IL SEGRETO DELL’UCCELLO ELEFANTE: L’UOMO IN MADAGASCAR GIA’ 10.500 ANNI FA?

Il Madagascar ha – diciamo da sempre – una serie di "capisaldi" per quanto riguarda la sua biogeografia e la sua storia, entrambi peculiari. Uno di questi e’ senza dubbio il fatto che si riteneva che la colonizzazione umana fosse davvero molto recente, valutabile intorno a 2.500-4.000 anni fa. Una bazzecola, considerata la vicinanza dell’isola al continente africano. Sostanzialmente la versione che veniva fornita era quella di una colonizzazione da parte di immigranti indonesiani e malesiani, a cui poi si sono aggiunti degli africani. Cio’ e’ confermato dal fatto che la lingua malagasy e’ di fatto un dialetto del Borneo (dunque austronesiano) e non africano e dall’analisi genetica, che ha rivelato un contributo sostanzialmente analogo fra progenitori asiatici e africani. Secondo paradigma era che, subito dopo la colonizzazione umana, i rappresentanti della megafauna malagasy sarebbero stati portati all’estinzione dalla caccia diretta delle prime popolazioni. Uno di questi, il famoso "uccello elefante" o "uccello rock" descritto da Marco Polo sarebbe stato estinto nell’arco di poche centinaia d’anni, sopravvivendo forse solo fino al Diciassettesimo secolo. Uno studio pubblicato giusto ieri su "Science Advances", che reca fra le sue firme quelle della famosa primatologa Patricia Wright, rimette il tutto in discussione. Il ritrovamento di subfossili di Aepyornis maximus nei pressi del Massiccio dell’Isalo (Sud-Ovest del Madagascar) mostra evidenti tracce di macellazione. Il fatto e’ che queste ossa risalgono ad almeno 10.500 anni fa. Cio’ indicherebbe una predatazione nella colonizzazione del Madagascar. Non e’ ancora dato a sapere chi fossero questi primi colonizzatori, anche se e’ verosimile che possano essere dei proto-africani. Resta quindi da ricercare ancora con maggiore impegno tracce di presenze e colonizzazioni umane riconducibili al periodo indicato. Se cio’ fosse effettivamente confermato bisognerebbe nuovamente identificare i processi di estinzione della megafauna, probabilmente in coabitazione con l’uomo per un periodo piu’ lungo di quanto in precedenza ritenuto.

James Hansford, Patricia C. Wright, Armand Rasoamiaramanana, Ventura R. Pérez, Laurie R. Godfrey, David Errickson, Tim Thompson, Samuel T. Turvey. Early Holocene human presence in Madagascar evidenced by exploitation of avian megafauna. Science Advances, 2018; 4 (9): eaat6925 DOI: 10.1126/sciadv.aat6925

Uno scheletro e l’uovo di uccello elefante, Aepyornis sp.

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THE ASTONISHING AMPHIBIANS AND REPTILES OF THE ISALO MASSIF, SW MADAGASCAR

The Isalo Massif, in SW Madagascar, is one of the most interesting and far mysterious areas of Madagascar, despite of the fact that – at the same time – it is also one of the most visited sites. Its peculiar landscapes make it really interesting: around 80 km long, it is featured by a a rough physionomy, a quite dry climate and an intricate system of canyons which makes it really appealing. In the last fifteen years we spent quite a lot of time in investigating the herpetofauna living there. In fact, little was almost known about this massif in terms of biodiversity when, together with my team, began to visit the spectacular sandstone mountains there, in search for amphibians and reptiles. While the high temperature and the sub-desertic profile make quite easy to expect the presence of a rich reptile fauna, comparatively less was hypotesised for amphibians. In reality, the canyon system and the presence of water with permanent and temporary streams and rivers created in the last million years a really interesting site where many species differentiate. Recently we published our final results, obtained by collating former studies carried out wwithin and outside the National Park limits between 2004 and 2014. As a total we reported the presence of 24 amphibians and 47 reptiles. For most of them we provided the molecular data sets. So far we found four described endemic amphibian (Gephyromantis azzurrae, Mantella expectata, Mantidactylus noralottae, and Scaphiophryne gottlebei) and one reptile species (Trachylepis nancycoutuae). Of the taxa listed for Isalo, seven amphibians and six reptiles are new candidate species, and among them at least one amphibian (Mantidactylus sp. aff. multiplicatus Ca65 “Isalo”) and three reptiles (Lygodactylus sp. aff. tuberosus Ca02 “Isalo”, Paroedura sp. aff. bastardi Ca02 “Isalo” and P. sp. aff. bastardi Ca03 “Ilakaka”) are currently known only from Isalo. The importance of the study is – among others – to the collaboration among the authors and with Malagasy institutions, and in the use of an integrative approach, using morphology, colouration, ecology data and museum specimens. This stresses once more how the natural history museums and the collections there preserved are crucial tools to unveil biodiversity traits and define conservation actions.

Cocca W, Rosa GM, Andreone F, Aprea G, Eusebio Bergò P, Mattioli F, Mercurio V, Randrianirina JE, Rosado D, Vences M, Crottini A (2018). The herpetofauna (Amphibia, Crocodylia, Squamata, Testudines) of the Isalo Massif, Southwest Madagascar: combining morphological, molecular and museum data. Salamandra, 54 (3): 178-20.

Mantella expectata, the blue-legged mantella, endemic of the Isalo Massif

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ANIMALI FANTASTICI. LE SALAMANDRE GIGANTI CINESI NON SOLO UNA, MA ADDIRITTURA CINQUE (O OTTO) SPECIE!

Meravigliose e preoccupanti notizie allo stesso tempo dal Pianeta Terra. La salamandra gigante cinese era (una volta) classificata e considerata un’unica specie, sotto il nome scientifico di Andrias davidianus. In un articolo apparso su Current Biology i ricercatori mostrano invece che le popolazioni attualmente esistenti (e in preoccupante pericolo di estinzione) sono in realtà un assemblaggio di specie, cinque o forse addirittura otto! Questo fatto indica una volta di piu’ che la tassonomia degli anfibi e di molti altri animali del nostro mondo biodiverso è ancora in uno stato incompleto e che l’attività’ degli zoologi e tassonomi (anche loro in via di estinzione) e’ ancora estremamente necessaria. Non solo per conoscere le specie che vivono intorno a noi, ma anche – si spera – per proteggerle. Tutte le cinque (o otto) specie cinesi appartenenti al genere Andrias sono minacciate. Non solo per l’alterazione degli habitat e per altre problematiche classiche, ma anche perché le diverse popolazioni, ora riconosciute come specie distinte, sono state traslocate più volte: ritenendo che gli individui appartenessero ad un’unica specie salamandre provenienti da diverse località sono state rilasciate in habitat non propri, con conseguente incremento di fenomeni di ibridazione. Questa suddivisione in 5-8 specie è stata vista come sorprendente, e fino ad ora non riconosciuta a causa del fatto che le salamandre presentano una morfologia simile, mentre in realtà si sarebbero differenziate nel tempo nei tre sistemi fluviali principali e in alcuni altri bacini idrografici, fra loro isolati. Questo isolamento ha probabilmente causato una profonda divergenza ecologica e geografica nonché una conseguente speciazione.

Current Biology, Turvey et al.: "Imminent extinction in the wild of the world’s largest amphibian" http://www.cell.com/current-biology/fulltext/S0960-9822(18)30433-0 , DOI: 10.1016/j.cub.2018.04.005

Andrias davidianus (c) Pinterest (http://www.globalspecies.org/images/a/Andrias_davidianus_1.jpg)

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CHINESE GIANT SALAMANDERS ARE NOT ONE SPECIES, BUT FIVE OR EIGHT!

​Wonderful and worrying news at the same time. The Chinese giant salamanderwas (once) classified and considered just one species, under the scientific name of Andrias davidianus​. In a paper appeared just today on Current Biology shows that in reality this is an assemblage of species, five, or possibly, eight! This just indicates that the taxonomy of amphibians and many other animals in the world is still in a preliminary state and studies are extremely necessary. Not only to know the species living around us, but also, and hopefully, to protect them. All the recognised five species belonging to the genus Andrias from China are threatened and under risk of extinction. Not only for habitat alteration and food collecting, but also because the several populations, now recognised as putative species, have been translocated several times and put in conditions to accelerate hybridisation phenomena. This splitting in 5-8 species has been seen as surprising, and until now unrecognised due to the fact that the salamanders present similar morphology, while in reality they differentiated over the time in at least three major river systems, each splitting in several others. These basins likely caused a deep ecological and geographical divergence and genetical isolation, which led to speciation.

Current Biology, Turvey et al.: “Imminent extinction in the wild of the world’s largest amphibian” http://www.cell.com/current-biology/fulltext/S0960-9822(18)30433-0 , DOI: 10.1016/j.cub.2018.04.005

Andrias davidianus https://www.zoochat.com/community/media/chinese-giant-salamander-andrias-davidianus.255311/

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​30 YEARS OF MADAGASCAR​: CONSERVING AMPHIBIANS OF THE GREAT ISLAND

This year, 2018, it is just 30 years that I come in Madagascar. This is for studying and protecting amphibians and reptiles. The first year I came was just for holidays. It was really funny and interesting to devote myself to the study of a really peculiar herpetofauna! I came from Europe, where I was just studying newts, and Madagascar, with its plethora of frogs, treefrogs, lizards and snakes was a conspicuous heaven. At the same time, conservation problems were already known. Maybe not too "famous" for herps, but more or less on the same lines as those of lemurs and forests. My first visit was at Nosy Mangabe (see photo here attached: happy and with some more hair than now!). After that herp-holiday I repeated my travels to Madagascar so many times that I do not know the exact number of visits. I must say that this country has become my elected nation after Italy. Extraordinarily beautiful but suffering. Forests are disappearing at a very quick rate, people is even poorer and in much worst conditions than in the Eighties. During this period it has been so beautiful to discover many new species of frogs, lizards and snakes in company of colleagues and friends. But even more interesting and – I hope – useful, having acted for the conservation of Malagasy amphibians. With the IUCN SSC Amphibian Specialist Group we made and carried out several projects and formed young Malagasy herpetologists.

Franco Andreone


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WHITE LIPPED TREEFROGS, THE METEOROLOGICAL AMBASSADORS

When I passed in the Vohimana Forest, East Madagascar, I had the exceptional luck to find a considerable number of white-lipped treefogs, Boophis albilabris. This anuran is really particular since, first of all, it is large (up to 81 mm), and then because it shows a very variable colouration, passing from brown to green, with a number of irregular spots. The most interesting thing, or at least one of the most interesting ones, is that during the breeding season males develop pointed tubercles on the back, breast, underside of legs. Part of these tubercles form the so-called nuptial pads, which are used to embrace females during the amplexus. Then, B. albilabris aggregate along streams, especially when cyclones arrive. They are representatives of the so-called "explosive breeders": they mate in just 1-2 nights, when they become visible in hundreds of individuals, after which they disappear as they appeared, like ghosts. During these aggregations they emit low-frequency vocalizations and engage in real battles, with many males around just one female. In this they are somehow similar to what happens in Europe with the common toads Bufo bufo. In Vohimana I found several individuals, and they were really visible. Most likely this was due to the presence/arrival of cyclones, typical meteorological phenomena of the tropical area. In fact, a few days later the strong tropical storm Eliakim stroke Madagascar. Those beautiful Boophis were just ambassadors of its arrival.

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SO BEAUTIFUL MANTELLAS!

I was already in the Vohimana Forest around 30 years ago. It was one of the first raiforests that I ever visited. I was so amazed and so astonished by the beauty of the forest itself, and by the kindness of people living there. At that time the forest was simply called “an’ala”, that in Malagasy just means “the forest”. Under this name I published one of my first papers on the amphibians of Madagascar. In fact, during that visit I found two really beautiful Mantella species, living in syntopy. They were Mantella pulchra and Mantella baroni. At that time the ultimate and correct Latin name of pulchra was not known, and it was named as Mantella cowani pulchra. These two species lived (and still live) together and have very similar colourations. Incidentally they are both toxic, but they belong to two different phylogenettic clusters and are not so closely related. Mantella baroni has sharp colouration of the back, and scattered blue spots on the belly. Mantella pulchra has a much golden head, has a horse-shoe shaped throat bluish belly and reddish marks on the underside of the thighs. I assumed, in my scientific naivity, that they were a good example of Müllerian mimicry. Both toxic and with similar renforcing colouration. It has been with a sort of nostalgy that I visited again Vohimana (or “an’ala”), and I looked again at Mantella pulchra in the almost untouched habitat there. No, Mantella baroni I did not find it. I heard it but I wasn’t able to spot it (the photo that I put here is from another site “Amalonabe”, not so far). Vohimana appears as a beautiful forest, and is a really nice place where to carry out future herpetological studies and education activities.

 

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