Blue stick insects discovery in Madagascar


Achrioptera manga, one of two new Madagascan stick insect species discovered by Drs Glaw, Bradler and colleagues. Manga means 'blue' in the Madagasy language. Credit: Dr. Frank Glaw

From Frontiers in Ecology and Evolution:

Love Island: Flamboyant males get the girls on Madagascar

In two new species of rare giant stick insects, males turn livid blue or multicolored at sexual maturity — but why?

April 2, 2019

Summary: Scientists have discovered two new species of giant stick insect on Madagascar, whose males become dazzling blue or multicolored at sexual maturity. The researchers describe their rare and exciting findings, and wonder at the reproductive success of the least stick-like stick insects on the planet.

Biodiversity hotspot Madagascar is one of the world’s biggest islands, and home to some of its biggest insects. Now German scientists have discovered two new species of giant stick insect, living only in the dry forests of Madagascar’s northernmost tip.

One giant female measures a whopping 24cm — but it is the smaller males that are most striking. At sexual maturity these daredevils abandon their stick-like camouflage for dazzling blue or many-colored shining armor.

Writing in Frontiers in Ecology and Evolution, the researchers describe their rare and exciting findings, and wonder at the reproductive success of the least stick-like stick insects on the planet.

When two become four

“Nearly all of the 3000+ known species of stick insects try to be inconspicuous and just look like twigs,” says senior author Dr. Sven Bradler of the University of Göttingen, Germany. “There are a very few, very large exceptions — and we have just discovered a couple more of them.”

The authors re-examined specimens they’d previously identified as odd-looking examples of two existing giant stick insect species, whose adult males remarkably are bright blue or multicolored.

“These were similar in size — 15 to 24cm — but generally less spiny and a bit differently colored than typical examples of their kind,” explains Bradler. “Now genetic tests confirm that the quirky individuals are in fact two new species, distinct from the original two but part of the same group.” explains Bradler.

Bradler’s reclassification places members of this group of species as close evolutionary relatives to other Madagascan stick insects, rather than cousins from overseas as previously thought. This is a potentially major finding, as it challenges the prevailing view that sticks insects colonized Madagascar multiple times.

He who dares, wins

The discovery also prompted the researchers to wonder: what reproductive advantage do these males gain from their bright colors, that is worth exposing themselves to predators?

The first author Dr. Frank Glaw of the Bavarian State Collection of Zoology in Munich, and colleagues bred the new giant stick insect species in captivity to observe their behavior.

“Males of one species started mating attempts only when they achieved their bright blue color.”

This might suggest that the males use their bright coloring to attract a mate. However, it is hard to believe the males could find a mate before being eaten — unless their bright coloring acts as a deterrent to predators.

“Males searching for a mate have to move about more, so pretending to be a stick becomes tricky. Better perhaps to plump for the opposite: a brightly colored warning.”

Bright colors — suggestive of toxicity — keep safe vivid members of other typically camouflaged species, like lividly colored Madagascan frogs.

“In support of this, all stick insects have neck glands that [produce] repellant substances, and these are typically well-developed in brightly colored species. Alternatively, like the Madagascan frogs some giant stick insects may have developed the ability to accumulate toxins from their food.”

But testing these hypotheses will be tough, admits Glaw.

Bradler adds “More than one factor may have played a role in the evolution of this remarkably conspicuous coloration. So even with more data on mate selection, habits, predators, natural food plants, toxins produced by defense glands and possible accumulation of toxins among giant stick insects, finding evidence for these ideas may prove difficult.”

Colorful stick insects have a bright future

Whatever its function, the splendid coloring of the male giant stick insects could make them a strong flagship species to promote the unique biodiversity of Madagascar, and the need for its protection.

“Already the once-uncertain future of these two new species seems secured, with their forest habitat in northern Madagascar a hotspot for conservation priorities”, says Glaw. “It is vital to maintain awareness and motivation to keep logging at bay. This precious area also harbors the highest density of critically endangered reptiles in Madagascar and is home of one of the most threatened primate species in the world, the lemur Lepilemur septentrionalis.”

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Five new frog species discovered in Madagascar


An adult male Mini scule Madagascar frog resting on a fingertip. Credit: Photo by Sam Hyde Roberts

From the Ludwig-Maximilians-Universität München in Germany:

Five new frog species from Madagascar

March 28, 2019

Scientists at Ludwig-Maximilians-Universitaet (LMU) in Munich and the Bavarian State Collection of Zoology have named five new species of frogs found across the island of Madagascar. The largest could sit on your thumbnail, the smallest is hardly longer than a grain of rice.

Madagascar, an island a little larger than mainland France, has more than 350 frog species. This number of recognized species is constantly rising, and many of the newly named species are very small.

Mark D. Scherz, a PhD candidate at LMU Munich, and Dr. Frank Glaw, Head of the Herpetology Section at the Bavarian State Collection of Zoology in Munich, together with colleagues at the Technical University of Braunschweig and the University of Antananarivo have named five new species of tiny frogs found across the island. Their study appears in the online journal PLOS ONE.

The five new species belong to a group of frogs commonly referred to as ‘narrow-mouthed’ frogs, a highly diverse family found on every continent except Antarctica and Europe. Although most narrow-mouthed frogs are small to moderately large, many are tiny. In fact, the group includes the smallest frog in the world — Paedophryne amauensis from Papua New Guinea, mature specimens of which reach a length of only 7.7 mm. What’s remarkable is that, in the smallest frogs, “miniaturization” has evolved independently — often several times within a single region, as highlighted in this new study. Three of the new species belong to a group that is wholly new to science, which the authors have formally dubbed Mini. The other two new species, Rhombophryne proportionalis and Anodonthyla eximia, are also just 11-12 mm long, and are much smaller than their closest relatives.

“When frogs evolve small body size, they start to look remarkably similar, so it is easy to underestimate how diverse they really are,” says Mark D. Scherz, lead author on the new study. “Our new genus name, Mini, says it all. Adults of the two smallest species Mini mum and Mini scule are 8-11 mm long, and even the largest member of the genus, Miniature, at 15 mm, could sit on your thumbnail with room to spare.”

Finding tiny frogs in the leaf litter is hard work. “Calling males often sit one or two leaves deep and stop calling at the slightest disturbance”, says Frank Glaw. “It can take a lot of patience to find the frog you are looking for.”

Rare Madagascar ducks back in the wild


This 1 January 2019 video says about itself:

World’s Rarest Duck Has Been Reintroduced Into Wild

The world’s rarest duck has been saved from extinction after being reared in Madagascar in the first ever floating aviaries made from converted Scottish salmon farming cages.

Over the last seven years, around 100 Madagascar pochards were bred by British aviculturists on the island just off Mozambique. This month 21 of them have been successfully transferred to the wild to live on Lake Sofia in the north of the island. They had spent a week in the converted fish farm cages to protect them, get them accustomed to the environment and increase the chances of them returning when they can fly.

Staff from the Gloucestershire-based Wildfowl & Wetlands Trust and the Durrell Wildlife Conservation Trust say they have adapted well to the lake and the cages. They have been seen diving and flying, as well as mixing with other wild ducks, and have repeatedly returned to the aviaries where they are thought to feel safe.

With a wild population of now nearly 50, the duck may be even the rarest bird on the planet. The pochard was thought to have become extinct until it was rediscovered by American wildlife experts from The Peregrine Fund in 2006. Three years later teams from the UK organizations went over to Madagascar and helped rear some of the birds in captivity using a box and a Tupperware container as a ‘lake’.

For this reason, a plan was conceived to convert Scottish salmon-farming cages into the world’s first floating aviaries. After successful trials in 2017, the aviaries were shipped from the UK to Madagascar and assembled on Lake Sofia this summer. With much of the wetlands across northern Madagascar severely degraded due to human encroachment, conservationists have also been working to improve the condition of Lake Sofia. The state of the wetlands in Madagascar is so poor they would probably not survive if they left the lake. Consequently, the pioneering approach of using the cages helped ensure they settled on the lake and did not stray to less habitable environments.

The Madagascar pochard is a species endemic to the African island. While it was once common, widespread deforestation and water pollution caused by the arrival of humans on the island led to the decline in the species and the belief it had been entirely wiped out. The British organizations have about 80 pochards still in captivity, 21 have been released into the wild using the unique system of converted Scottish fish farm cages. A further 25 are believed to be living wild on the island.

Madagascar’s extinct elephant birds, biggest birds ever


This April 2018 video says about itself:

Elephant Birds || These Giants Roamed In Madagascar Until Just A Few Centuries Ago

Elephant birds were large to enormous flightless birds that once lived on the island of Madagascar.

They became extinct, by the 17th or 18th century if not earlier, for reasons that are unclear, although human activity is the suspected cause.

From the Zoological Society of London:

World’s largest ever bird has been named: Vorombe titan

Madagascar’s giant elephant birds receive ‘bone-afide’ rethink

September 26, 2018

After decades of conflicting evidence and numerous publications, scientists at international conservation charity ZSL’s (Zoological Society of London) Institute of Zoology, have finally put the ‘world’s largest bird’ debate to rest. Published today (26 September 2018) in Royal Society Open Science — Vorombe titan (meaning ‘big bird’ in Malagasy and Greek), has taken the title reaching weights of up to 800 kg and three metres tall, with the research also discovering unexpected diversity in these Madagascan creatures.

Until now, it was previously suggested that up to 15 different species of elephant birds had been identified under two genera, however research by ZSL scientists boasts new rigorous and quantitative evidence — that shows, in fact, this is not the case. Armed with a tape measure and a pair of callipers, Dr Hansford analysed hundreds of elephant bird bones from museums across the globe to uncover the world’s largest bird, while also revealing their taxonomy is in fact spread across three genera and at least four distinct species; thus, constituting the first taxonomic reassessment of the family in over 80 years.

Elephant birds (belonging to the family Aepyornithidae) are an extinct group of colossal flightless birds that roamed Madagascar during the Late Quaternary, with two genera (Aepyornis and Mullerornis) previously recognised by scientists. The first species to be described, Aepyornis maximus, has often been considered to be the world’s largest bird. In 1894, British scientist C.W. Andrews described an even larger species, Aepyornis titan, this has usually been dismissed as an unusually large specimen of A. maximus. However, ZSL’s research reveals Andrew’s ‘titan’ bird was indeed a distinct species. The shape and size of its bones are so different from all other elephant birds that it has now been given the new genus name Vorombe by ZSL.

Lead Author at ZSL’s Institute of Zoology, Dr James Hansford said: “Elephant birds were the biggest of Madagascar’s megafauna and arguably one of the most important in the island’s evolutionary history — even more so than lemurs. This is because large-bodied animals have an enormous impact on the wider ecosystem they live in via controlling vegetation through eating plants, spreading biomass and dispersing seeds through defecation. Madagascar is still suffering the effects of the extinction of these birds today.”

Co-Author Professor Samuel Turvey from ZSL’s Institute of Zoology said: “Without an accurate understanding of past species diversity, we can’t properly understand evolution or ecology in unique island systems such as Madagascar or reconstruct exactly what’s been lost since human arrival on these islands. Knowing the history of biodiversity loss is essential to determine how to conserve today’s threatened species.”

Analysing this data in a novel combination of machine learning combined with Bayesian clustering, Dr Hansford applied modern techniques to solve a 150-year-old taxonomic knot, that will form the modern understanding of these enigmatic avian megafauna. The revelation that the biggest of these birds was forgotten by history is just one part of their remarkable story.

If you encountered an elephant bird today, it would be hard to miss. Measuring in at over 10 feet tall, the extinct avian is the largest bird known to science. However, while you looked up in awe, it’s likely that the big bird would not be looking back. According to a brain reconstruction, the part of the elephant bird brain that processed vision was tiny, a trait that indicates they were nocturnal and possibly blind: here.

Rare silky sifaka lemurs re-released in the wild


This 20 September 2018 video from Madagascar says about itself:

Incredibly Rare Silky Sifaka Lemurs Re-Released in the Wild | BBC Earth

After inspecting these rare white lemurs, the scientists free them again, and discover a pleasant surprise. Narrated by David Attenborough.

Lemur study suggests why some fruits smell so fruity. A new test with lemurs and birds suggests there’s more to fruit odors than simple ripening. By Susan Milius, 2:12pm, October 3, 2018.

Extinct crocodiles of Madagascar


This 11 September 2018 video says about itself:

Voay is an extinct genus of crocodile from Madagascar and includes only one species—Voay robustus. Its name comes from the Malagasy language name for crocodile “Voay”.

Numerous subfossils have been found, including complete skulls as well as vertebrae and osteoderms from such places as Ambolisatra and Antsirabe. The genus is thought to have become extinct relatively recently during the Holocene.

It has even been suggested to have disappeared in the extinction event that wiped out much of the endemic megafauna such as the elephant bird following the arrival of humans to Madagascar around 2000 years ago.

V. robustus has been estimated to have obtained lengths up to 5 m (16.4 ft) and a weight of 170 kg (375 lbs). These estimates suggest that V. robustus was the largest predator to have ever existed in Madagascar in recent times.

Its size, stature, and presumed behavior is similar to the modern Nile crocodile (Crocodylus niloticus).

One unusual feature of V. robustus that distinguishes it from other crocodilians is the presence of prominent “horns” extending from the posterior portion of the skull. Another diagnostic characteristic is the near-exclusion of the nasals from the external naris. It had a shorter and deeper snout than the extant Crocodylus niloticus, as well as relatively robust limbs.

Because V. robustus shared so many similarities with the Nile crocodile there must have been a great deal of interspecific competition for resources between the two crocodile genera if they were to have coexisted with one another. It has recently been proposed that the Nile crocodile only migrated to the island from mainland Africa after V. robustus had gone extinct in Madagascar.