Monday, December 11, 2017

Lemurs of Ranomafana

Madagascar captured my imagination as a young girl and never let go. Maybe it was watching Zoboomafoo, a kids' nature show starring a wacky Coquerel's sifaka---both a puppet and a real lemur. Maybe it was walking into Fin and Feather, a smelly pet shop in the University District of Seattle, to buy food for my sister's mouse and getting distracted by the knobby old chameleon next to the register. Maybe it was going to Woodland Park Zoo and heading straight for the Standing's day gecko enclosure because I couldn't get enough of that baby-blue lizard that climbs straight up glass. More recently, images of massive-trunked baobabs and spiny octopus trees have compounded my fascination.

All those influences put together are the reason why Madagascar became a stop on my Watson itinerary, and I can't wait to share them all with you. I'll start, to get 'em out of the way, with the charismatic megafauna. Photos of lemurs have been the item most requested by my friends (followed by requests for photos of me in the field---but a great ape is so boring compared to prosimians!)

Ranomafana National Park and the fragments of rainforest surrounding it are home to seven species of diurnal lemur and four genera of nocturnal lemur. Here they are!


Red-Fronted Brown Lemur (Eulemur rufifrons)


My first diurnal lemur sighting! I tagged along with the study-abroad group from Stony Brook University, and we were treated to a very close encounter with some curious and agitated red-fronted browns.

It was fun to be with a bunch of lemur nerds who'd recently taken an exam on lemur nomenclature. What better way to learn the Latin and English names of all the prosimians?

The female has a gray face with white mutton-chops and a dusty-gold crown.

The male has a striking black nose and a carrot-top hairdo.

Acrobats!

I like this photo because it shows how nimble our cousins can be, running across tree limbs high in the canopy.

Like most diurnal lemurs, red-fronted brown mothers carry their babies piggy-back style. (Actually, the baby clings to the belly for the first month of life, and then it crawls around to the back when it's strong enough.) I was blown away by the cuteness the first time I saw a little black-and-orange face peeking out of its mama's fur.

Females do most of the heavy lifting, but males are very involved in childcare. Here's a father grooming his mate and baby.

One day I was walking through the rainforest alone near our research camp, and a troupe of 12 red-fronted brown lemurs galloped overhead, snorting like pigs. When they saw me, they stopped to glare at me.

The lemurs swished their tails back and forth in a very pointed gesture of irritation. Maybe you can see the motion in this photo? Can you feel their agitation? It was like an impatient librarian was tapping her foot and breathing down my neck, way out there in the rainforest!

Red Bellied Lemur (Eulemur rubriventer)


The red bellied lemur is closely related to the red-fronted brown lemur, but you can tell the difference in the male's faces. Notice the white teardrops and black nose here.

Lemur feet are the COOLEST. Why, what a bulbous thumb pad you have!

On a birdwatching tour with Menja and her boyfriend, Rhodan, we noticed this strange youngster. It should be dark brown, but instead it had light caramel fur, no dark facial markings, and slightly pale eyes. Maybe an albino or leucistic individual?? 

Here, the light-colored juvenile clambers through a tree fern after a typically-colored juvenile of the same size. This photo gives a nice comparison of the two, but what I really like is how it captured the lemurs' relationship to tree ferns. I love this plant, and I wish I could grasp its prickly branches and swing through its drooping fronds with grace.

Ranomafana Bamboo Lemur (Hapalemur griseus ranomafanensis)


The Ranomafana bamboo lemur (a subspecies of the eastern lesser bamboo lemur) is one of three species of bamboo lemur living in Ranomafana National Park. Take a moment to think about that: these are primates living on tough, tall grasses! They have been called the "giant panda of Madagascar" because they fill the same ecological niche.
  
These fluffy lovebugs are also known as "gray gentle lemurs," presumably because their grass-munching habits don't require violence. Ironically, this was the only species of lemur I witnessed fighting. Two troupes of about eight lemurs each clashed over my head on a morning bird-walk.


Golden Bamboo Lemur (Hapalemur aureus)


Here is a golden bamboo lemur, being golden and eating bamboo, how fitting!

This species was discovered in 1986 by Dr. Patricia Wright, the founding director of Centre ValBio (the lab where I work) and PhD advisor of Dr. Sarah Zohdy (my own research mentor). All this interwoven history made my chance to see a golden bamboo lemur even more exciting.

Greater Bamboo Lemur (Prolemur simus)


The greater bamboo lemur is a sluggish, easy-going guy.

Like the other bamboo lemurs, he's a vertical climber. Can you imagine clinging to the top of a slick, bendy bamboo pole and feeling as comfortable as if you were lounging on a couch?


These three bamboo lemurs pose an ecological quandary: how do three species with the same diet coexist? Why doesn't one species outcompete the others? Last month, while sitting on a log near the village of Bevoahazo, I devoured a book on this subject and many others: The Song of the Dodo by David Quammen. Currently obsessed. Highly recommend.

Anyway, the answer lies in the fact that these three lemurs each specialize in different parts of the bamboo. The Ranomafana bamboo lemur prefers leaves, the greater bamboo lemur uses its hefty teeth to crack open stems and gouge out the inner pith, and the golden bamboo lemur consumes the new shoots and creepers.

But the plot thickens: the new shoots are overflowing with cyanide, bamboo's chemical defense against herbivory. Every day, the golden bamboo lemur consumes 12 times the lethal dose of cyanide for other animals of its size! As far as I know, how they do that is still a mystery.

Once I knew about the arms-race between a poisonous, tree-sized grass and its cyanide-immune connoisseur, I had to get a photo with Ranomafana's bamboo. I forgot to take any lemur selfies, but really I'd rather pose with this symbol of sympatry and evolution anyway!

Milne-Edwards' Sifaka (Propithecus edwarsi)


The sifakas, pronounced "shi-faks," are the largest living lemurs after the Indri. (Did you know that there are also 17 species of giant lemur, all of which went extinct in the last few thousand years?)

I got to watch this individual bound through the trees with jaw-dropping leaps. The Milne-Edwards' sifaka is the long-jumper of the canopy. It starts on one tree with it belly toward the trunk. It then shoves off with its powerful legs, swinging its tail and one arm forward for momentum. It flies up to 30 feet through the air before landing, hind-legs first, on its target tree. While it flies, it does a 180-degree twist so it can land with its belly facing the new trunk.

There she goes!

The sifaka's little-old-man face made me want to laugh, but it also held a sort of sorrow.

No other species of lemur made me feel as much kinship as this one. I am often hit with a wave of desire to prevent the extinction of the lemurs because of their unique traits, evolutionary history, and ecological roles. But in this moment, it was a simpler and more painful desire. I felt compassion for this fellow primate and her shrinking home.

Black-and-White Ruffed Lemur (Varecia variegata)


My favorite lemur species is this one, the black-and-white ruffed lemur. I only glimpsed it once, but I heard its looping, erratic song all through the forest, and even in some of the fragments where I camped. Turn on your volume for this video!


Brown Mouse Lemur (Microcebus rufus)


Finally, we get to the nocturnals! Underappreciated, small, plain and brown, these lemurs have my heart. Of course, we have to start with my study subject and the world's smallest primate, the mouse lemur. (Technically, the smallest primate is the Madame Berthe's mouse lemur of western Madagascar's Kirindy forest, weighing just over one ounce. I study the brown mouse lemur, which weighs closer to 1.5 ounces.)

A brown mouse lemur playing peekaboo from an introduced Chinese guava, or goavy sinoa. This genus is truly the mouse of lemurs: it thrives in forest edges, degraded habitats, and even the weedy bushes that sprout in fallow fields.

When we trap and handle these animals, we use red light to be gentle on their wide, nocturnal eyes.

We expose them to white light only for their headshots, a front view and profile.

The most striking features of these lemurs are their grabby little fingers. The fingertips have circular pads like a tree frog! The pads aren't sticky like a frog's, or molecularly attracted to smooth surfaces like a gecko's, but these little lemurs have a powerful grip force.

They also have a powerful bite, hence our thick gloves!

Most of the lemurs we caught were feisty and healthy, but this poor male was nearly hairless, covered in lice, and very skinny. We named him Dadabe, or Grandpa. He was a stunning example of variation. We often think, "Brown mouse lemurs look like this, or that," but really they are diverse individuals. I wonder what genetics or life experiences predisposed Dadabe to his sickness?

This is Thief, a remarkably bold mother. One evening, we were sitting around the campfire when Menja flashed her light up at our supply of bananas, which we use to bait the lemur traps. "Volavo!" she shouted, "Rat!" But wait, it was a little mouse lemur, nibbling on our fruit and looking guilty. She scurried away under our flashlight's beam, but we set out a trap and, sure enough, she was in it the next morning. That's why her name is Thief, and why we have this rare photo of a mouse lemur in the daylight.


Greater Dwarf Lemur (Cheirogaleus major)


Twice in the same night, we peeked into our traps and found not the petite muzzle of a mouse lemur, but the pudgy face of a greater dwarf lemur!

These lemurs can be ten times the mass of a mouse lemur. This one barely fit in the trap! It furry body was stuffed inside like a big teddy bear stored by its child in a small mailbox. Nonetheless, it didn't seem distressed, only bewildered.

"Can I have this branch?"

"Somebody's holding my tail... but, at least I got a free banana!"

Wait... those aren't lemurs!


The red forest rat (Nesomys rufus) is a large, frugivorous rodent endemic to Madagascar. It's one of the world's only monogamous rodents. And it's terrestrial, so we never caught one in our lemur traps.

The Tanala tuft-tailed rat (Eliurus tanala) is another endemic rodent. It has a wonderful white tuft on its long, bendy tail.

Unlike the red forest rat, the Tanala tuft-tailed rat found itself lured into our banana-baited traps quite often. We were always pleased to watch the Tanalas trot away to freedom when we let them go. (We were less delighted to watch the invasive black rats saunter away into the forest.)

Ring-tailed mongoose (Galidia elegans), or vontsira mena in Malagasy. Recent DNA work shows that this mammal isn't a mongoose at all. In fact, all Malagasy carnivores belong to a single endemic family, Eupleridae, that began when a single animal rafted across from Africa between 18 and 24 million years ago.

In the course of our research, we encountered a number of other mammals: a lowland streaked tenrec that looked like a hedgehog squirted with mustard; an eastern woolly lemur clutching a branch like a spooked child; a Webb's tuft-tailed rat with a black tuft instead of a white one. The wondrous mammals of Madagascar are only the tip of the iceberg. Stay tuned for the frogs, lizards, and strange plants that really start to get interesting!

3 comments:

  1. fascinating, can't wait for the next one ... frogs, lizards, and strange plants.

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  2. Just clicked on an image to get the higher resolution slide show.

    The immunity to cyanide is pretty mind blowing. Wonder if it makes them toxic to predators?

    Otzi the five thousand year old ice man mummy had higher than normal levels of arsenic in his tissues from copper mining ...nothing like what these lemurs can tolerate, but given time, would a group of humans evolve into mole-like miner people immune to high levels of arsenic? Somebody should write a sci-fi story about that, oh wait, somebody already did--Mote in God's Eye, The Time Machine : )

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  3. Interesting comments Russ...

    Lemurs rock!
    Jeanette

    ReplyDelete