastic shell, containing a mix of rice and fish, he found that some were exclusive biters, others only smashed and yet others used a combination. Critically, they were stuck in their ways. When Muller tested them three months later, they each showed the same preferences.
He also found these adults transferred their preferences to the pups who watched them. Banded mongoose pups form exclusive one-to-one associations with specific adults who act as their mentors. These adults are usually young males, who aren’t necessarily related to the pup, and the youngster will aggressively monopolise the attentions of these chaperones.
Around 2-4 months after the adults infiltrated their Kinder surprises, Muller gave their attendant pups (now independent) their own eggs to break into. Even though none of them had seen the toy eggs in the intervening time, they showed a significant preference for the technique that their mentors had used. Those who saw an adult bite the toys open did the same themselves; those whose mentors liked to smash copied that strategy instead; and those whose mentors had ignored their toy eggs were themselves uninterested. These preferences even persisted as the pups grew into adults.
Muller’s study expands on experiments with other captive species in a number of ways. In finding the same trend in all five groups of mongooses, he added some valuable replication to his study, which is often missing from experiments that focus on one group of captive animals. Muller showed that multiple traditions can coexist within a single population. And he showed that animals don’t need big brains to pass on traditions across the generations. It may be that such traditions are more commonplace than previously thought.
Reference: Current Biology http://dx.doi.org/10.1016/j.cub.2010.04.037
Photo by Reini68; video by Corsin Muller
More on animal cultures
- Chimps prefer to copy others with prestige
- Culture shapes the tools that chimps use to get honey
- How dolphins prepare the perfect cuttlefish meal
June 3rd, 2010 at 5:33 pm
Good stuff! And human hubris is dealt yet another blow
I’m pretty sure our local population of Australian magpies (Gymnorhina tibicens) transmits culture: The adults (both parents and others of the breeding commune) seem to deliberately teach their young to take food from us; in so doing, they make the young stay even though we come much closer than they tolerate other humans to their young. Must see if I can get funding for a study …!
By the way, am I the only one who feels that the plural of “mongoose” really OUGHT to be “mongeese”?
June 3rd, 2010 at 9:57 pm
Yahya: mongoose is from sanskrit “mangus”, and so not originally old english (as “goose” is). different language origin, different inherited inflection (same as with “moose”, which is from penobscot algonquian or something)
June 4th, 2010 at 3:50 am
Interesting – but it should be noted that both techniques (smashing AND biting) come about without the need for imitation in this species. So one should not call this culture – it is more of a canalization of what this species can do.
June 4th, 2010 at 5:27 am
Cool article about cool science.
June 4th, 2010 at 9:49 am
Kai,
I would like to start by noting that I am not a mongoose. So, I don’t take particular offense at your restrictive definition of culture combined with an much more overly broad definition of canalization. But, if we’re talking semantics, you would be better off saying “this could *just as well* be called canalization.
That being said, this is much more certainly “culture”. It is knowledge on the correct way of doing things, passed down from generation to generation through instruction (not experimentation). It lacks some of the vestigial nature of “advanced” human cultural trappings, but it is, most certainly culture.
This behavior can be seen in many species, as noted in the article. In fact, passing knowledge is a basic animal trait. Humans define ourselves by our tremendous capacity for culture, the same way an elephant might define itself by it’s exaggerated trunk. But, to say that other animals don’t have this trait (a function of the same basic brain that we have) would be as foolish as an elephant saying other animals do not have noses, because they are too small.
Your fundamental argument, that it is not culture simply because it was started by somebody is obviously flawed, as even our own cultural trappings did not always exist. They must have been, at some point, created without the need for imitation. By your definition, no creature could posess culture.
June 4th, 2010 at 9:56 am
Yeah, but isn’t that exactly what a mongoose would say? HM?
June 6th, 2010 at 6:39 am
Yahya, the classic example of bird behavior being passed on (similar to your magpies) is the observation made in Britain during the 1960′s that blue tits were cream thieves.
“In Britain milk used to be delivered to every household by the ‘milkman’. The bottles would remain on the doorstep until people got up. Back in the 1960’s people began to notice holes in the foil caps, and soon the culprits were identified as Blue Tits grabbing an early breakfast of cream. This learned behaviour was taught to young Blue Tits, and no milk bottles were safe. People began to get the milkman to leave the bottles in ‘Tit-proof’ boxes, or to cover the tops in some way. Subsequently people became more ‘health-conscious’, and the switch to low-fat milk did not please the Blue Tits. Add that to the fact that most people in Britain now buy their milk in cartons from supermarkets and you have the explanation for why this behaviour seems to have almost died out.”
June 6th, 2010 at 6:47 am
Actually, the blue tits ARE a classic example but more for how difficult it is to study observational learning. The spread of the behaviour is clear but there’s no good evidence AFAIK that the tits were actually *teaching* each other or even copying each other. An equally plausible alternative is that birds were directing each others’ attention to the milk lids, and each one was then independently discovering the pecking behaviour. If I wasn’t out for the day, I’d try to find a link for this. Maybe later, unless someone beats me to it.
June 8th, 2010 at 4:02 am
@ Ed: Here is one reference: http://doi.apa.org/?uid=1991-11889-001, a Galef paper on the tit-milk phenomenon. Basically what was shown is that the tits learned the milk-bottle opening behaviour on their own, and where mainly influenced by others being present near these bottles.
@ Matt: …and work like that of Galef is crucial here: what if the mongoose’ default is to always bite new food types, unless a tree is somehow involved when another one deals with that food. “If a tree is involved, throw the food instead” would be a rule that would work just fine, especially given that there seem to be only these two opening styles available to mongoose. Would you call this culture? I think more studies would be needed before one would say so. We need to know precisely how the mongoose learns these behaviours (or perhaps only one of them). But the fact that both opening styles are already present without demonstration reduces the likelihood that anything major is being passed on here for any of these two behaviours. Sorry if I did not make myself clear the first time.