The world's cutest mammal?

There are surely many contenders for this title.
But up there with the best of them are mouse lemurs.

Now mouse lemurs don’t get much publicity. Compared to the hype dealt out for kittens, koalas, puppies or pandas, mouse lemurs suffer a media blackout. In fact, their only real public appearance was in the animated movie Madagascar, where Mort - the mouse lemur - was ‘Plan B’ should the lion Alex find sushi unpalatable.



Mort from Madagascar. Apart from his diminished dentition and propensity for bawling (oh such blatant exploitation of our nurturing instincts), he’s a reasonably accurate rendition of the mouse lemur genus (Microcebus).


As their name suggests, mouse lemurs are petite. They’re actually the world’s smallest primates. Pop them on balance (the scales-of-justice type) and you’ll need three of the little blighters to counterbalance one pygmy marmoset (and I know you thought they were teeny).

Being so eminently bite-sized (30-70g/1-2.5 oz depending on the species), mouse lemurs only come out under cover of darkness. So if you want to see one, you must venture out by torchlight.

My first encounter with a mouse lemur took place in a thicket of ‘spiny forest’ at Berenty Reserve in southern Madagascar. Now skulking about in the dark in a habitat that’s renowned for its thorniness isn’t actually as unpleasant as it sounds. In fact, for someone accustomed to the weapon-toting plants of Africa (designed to decorticate rhinos, elephants and giraffes), Madagascar’s thorny scrub is something of a cake walk. We’d only begun edging our way through the prickles when a searing flash of eye-shine leapt from the darkness. There, just at eye-height, crouched in the spiky shrubbery, was a stunning little animal.

A small piece of fluff with huge radar ears and large soulful eyes, it sat gazing at us, swivelling its ears back and forth (independently) as we appreciatively ‘ooohed’ and ‘ahhhed’. Its was a grey-brown mouse lemur (Microcebus griseorufus) and a ringer for a lesser bushbaby (although a third the size and more... well, mouse-shaped). As it sat there tremulously, looking at us with huge puss-in-boots eyes, it seemed so small and vulnerable I began to worry about our intrusion upon its life. Should we really be shining spotlights into those fathomless eyes?

It was at this moment that a moth fluttered down into the pool of light. With lightening speed, the little lemur reached out and snatched the insect from the air. Clasping its victim tightly in one fist, it bit off the head, and - still gazing at us - sat chomping away (very succulently) with its sharp little teeth.

Er, well maybe not quite so innocent and vulnerable...

My inept photograph of a grey-brown mouse lemur (Microcebus griseorufus). Fifteen species of mouse lemur haunt the forest (remnants) of Madagascar (ten of these were described since 2000).

Another of my out-of-focus photos of a grey-brown mouse lemur. Although quite svelte in October (after the cool dry season), mouse lemurs indulge in ‘opportunistic fattening’ (a concept I’m familiar with). They can double their body weight during the wet season, laying down fat in their tail (which I’m also familiar with).

Now this little mouse lemur was the first of about a dozen that we encountered on a one-hour night walk. I’m ashamed to say that we started greeting the flare of eye-reflected torchlight with,

“Oh, it’s another grey-brown mouse lemur.”

You see mouse lemurs favour high density living where conditions are good (up to 300 per sq km/780 per sq mile). Nevertheless, we only met singletons because they prefer to go a’hunting (mostly for bugs and fruit) alone.

But don’t you start imagining that they lead solitary lives. Mouse lemurs enjoy a social network that’d rival anything on Facebook. Like elephants, the girls stick together in big clans of grannies, daughters, aunts and nieces; all sleeping snuggled together by day (up to 16 per tree-hollow for grey mouse lemurs). Friends and rellies not only huddle and groom one another, they happily suckle each other’s sprogs. Even the guys, who head out to seek their fortune as adolescents, tend not to sleep alone. This saves on heating bills: mouse lemurs dozing in pairs use 20% less energy and trios enjoy an energy-saving of 40%.



When times are tough, grey mouse lemurs (Microcebus murinus) know how to wind down. Day or night, they can slip into torpor, dropping their body temperature to 12 C (54 F). These daily bouts of indolence (which last an average of 9.3 hours) reduce the lemur’s calorie needs by 38%. Of course, they can also opt for proper hibernation (and most females do).
Photo by Joshua Bousel.



The hazards of the night. Owls, like this white-browed owl (Ninox superciliaris), are very fond of mouse lemurs. In parts of southern Madagascar (e.g. Beza Mahfaly) they munch their way through a quarter of the population annually.


This is all well and good, but mouse lemurs kip in lots of different hidey holes, so how do potential bedfellows reunite after a night of solitary hunting?
They snoop and sniff.
Mouse lemurs don’t possess scent glands but they make the most of what’s on hand (literally). Saliva, faeces, urine and genital secretions are all smeared about strategically, to inform noses-in-the-know of each lemur’s identity, libido, property rights and level of alarm. Oh, and these fragrant little lemurs also like to urine-wash (the term says it all).

However, it’s acoustically that mouse lemurs really come into their own. Yodelling eight different types of call (plus a few ultrasonic ones that are beyond us), they coordinate group movements, importune lovers and warn of incoming owls. Studies have found that the ‘contact trill’ given by golden-brown mouse lemurs (Microcebus ravelobensis) seeking a dawn rendezvous is unique and consistent for each sleeping group (so no one ends up in the wrong bed). And the same is true for the seductive warbles performed by male grey mouse lemurs out on the prowl. What’s more, new guys on the block imitate the calls of resident dudes to hasten their acceptance in the neighbourhood!

The grey mouse lemur’s (Microcebus murinus) mating season is seriously hectic, and males prepare by increasing their testes size 5-10 times. The females are promiscuous but accept lovers for only one night. Enticed by a lady lemur’s lascivious trills, Romeos engage in ‘scramble competition’, and the successful ones knobble their successors by leaving behind sperm plugs.
Photo by A J Haverkamp.

I was blessed with another sighting of a mouse lemur in the rainforest of Ranomafana National Park. Here the local guides smear banana along the trunk of a roadside tree so three busloads of tourists can jostle one another for photographic opportunities. However, despite the less than inspiring circumstances, the resident brown mouse lemur (Microcebus rufus), who zipped in soon after nightfall, couldn’t fail to enchant.

Moving faster than the eye could follow, this tiny creature leapt and flitted from liana to branch to trunk to twig. It darted up and down in a fever of constant movement, pausing only for the briefest licks of banana paste. Of course photographing this amazing animal was way beyond my skill, so I’ve included a couple of images taken by more competent visitors so you can share in the experience.




A brown mouse lemur (Microcebus rufus) enjoying its offering of smeared banana. Photo by Leonora Enking.



Brown mouse lemurs (Microcebus rufus) at Ramonafana National Park are known to munch 69 different kinds of fruit (I’m unsure whether this includes the banana). The fat-rich mistletoe, Bakerella, is a mainstay of their diet.
Photo by Frank Vassen.

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 So now you’ve met mouse lemurs, what do think?

Where would you place them on the mammalian-cuteness-scale?

Before deciding, please bear in mind that these little critters are full-grown adults, and it’s quite unjust to compare them to the bumbling, blunt-nosed infants of other species (i.e. all those nauseatingly saccharine kittens and bunnies).