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Madagascan Miscellany

For the whole of October, The Nature Nook has been looking at Madagascan wildlife. We’ve already looked at lemurs, fossas, tenrecs, and the smallest reptile in the world, among others – but the end of the month is rapidly approaching and we still have many more weird and wonderful Madagascan creatures to cover. So today we are posting a ‘Madagascan Miscellany’ – a list of eight strange animals that live on this great island, from a chameleon that only lives for five months to an ant that sucks the blood of its own larvae…

But be warned: we’ve thrown in one animal that doesn’t actually live on Madagascar. Read on to find out why we’ve included it…

1. Giraffe Weevil

Madagascar, as we have already seen this month, is home to quite a few oddities, but few are as weird-looking as this insect: the giraffe weevil.

The reason for the giraffe weevil’s naming is instantly obvious: the male has an extremely long, spectacularly disproportionate black head and neck, which he holds angled from his body like a tiny construction site crane. The neck, together with the head, makes up 70% of the insect’s overall body length.

And what do the beetles do with these elongated necks? They nod, of course. The males partake in nodding contests, trying to out-nod their opponents in ritualised fights until one emerges victorious. This means that the males with the longest necks (better for nodding, you see) are selected by the females. If nodding alone doesn’t see off a rival, two males may have to move to the next stage – they push and wrestle one another with their necks until one of them finally backs down.

The female giraffe weevil has a more modestly-sized neck – it’s only half her total body length – and she uses hers for construction, almost like a robotic arm. This beetle feeds and raises its young on just one particular type of tree, so the female deftly rolls up appropriate leaves using her neck to create protective egg cases, which resemble green cigars. She will even create small notches on the leaves to create a strip to ensure that it all sticks together. In essence, the female giraffe weevil invented Velcro long before we did.

After laying a single egg inside this little leafy tube, the female beetle snips it from the tree so that it falls to the ground. When the larva hatches, the leaf will provide it with protection and sustenance for the first few days of its life.

2. Leaf-Tailed Gecko

Most geckos are nocturnal creatures. In India, many species live around and even inside people’s houses, having realised that the lights used by humans to illuminate their homes at night attract large numbers of flying insects, which the geckos hunt. But being active at night means that geckos need to rest during the day, so during this time many species rely on a disguise to remain undetected.

The leaf-tailed geckos of Madagascar are perhaps the masters of this, opting to make themselves indistinguishable from the plants that they live on. The mossy leaf-tailed gecko is so well camouflaged when it is sitting on a branch that it is virtually impossible to detect, even when you are a few centimetres away and actively looking for it. The level of realism is astonishing. Its blotched brown body almost perfectly matches the colour and pattern of the bark on which it sits, right down to the lichens and moss growing on the tree. And, as its name suggests, its tail looks like a leaf – a dead one at that, with ragged edges and a central vein.

But an object, no matter how well disguised it is, can still be discovered if it casts a shadow – so the gecko has an irregular, skirt-like frill of skin, a ragged fringe, around the edge of its body and along its tail. When the gecko presses itself flat against a tree, the lower edges of these membranes seem to meld into the bark, eliminating the lizard’s shadow and making its outline practically invisible, transforming the animal into an inconspicuous swelling of the rough surface of the tree trunk.

3. Tomato Frog

There are no prizes for guessing how the tomato frog got its name. It’s round, and it’s a bright red or orange colour. Conspicuous colours and markings are used by many creatures to advertise to potential predators the fact that they are poisonous or taste unpleasant, and it’s a universal signal that is understood across the entire animal kingdom. When the tomato frog feels threatened, it inflates its body, puffing outward to make itself look bigger, and it oozes white, sticky glue from its skin. If another animal grabs a tomato frog in its mouth, this thick, irritating secretion gums up the predator’s mouth, forcing the attacker to drop its prey. In some cases, the predator may not be able to eat properly for several days afterwards.

4. Labord’s Chameleon

This small, pointy-nosed chameleon, which lives in the spiny forests in the southwest of the island, only lives for four or five months – the shortest lifespan ever recorded for a four-legged vertebrate. After the babies hatch from eggs in November, they grow up to 2.6 mm a day and reach maturity within two months. Then they mate and lay eggs. By late February or early March, they are all dead. Beyond this point, the species is represented solely by developing eggs that won’t hatch for another eight months, which means that Labord’s chameleon spends most of its existence as an egg. This reptile lives in a very dry, unpredictable part of Madagascar, so perhaps it pays to remain in the stable environment of the egg until conditions are just right.

5. Bamboo Lemur

Lake Alaotra is Madagascar’s largest lake, covering an area the size of Washington, DC. It is also home to several endangered animals found nowhere else on the planet – including the only primate in the world adapted to living in reed beds. This is the very rare Lac Alaotra bamboo lemur, which has a thick coat of brown and grey fur, and a long tail that provides balance as it moves between the reeds and floating vegetation of its marshy habitat.

Despite its name, the Lac Alaotra bamboo lemur doesn’t eat bamboo (at least in the wild) because bamboo no longer grows around the lake where it lives. Instead, it eats mainly reeds and papyrus. However, there are a few other species of bamboo lemur and they do eat bamboo. The bamboo that grows on Madagascar is even more protected than in other parts of the world because it is loaded with cyanide. Nonetheless, these lemurs eat hardly anything else. Most bamboo lemurs prefer parts of the plant that are low in poison, but one species, the golden bamboo lemur, actively consumes the parts that are packed with cyanide. How they detoxify such a potent poison is still unknown, for the same amount would very quickly kill a human being.

Historically, bamboo lemurs were called ‘gentle lemurs’, although this is a bit of a misnomer because they can actually be extremely aggressive, especially in captivity. In 1851, these lemurs were placed in a genus called Hapalemur – named for their resemblance, both in small size and proportion, to marmosets, which at the time were in the genus Hapale. But there is a similar word, hapalos, of Greek origin, which means ‘tender, gentle’ – and this is likely the origin of the name ‘gentle lemur’. Since the start of the 21st century, however, ‘gentle lemur’ has seen little use in both popular and academic literature, probably because these lemurs are not as placid as this name would suggest, and they have instead largely become known as ‘bamboo lemurs’.

6. Madagascar Pochard

Lake Alaotra was also once home to what is possibly the rarest duck in the world: the Madagascar pochard. Although apparently quite common on the lake during the early 20th century, its population began to plummet due to introduced predatory fish, hunting, and the transformation of the land surrounding the lake to make room for cattle and rice cultivation. The last confirmed sighting of a Madagascar pochard on Lake Alaotra was in 1991. This single male was captured and kept at Antananarivo Botanical Gardens until his death a year later. Intensive searches that lasted until the dawn of the 21st century failed to produce any more records of this bird and it was believed to have gone extinct.

Then, in 2006, a small flock of Madagascar pochards was unexpectedly discovered in a cold crater lake in a remote area of northern Madagascar, some 300 km north of Lake Alaotra. But this final refuge was not really suitable for the ducks – the lake was too deep and too cold for them to thrive, and there was an extremely high death rate among the ducklings. With only around 20 pochards clinging to survival here (and only six females), it was decided that a relocation attempt was needed to stop the species from becoming extinct for real.

In 2009, an international team removed Madagascar pochard eggs from the wild and started a captive-breeding program. By 2017, the population of captive birds had reached 90 individuals. And in December the following year, 21 ducks were released into the wild, this time at a more suitable location, Lake Sofia, where floating aviaries had been installed to protect the birds. In November 2019, less than a year later, the ducks successfully bred. This is undoubtedly a huge victory for conservation groups that have been working for more than a decade to save the species, but with a total population measurable in the dozens, the Madagascar pochard’s existence is likely to remain precarious for quite some time.

7. Noseless Lemur

There are many badly named animals in the world. The mountain chicken, for example, is actually a large species of frog. The bearded tit, meanwhile, is neither bearded nor a tit. But the so-called ‘noseless lemur’ has quite possibly the most erroneous name of them all. It has nothing to do with lemurs, primates, or even Madagascar – but its story is so interesting, I just had to include it on the list.

A fossilised fragment of this extinct animal, which lived between 6 and 9 million years ago, was discovered by Argentine naturalist Pedro Scalabrini, who, in 1898, sent it to palaeontologist Florentino Ameghino for analysis. However, Ameghino had trouble identifying the fossil because it was still mostly encased in rock, so he classified it as an archaic type of lemur that, very unusually, seemed to almost completely lack a snout. He named it Arrhinolemur scalabrinii, which translates to ‘Scalabrini’s lemur without a nose.’

But this fossil came from South America. Lemurs, as we know, only live in Madagascar. Even lemur-like primates have no connection to the once-isolated continent of South America. So this strange fossil made no anatomical, evolutionary, or geographical sense. It didn’t resemble any other known species and was entirely in the wrong place. Was this indeed a very wayward lemur? Or simply a case of mistaken identity?

In 1945, American palaeontologist George Gaylord Simpson studied the fossil and suggested that it might not be a lemur at all. In fact, he didn’t think it was a primate or even a mammal. He proposed that it was actually an ancient fish. Over time, other scientists came to the same conclusion. Finally, in 2012, a proper taxonomic study was conducted on the specimen, concluding that it was indeed an extinct species of fish, and the ‘noseless lemur’ was given a new name, Leporinus scalabrinii.

8. Dracula Ant

Halloween may still be almost a week away, but that won’t stop us from finishing today’s post by looking at an animal that exhibits some grisly and (literally) bloodthirsty behaviour: the spooky-sounding Dracula ant.

When it comes to eating, ants have a bit of a problem. They have extremely skinny waists through which their digestive tract must pass. Solids would easily get lodged in this bottleneck and kill them, so ants cannot eat solid food. But solid food is a great source of protein and so ants must find a way of converting it into a more accessible liquid form.

Many ant species bring back solid food and give it to their larvae, which digest it and then later regurgitate the mushy remains for the adults to lap up. It’s a sensible solution, but this behaviour only appears in some of the more modern ant lineages. The Dracula ant is a much more ancient species of ant, and members of one of these colonies have a more… extreme method of getting their protein. Instead of eating regurgitated food, they tap right into the source.

Adult Dracula ants bring small invertebrates back to the colony for their larvae to eat as per usual, but then things take a rather macabre twist. The ants chew holes in their own larvae and suck out the protein-rich haemolymph, the insect equivalent of blood. The larvae often attempt to flee when hungry adults enter the nursery chamber, perhaps knowing what is coming next and indicating that they aren’t too fond of this treatment. But there is little they can do to avoid it. The adults don’t actually kill the grubs, though; after drinking some of a larva’s haemolymph, an adult moves on and allows the grub to recover. This is known as ‘non-destructive cannibalism’, and many Dracula ant larvae have scars on their bodies from these grisly acts.

In the next (and penultimate) Madagascar Month post, we’ll be looking at a leaping lemur that lives in a truly bizarre landscape – the sifaka.