The Elephant Birds of Madagascar 17Th Century
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NEWS & VIEWS offered for (illegal) sale as curios. A little- The Arabian Nights. The rokh, so the story known fact about the eggs is that until as goes, was an eagle-like bird so enormous recently as the mid-19th century they were that it preyed on elephants. There is good used by humans to transport liquids. There reason to suspect that this fanciful tale enormous, is something distinctly surreal about the originated from birds that occurred on notion of a gigantic egg, several centuries Madagascar, and elephant birds have long old, being used as a water container by a been seen as the obvious candidates. thirsty Malagasy traveller. But Steven Goodman and William enigmatic & extinct All the elephant birds were extinct by the Jungers have recently pointed out that The elephant birds of Madagascar 17th century. A French governor stationed another extinct Malagasy bird could in Madagascar during the mid-1600s men- have contributed to the origin of this n the mid-1800s three huge eggs Aepyornis and three Mullerornis species, mainly in forests, since the spiny vegeta- tioned ostrich-like birds that occurred in legend. Belonging to the same genus and were transported from Madagas- although the actual numbers remain un- tion typical of Madagascar’s arid regions remote regions, but he did not see them WIKIMEDIA COMMONS (2) approxi mately the same size as Africa’s car to France, and the Western clear. This uncertainty reflects the fact generally is characterised by other, iso- at first hand. There is no way of knowing Aepyornis skull on display in the National Crowned Eagle, Stephanoaetus mahery worldI came to learn that this island had that all these species were described topically distinct, photosynthetic path- whether the birds still existed at that time Museum of Natural History, Paris. was probably a specialised lemur hunter. once been home to giant birds. Named from the morphological traits of bones ways. It has been proposed by several or if his accounts were based on already Perhaps sailors’ tales of a large and for- Aepyornis maximus by French natural- and eggshell remains. Until molecular researchers that elephant birds were im- vanished creatures that persisted only in Another possible cause concerns natu- midable forest eagle became intertwined ist Etienne Geoffroy Saint-Hilaire, the techniques are used to analyse extracted portant seed dispersers for a number of the oral traditions of local people. ral climate change. There is evidence that with accounts of the gigantic elephant species that laid the eggs was the larg- DNA, it will be almost impossible to rule Malagasy trees, including the six species The reasons for the elephant birds’ southern Madagascar, which appears to birds and the chimera that emerged was est bird known to have existed in recent out scenarios such as two ‘species’ in re- of baobabs endemic to the island. demise are far from clear. Human pres- have been one of the strongholds of the the terrifying raptor of Arabian legend. millennia, standing three to four metres ality being the males and females of one ence in Madagascar dates back at least elephant birds, has become substantially ANDREW McKECHNIE in height and weighing about 450 kilo- sexually dimorphic species, as happened THE EGGS OF A. MAXIMUS 2 000 years, and possibly to a significantly drier within the past thousand years. grams, more than the combined weight in the case of New Zealand’s moas. WERE TRULY ENORMOUS, earlier date. Elephant birds and humans Many animals associated with moist References of four ostriches. Madagascar in the age of the elephant EACH WITH A VOLUME thus co-existed for at least the better part of habitats are known from sub-fossil sites Clarke, S.J. et al. 2006. ‘The amino acid and Other species of elephant birds have birds was a very different place to Mada- two millennia and no unequivocal archae- in the area but no longer occur there. It stable isotope biogeochemistry of elephant subsequently been described. Current gascar today. The island’s forests were EQUIVALENT TO ABOUT ological evidence for human predation of may well be that habitat changes driven bird (Aepyornis) eggshells from southern thinking is that there were probably four home to an incredible variety of extinct SEVEN OSTRICH EGGS the birds has been found. This suggests by this shift in climate contributed to the Madagascar.’ Quaternary Science Reviews, mammals, among them gorilla-sized le- that the overkill hypothesis, so often in- extinction of the birds. 25: 2343‒2356. murs and aye-ayes four times larger than The Clarke et al. paper also presented voked to explain megafaunal extinctions Elephant birds have been Goodman, S.M. and Jungers, W.L. 2014. the single extant species. Sloth-lemurs information about oxygen isotopes and that coincided with the arrival of humans, mooted as the origin of the Extinct Madagascar: picturing the island’s moved along the undersides of branches the data that emerged are relevant to probably does not explain the disappear- legend of the rokh, the giant past. University of Chicago Press, Chicago in a manner akin to their South Amer- reconstructing the elephant birds’ ecol- ance of Madagascar’s giant ratites. bird in Sindbad’s adventures in and London. ican namesakes. Dwarf hippopotami ogy. The stable oxygen isotope signatures wallowed in lakes and rivers, and bizarre of eggshells reveal that elephant birds creatures known as bibymalagasias, or drank regularly from groundwater-fed Madagascar aardvarks, fed on ants and ponds, wetlands and lakes in coastal are- termites. as of southern Madagascar and were thus Almost nothing is known about the probably associated with habitats in the natural history of elephant birds, but sev- vicinity of such water sources. eral inferences can be drawn from bio- One aspect of elephant bird ecology chemical analyses of their remains. The that can be inferred without resorting to most significant recent study appeared biochemical analysis is that some species in 2006, when Simon Clarke and his col- nested colonially. At the southern tip of leagues reported that the stable carbon Madagascar, coastal dune sites with ex- isotope signatures of Aepyornis eggshells ceptionally high densities of A. maximus from southern Madagascar are consistent eggshell fragments reveal that these gi- Aepyornis maximus with the birds feeding on plants with C3 ants nested in large colonies, with breed- photosynthesis. This reveals that elephant ing sites possibly being used by many birds fed mainly on trees and shrubs, and generations. To this day, intact eggs are grasses and succulent plants represented occasionally found in this area. only a small part of their diet. The eggs of A. maximus were truly enor- The C3-dominated diet further sug- mous, each with a volume equivalent to gests that the elephant birds foraged about seven ostrich eggs. Many visitors to modern-day Madagascar will have en- Common Ostrich WIKIPEDIA/ Size comparison between the giant egg of the countered these eggs, which have been Homo sapiens Struthio camelus HOUSTON MUSEUM OF NatURAL SCIENCE elephant bird and that of the Common Ostrich. pieced together from fragments and are 10 AFRICAN BIRDLIFE JANUARY/FEBRUARY 2016 NEWS & VIEWS 11 NEWS & VIEWS 2nd W more than just 2nd World Seabird Confer World Seabird Conference ence Seabirds: Global Ocean Sentinels October 26 – 30, 2015 C making waves ape Town, South Africa hot air nterested in how seabirds navigate at For me, one of the highlights was the Scientists have long known that birds are feeling the heat due to sea, how young seabirds learn their suite of findings from the Oxford Navi- climate change. However, a new study of a dozen affected species in trade or how an increasingly stormy gation Group. They used a clock-shift the Western Cape suggests their decline is more complex than previ- planetI is going to affect seabirds? These experiment to show that breeding Manx Hosted by African World Seabird Union Seabird ously thought – and in some cases more serious. were just some of the topics explored at Shearwaters use a sun compass to orien- Group the Second World Seabird Conference tate at sea, but also follow visual landmarks ccording to the study, published comparison of data contained in the two (WSC), which took place in Cape Town once they are in sight of land. Previous in Conservation Physiology and Southern Africa Bird Atlas (SABAP) sur- in October 2015 under the auspices of work on shearwaters has confirmed the their parents and many do not survive carried out by scientists from the veys conducted 15 years apart. This data the World Seabird Union. importance of scent for homing. the first few months, when they seldom APercy FitzPatrick Institute (University was matched with climate data for the The WSC brand was established in 2010, Many studies used the latest tracking dive to more than 100 metres. Those of Cape Town) and the Nelson Mandela comparative period, as well as with physio- when the Pacific Seabird Group hosted technology, but have moved beyond sim- that make it through this period show Metropolitan University in Port Elizabeth, logical data. A key aspect of the study is a the first meeting in Canada. It also saw ply documenting migration routes and an increase in dive depth and duration, there could be several reasons why birds comparison of climate and bird population 21 regional seabird organisations joining are now attempting to understand how reaching depths of 250 metres (but still are being negatively affected by human- data with the heat response – or ‘thermal forces to form the World Seabird Union individuals behave. The general pattern less than adults). By comparison, adult made climate change. tolerance’ – of each bird species. In this to promote seabird research, management emerging for most species is that individu- Greater Frigatebirds return to their col- They suggest that, contrary to expecta- way researchers assessed to what extent DIONNE MILES and conservation worldwide.