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I've been a Canberran since moving here from Adelaide on the first day of 1980. I now live in suburban Duffy with my partner Louise Maher, ABC 666 radio and on-line journalist. Among my early memories is following Sleepy Lizards (Shinglebacks) around the paddocks north of Adelaide, guarded by the faithful bull terrier. I have always been passionate about the natural world, trying to understand how it works, how the nature of Australia came to be, and sharing those understandings. My especial passions are birds, orchids and mammals. For much of my life I have been a full-time naturalist, running bush tours, writing books etc, doing consultancies, presenting a regular radio slot on local ABC, chairing a government environment advisory committee and running adult education classes. Recently I have eased back somewhat, but am still writing, teaching, doing some radio work and running overseas tours - as part of my fascination with our Gondwanan origins I've been running tours to South America for the past decade. I was awarded the Australian Plants Society Award in 2001 and the Australian Natural History Medallion in 2006, both for services to education and conservation.

Wednesday, 21 October 2015

American Camels

I think some people are surprised to realise that there are camels in America. Even more, I suspect, are taken aback to learn that camels actually arose in North America, some 45 million years ago. Over their long history in that continent - which ended only very recently - some 90 camelid species in 35 genera arose, from tiny delicate gazelle-like animals to huge six metre high giraffe-like camels. Some six to seven million years ago one of the larger of these species crossed the then dry Bering Strait into Asia; its descendants eventually reached Spain. Two descendant species still live, both in the genus Camelus, inhabiting some of the harshest lands on earth. The Bactrian Camel (C. bactrianus) adapted to the summer-baking and winter-freezing stony deserts of the central Asian steppes, while the Dromedary (C. dromedarius) settled in the hot sandy deserts of south-western Asia and north Africa. Both were domesticated between four and six thousand years ago (Bactrians first), to the extent that there are now no wild Dromedaries in their home range, and very few wild Bactrians, though there are nearly 20 million domestic Dromedaries and about a million domestic Bactrians.
Feral Dromedary, Musgrave Ranges, central Australia.
The ancestors of inland Australia's feral camel population - the only wild Dromedaries in the world -
were brought here from British India as pack animals in the nineteenth century.
There are at least 600,000 of them, representing a serious environmental problem, especially to scarce water sources.
Probably less than a thousand wild Bactrian Camels survive, deep in the Gobi Desert.
Recent genetic work suggests that domestic Bactrians have changed enough that the wild animals
merit different species status, as C. ferus.
Photo courtesy of National Geographic.
More recently - some three million years ago - another opportunity arose for the North American camels to expand their range. This was the collision of South America with the North, providing major two-way access between the continents via the Panamanian Land Bridge. 

Two species derived from the invasion. Widespread in open habitats of the continent was the Guanaco Lama guanicoe; more specialised is the much smaller and more delicate-looking Vicuña Vicugna vicugna which is limited to the high northern Andes, over 3500 metres above sea level.

 
Guanacos, Torres del Paine NP, Chilean Patagonia.

Vicuña near Chivay, southern Peruvian Andes.

It has been estimated that 50 million Guanacos once roamed the plains and mountains, but now perhaps 1% of that number survive, mostly in the far south; only in the southern tip of Argentina do they maintain a presence in the plains. Vicuña numbers are slightly lower than that, but they were never as numerous and numbers actually appear to be increasing. However many, even most, wild Vicuña populations are heavily managed for regular shearing, with some even kept permanently in large corrals, which prevent natural gene flow. A second domestication of most of the remaining wild Vicuñas may be underway.

The Guanaco hot-spot is Torres del Paine, where large herds are still ubiquitous. Further north things are dire for them. The northern sub-species L. g. casilensis numbers less than 4000 animals now, in southern Peru and northen Chile.
Northern Guanacos, above and below, Atacama Desert near San Pedro, northern Chile.

These harsh high deserts support both species.
Vicuñas, Aguada Blanca National Reserve, southern Peru.
Guanacos live either in family groups - a male defending several females and offspring, or as troops of males waiting their chance, sometimes for years, or as solitary mature males, hanging around the periphery of territories, challenging the incumbent males. 

(All subsequent Guanaco photos were taken in Torres del Paine NP.)
Guanaco herd, females and young.
The single young - called chulengos - are born in summer after an 11 month gestation, weighing up to 15kg, a sixth of adult weight. They are suckled for 15 months; all these characteristics are adaptations to a harsh climate. Nonetheless mortality is high (up to 15% in the first 10 days in Torres del Paine), the main cause being Puma predation.
Chulengos on the park boundary - the adults easily leap the fence (below).

Fresh Puma-killed chulengo.
Males will fight viciously for hours with intruders, with exhausting chases; just when the struggle seems to be over with one party completely beaten, the tables can turn in an instant and it all starts again.



Despite these dramatic scenes, when we moved on after nearly an hour
neither party seemed to have any ascendancy.
As with their Old World relatives, both species were domesticated early - thousands of years ago. Both of the domesticated animals have evolved so far from their wild ancestors that they are now regarded as separate species. Guanacos gave rise to Llamas (Lama glama) and Vicuñas to Alpacas (Vicugna pacos). The much larger Llamas were developed as pack animals - huge caravans of Llamas traversed the vast Inca empire, carrying goods for hundreds of kilometres. Alpacas on the other hand were bred to be producers of valuable fibre. Large herds of both roam the high Andes, usually in the care of shepherds.

Llamas, Machu Picchu, Peru.

Alpacas (and Andean Geese) near Chivay, southern Peruvian Andes.

Mixed mob of Llamas and Alpacas with young shepherd, near Chivay, southern Peruvian Andes.
The Llamas have nearly bare faces.
The coloured ear tags, denoting ownership, are a part of a very old tradition.
And the ancestors of all these animals, back in North America? They survived until very recently, perhaps only 15,000 years ago, during the last glaciation. Savage climate change alongside hunting pressures and perhaps changed fire regimes from newly arrived humans probably interacted to eliminate them, along with many other large grazing animals, including several South American camel species.

So now, if you want to see wild camels in the land they evolved in, you're going to have to go to South America. And really, that's not a hardship...


BACK ON WEDNESDAY

1 comment:

Flabmeister said...

Fascinating as always. I will confess to being a bit anxious about where llamas and alpacas fitted in, before my concerns were erased in the latter stages!

Your reference to the extinct mega-camels in North America caused me to recall a recent conversation with a paleontologist who commented that there used to be megafauna everywhere, but they have died out everywhere except Africa!

Martin