Wednesday, 29 June 2016

San Pedro de Atacama; an astonishing part of the world. Part 2, desert lakes

In my last posting I introduced some of the spectacular Atacama Desert landscapes in the far north of Chile, in the San Pedro de Atacama area; if you missed that you might like to have a quick look, as it sets the scene for today's instalment. In it I intimated that while wildlife isn't always obvious in this most arid of earth's non-polar areas, there are hot spots (some of which are actually very cold!), two of which I'd like to share with you today. Both, unsurprisingly, involve water but that aside they are as dramatically different as one could imagine.

The first is high in the Andes, some 110km south-east of San Pedro and at 4,100 metres above sea level (masl) is 1700 metres higher. The climb into the Andes is gradual but, as we approach our goal, which is Laguna Miscanti, the snowy peaks start to surround us and there is more vegetation (though still sparse) from the limited rainfall that finds its way over the peaks from the west. 
Tussock grassland at 3,900masl, between the village of Socaire and Laguna Miscanti.
Small perched high lakes start to appear, giving us a taste of what is to come.
Looking out over the plains of the Atacama from where we've climbed.
This little lake is probably formed by a dam of material left behind by a retreating glacier
after the last glaciation.
While San Pedro's 2400masl doesn't bother most people, anything over 4000 metres is a challenge for most of us; the short walk from the car park to the lake will be a slow one, and is likely to be through a snowy landscape. It is also one that you won't want to miss - Laguna Miscanti is almost impossibly beautiful.
Laguna Miscanti, above and below; to the left is Cerro Miscanti.

The near-freezing waters nonetheless support bird life.
Andean Gulls Larus (or Chroicocephalus) serranus live only in the high Andes, even breeding up there.
Horned Coots Fulica cornuta are also high Andes specialists and are not common, but live and breed on Laguna Miscanti. They carry pebbles out into the water where they drop them to construct huge artificial islands on which they build their nest of vegetation. On the day we were there it was very windy and the track near the lake shore was closed, so I foolishly opted not to take distant photos in the expectation that I'd get other opportunities. I didn't. 

However there were small passerines around, including species you won't readily see elsewhere.
Puna Miner Geositta punensis, Laguna Miscanti, one of a group of South American tyrant flycatchers
which nest in burrows (including those dug by rodents). This species is limited to a small area
of the central Andes above 3000masl.

Rufous-naped Ground-tyrant Muscisaxicola rufivertex.Another ground-foraging tyrant flycatcher of the high Andes.
And of course there are predators.
Culpeo, or Andean Fox, Lycalopex culpaeus, found throughout the entire length of the Andes.
To reach our other lake and an entirely different experience we must backtrack towards San Pedro and then head west off the bitumen into a section of Los Flamencos National Park - and yes, flamenco does mean flamingo! By the time we reach our destination and walk out on raised paths through the apparently forbidding Laguna Chaxa, we have descended 1800 metres to 2300masl, slightly lower than San Pedro. The approach does not suggest that a lake system is near.
Feral Donkeys; their ability to make a living here is remarkable, but one must hope that numbers are low.
Laguna Chaxa is in the Salar de Atacama, the world's third largest salt pan (after nearby Uyuni in Bolivia, and Death Valley in the US). 
Salt and mud stretching into the distance; not a promising landscape for life, but it is abundant here.
Laguna Chaxa, with the ever-present Andes looming. Flamingos and other wading birds thrive in hyper-saline
lakes which, counter-intuitively, support numerous microscopic organisms, especially diatoms,
and larger prey such as brine shrimps.
The water flows underground from the Andes and comes to the surface in such lagoons, which have no outflow. Most famous of the wildlife are the three flamingo species which breed there - the more widespread Chilean Flamingo Phoenicopterus chilensis and the two more restricted high Andes species, Andean Phoenicoparrus andinus (the rarest flamingo species) and Puna Flamingo Phoenicoparrus jamesi. (For more on the American flamingos, see here.)
Andean Flamingo showing typical flamingo feeding style - bill upside down, using the fleshy tongue covered
with protuberances to pump water past similar protuberances on the bill to extract food from mud.
This bird has been banded - probably while a nestling - as part of ongoing studies.
 And another of Andean Flamingos being aesthetic, which they're very good at.
Other high Andean waders are present too - again these are birds you won't readily see elsewhere, and several of these were new to me.
Andean Avocets Recurvirostra andina; yet another restricted range Andean endemic (by far the most restricted
of the four avocet species), breeding above 3,500masl. Like the others its curiously upturned awl-shaped bill
is swept from side to side, snapping shut on small animals.
Puna Plover Charadrius alticola; the species name 'high dweller' says it all.
It has a very similar central Andean range to the Andean Avocet, living mostly between
3,000 and 4,500 masl.
Baird's Sandpiper Calidris bairdii on the other hand has a huge range, breeding in the
Arctic from Greenland to Siberia, and migrating to South America where it can be
found from northern Peru to Tierra del Fuego, from the mountains to the coast.
One of the most conspicuous inhabitants however - apart from the vast swarms of flies on the water  surface, though they didn't bother us - is Fabian's Lizard Liolaemus fabiani, found in all the world only in the Salar de Atacama. It was only collected in 1981 and described in 1983; the name has nothing to do with the social change movement, but everything to do with Chilean herpetologist Fabián Jaksic. I imagine that prior to this it was assumed that they belonged another of the many species of Liolaemus - they could hardly have been overlooked!

I was so taken with these salt specialists that I can't help sharing several photos of them with you.

I am astounded that a lizard could be so at home in such hyper-saline conditions.

Here you get some idea of the abundance of the flies which presumably lead to the abundance
of the lizards. They keep their distance as the lizards pass by.
I am assuming that these brightly coloured individuals (above and below)
are males, but I can't find much information on the species.

Which pretty much brings us to the end of this visit to this fascinating part of one of the world's great, and most fascinating, deserts. I hope you can get there yourself one day, but meantime I trust that this can whet your appetite. And of course if you have been, I hope that this brings back good memories.



Flabmeister said...

I wondered how long the lizard was (primarily to see if it was a small lizard or if they were huge flies). From Liolaemus fabiani, a New Species of Lizard from Northern Chile (Reptilia: Iguanidae); José L. Yáñez and Herman Núñez it seems the lizard is quite small - about 7cm or 3" in old money.

An interesting part of this process is that the cited paper is part of JSTOR which now allows you to register and read (a small number of papers at once) for free on line rather than paying $4 per page!


Ian Fraser said...

I fully endorse your comments about JSTOR, a most valuable resource. However my memory of the lizards is that they were about twice that length; my memory can easily be faulty however!

Flabmeister said...

Head and body are 7cm. The tail adds another 7cm. On that basis your memory is probably spot on and my powers of expression have atrophied due to cold weather.