About Me

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Canberra-based naturalist, conservationist, educator since 1980. I’m passionate about the natural world (especially the southern hemisphere), and trying to understand it and to share such understandings. To that aim I’ve written several books (most recently 'Birds in Their Habitats' and 'Australian Bird Names; origins and meanings'), run tours all over Australia, and for the last decade to South America, done a lot of ABC radio work, chaired a government environmental advisory committee and taught many adult education classes – and of course presented this blog, since 2012. I am the recipient of the Australian Natural History Medallion, the Australian Plants Award and most recently a Medal of the Order of Australia for ‘services to conservation and the environment’. I live happily in suburban Duffy with my partner Louise surrounded by a dense native garden and lots of birds.

Thursday, 25 June 2020

Peru's Spectacular Desert Coast; Paracas and the Ballestas Isles

For most of us, there is something truly remarkable about a desert running right to a coastline. It happens on the west coasts of all three southern vegetated continents, but perhaps nowhere as dramatically as in northern Chile and southern Peru, where a thousand kilometres of sea-coast meets the mighty Atacama Desert, the driest unfrozen desert on earth. Except for the occasional river valley, there is no plant life here. A relatively easy way to be introduced to it is around the Paracas Peninsula and small resort town of the same name, just 240km by highway south of Lima. This is about the northern limit of the recognised Atacama, though the very arid coast continues way to the north. (A more 'purist' definition would limit the Atacama to northern Chile.)
Paracas from the air, huddled along the shore with the harsh desert stretching out of sight beyond.
(The tinted windows - of the small plane which took us over the Nazca Lines - have robbed the scene of
its characteristic rusty red.)
The reason the desert is here is the presence of the cold Humboldt Current along the coast. This cold water dramatically (and in some Chilean areas totally) suppresses evaporation. It wells up from the deep and brings with it nutrient-rich waters which support hugely rich marine life (and supports the world's richest human fishery).

For the naturalist there are three main reasons for coming here. Best-known is the wonderful and enigmatic Nazca Lines, the vast geoglyphs, some of which are hundreds of metres across, scattered across some 80km of desert. Many depict recognisable animals, created by laboriously moving red desert pebbles to reveal the pale soil beneath. For more on this marvel of the earth, see here. The other two sites are featured today, both part of the Paracas National Reserve, which is a UNESCO World Heritage Site. Part of the mainland section of the reserve is readily accessible on the coast just out of the town, though most of it is out of reach in the desert expanses. The teeming Ballestas Islands are, obviously, only attainable by boat. 

The National Reserve protects more than 330,000ha of desert, ocean and islands. It was declared in 1975, making it Peru's oldest marine reserve, and has since been expanded significantly. 
Looking across the bay to Paracas with a dense flock of Black Skimmers Rynchops niger and a few
Chilean Flamingos Phoenicopterus chilensis. (And I can't help it if these were in Peru!)
Just because there's no such thing as too many flamingos!
(For more on the South American flamingos see here.)
 A drive along this coastline gives a good introduction to other seabirds too. 
Baird's Sandpiper Calidris bairdii, a tiny wader, breeds in the Arctic and winters in South America.

Elegant Terns Thalasseus elegans also breed in North America (though not as far north as the sandpiper) and escape
the cold in South America. Grey-headed Gulls Chroicocephalus cirrocephalus stay in South America all year round.
(They are also widespread on southern African coasts.)

They really are very handsome gulls; these were hanging out by the hotel pool.
Ruddy Turnstones Arenaria interpres are also migrants, found on most of the world's beaches.
The huge numbers of Peruvian Pelicans Pelecanus thagus give a good idea of the richness of the waters.
At a well-known local site we can walk, which gives a feel of the desert landscape, and see 36 million year old fossil shells by the track.
Turritella woodsi.
The desert flowing into the sea.

A massive salt flat towards the end of the walk.
Snowy Plover Charadrius nivosus, which breeds locally and stays here year-round.
Coastal Miner Geositta peruviana is a much sought-after bird, being found only in coastal Peru.
But an even more memorable part of our stay was the boat trip, about an hour's ride to the three islands of the Islas Ballestas. In terms of sheer numbers of seabirds it was truly remarkable.
Approaching the Islas Ballestas.
The first part of the trip, along the coast, gave another view of the stark desert coastline.
It is hard to come to terms with the fact that this land is too dry for any plants at all to establish themselves.
It also provided a view of the mysterious Paracas Candelabra, a huge 180 metre high geoglyph cut 60cm into the surface of the peninsula and edged with stones, dating back apparently 2200 years to the time of the Paracas culture.
Any speculation as to its original purpose must remain just speculation.
It is a dramatic spectacle however.
But soon the main performance began, and kept going while we were on the water. Unimaginable numbers of seabirds - primarily cormorants and boobies - flew past us constantly, heading for the rich fishing grounds and the safety of the rocky breeding and roosting sites on the Ballesta s. The photos give some concept of the spectacle, but not of the sense of awe as the procession went on and on - we must have watched tens of thousands of birds, especially the handsome Guanay Cormorants, flying past us.

Guanay Cormorants Leucocarbo bougainvillii are big birds, found only on the west coast of
South America. Their breeding colonies supported the vast fertiliser industry, based on guano collecting,
which underpinned Peru's economy for decades in the 19th century.
Unbelievably, over 20 million tons were exported from Peru to Europe and North America from 1848–1875! Sadly they continued extracting all year round, even during breeding, so colonies collapsed. Long before them the Incas had extracted and distributed guano for agriculture; unlike their 19th century counterparts the Inca emperors strictly controlled the harvest and forbade disturbance of the colonies on pain of death. In 1909, Peru set up the State Guano Company to protect the industry and placed guards on colonies to protect them. They walled the colonies and built platforms to increase the breeding area. This enabled continuing extraction, but at a lower level. It is now collected only once a year or so, outside the breeding season. The industry was responsible for the first railway in Peru, and for the large numbers of Chinese Peruvians, whose ancestors came to work at the extraction after convicts, then Indian slaves, were no longer available to be exploited. 
One of the walls built to manage the colonies for guano extraction.
Infrastructure for the guano industry, appreciated by the birds.

Park headquarters on the islands - a lonely posting I'd imagine, but a fascinating one.
It's an imposing lump of a building too!

The crowds of birds on the islands, some nesting, plus the resultant noise and aroma, were breathtaking.

We slowly circumnavigated the islands, admiring the rugged rockscape setting, as well as the stars of the stage.

And finally here are some of the inhabitants from closer up.
Guanay Cormorants and Peruvian Boobies Sula variegata.

After the Guanay Cormorants, the Peruvian Boobies are the most significant guano producers.
They are a big bird, up to 75cm long. Like the Guanay Cormorant they are restricted to the Humboldt Current waters.
Peruvian Pelican Pelecanus thagus. Another South American west coaster and the third most prolific
guano producer, it is closely related to the Brown Pelican from further north in the Americas,
but can be twice its weight.
Blackish Oystercatcher Haematopus ater. Unlike the previous species, this shore-dweller
is found on both coasts of South America.

Belcher's (or Band-tailed) Gulls Larus belcheri, yet another Humboldt's Current specialist.

Humboldt's Penguins Spheniscus humboldti occur from central Chile to northern Peru where they
(along with the Galápagos Penguin) are the world's only tropical penguins.
This is only made possible by the cold Humboldt Current waters.

Inca Terns Larosterna inca, yet another Humboldt Current endemic. I think can it lay
valid claim to being the world's most beautiful tern. They are certainly the most striking.
Likewise I think that Red-legged Cormorants Phalacrocorax gaimardi, here nesting on the Ballestas Islands,
are the loveliest of their family. They are found coastally from the Peruvian tropics to the icy waters of Patagonia.
Sally Lightfoot Crabs Grapsus grapsus are found along the tropical Pacific coasts of the Americas.

South American Sea Lions Otaria flavescens lounge on the islands and haunt the fishing boats in the mainland harbours.
When we can finally travel again, please do seriously consider South America, and Peru should be one of your top priorities. We probably think mostly of the Andes (Machu Picchu, Lake Titicaca) and the Amazon, and with good reason, but there is even more to it than that. Paracas is within easy access of Lima, and along with the Nazca Lines, the Paracas National Reserve and the Ballestas Islands are well worthy of a day or two of your time. I hope this post has helped convince you.

I hope too that you're staying safe and healthy in mind and body in these difficult times.
Thanks for reading.

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Thursday, 11 June 2020

Spinifex; the prickly heart of Australia

Huddled along the moister parts of Australia's shores, most Australians have, inevitably, a limited concept of what most of our country is really like. For instance at least 20% of the entire country is dominated by Mulga acacia woodlands, which is remarkable in that this represents more than 1.5 million square kilometres. People do encounter some of the mulga lands while driving some of the inland highways, but they are less likely to be aware that perhaps another 30% of Australia is dominated by just one genus of grass, the formidable spinifex, or porcupine grasses. (Various authoritative sources vary in the percentage cover, which is fair enough, as 'dominate' is a difficult concept to define accurately.)
Spinifex clumps, Triodia sp., to the horizon and beyond, Great Sandy Desert, Western Australia.
In fact Triodia occurs in every mainland state of Australia, as shown by the records in the admirable Atlas of Living Australia below.
It would seem from this that even 30% is a serious understatement, but the key word is 'dominate'; between 22-33%
of the country has a spinifex cover similar to the Great Sandy Desert scene above,
but vast areas beyond this have some spinifex.
I've mentioned Triodia, but you may recall Plectrachne as another spinifex genus - I do, from my long-ago youth. I always struggled to tell the difference, and fortunately it turns out that in this case it wasn't just me, as Plectrachne has quietly been pushed into a bottom drawer, and all 65 spinifex species (all Australian) are now Triodia. (The 65 comes from the Australian National Botanic Gardens, which is always good enough for me; they also cite the upper figure of 33% of the land dominated by the sharp grasses.)

And just one more confusion to dispose of before we get properly into the prickly, itchy, wonderful world of spinifex. You may also be aware of a genus of grasses which bind coastal sand dunes around Australia, Asia, Africa and the Pacific - indeed they are more familiar to most than Triodia is - confusingly called Spinifex. These are not spinifex as we're discussing it here... Yes, I know, and I'm sorry, but you'll just have to accept it I'm afraid. 
Spinifex hirsutus (probably, but I'm totally quite sure of the species), Jurien Bay, north of Perth.
There's thus a good argument for using the name 'porcupine grass' for Triodia, but 'spinifex' is probably too ingrained for change now I suspect, and that's what I'm going to continue using today. 

Spinifex can dominate on sand plains and dunes, stony plains and rocky hillsides, as the following photos illustrate. The first three are in different parts of the Great Sandy Desert.
Flowering spinifex on deep sandy plains with Melaleuca glomerata.

On gibber plains, comprised of smooth wind-rounded pebbles broken down from the crusts of adjacent low ridges.
Note how pale these spinifex hummocks are; this area was in heavy drought, even by its own arid standards.
Spinifex is extraordinarily adapted to drought, one response being in the unusual nature of the numerous
densely tangled leaves. The fresh blades are green and flat (as in the previous and next pictures),
but after a dry period they become permanently folded; this means that the inner face of the leaf
is protected from desiccation while the outer face becomes dry and brown.

On long red sand dunes, with some tree and shrub cover as well.

On iron-red rocky hillside at Yandinga Gorge, Gawler Ranges, South Australia.

On rocky slopes below mulga on the ridges, Lark Quarry Conservation Park, central Queensland.

Grand views of countless spinifex clumps from the mighty Ormiston Pound walk,
western MacDonnell Ranges, central Australia.
While all spinifex is prickly, it is the desert species which provide a truly ferocious impenetrable barrier. The more northern species, which presumably get some annual rain from the monsoons, tend to be (relatively) softer.
'Soft' Spinifex, probably Triodia microstachya, on the dry plateau above Edith Falls
in Nitmiluk (formerly Katherine Gorge) National Park, near Katherine, Northern Territory.
As the mounds get bigger they expand outwards - in areas where fire hasn't occurred for some time hummocks can be up to two metres high and three metres across. If there's been no fire for over twenty years they start to form rings, as the inner material dies off completely. I assume that part of this process is due to a depletion of nutrients in the soil under the centre of the mound.
Mature Spinifex rings, Calpatanna Waterhole Conservation Park, Eyre Peninsula, South Australia (above)
and Great Sandy Desert (below).

The Australian National Botanic Gardens has developed an impressive
and beautiful 'Red Centre Garden' complete with spinifex rings! However they didn't wait for the clumps
to mature, they simply planted the seedlings in circles! Very neat.
November 2013 above, and 12 months later, below.

The spinifex lands have been fire-managed by people for tens of thousands of years; the grass is rich in resins and it burns fiercely and regrows both from seeds in the soil and shoots from the plant base.
Burning spinifex, Uluru National Park.
I have read suggestions that the 'natural' fire regime may be only five years, but we also know
that mature spinifex (ie more than twenty years old) is essential habitat.

A study published in 2014 suggests that mass flowering is preceded by an unusually wet 12 months, and is followed by mass seeding which may help swamp seed predators (including ants and birds) and prevent them carrying away the whole crop. Flower heads tower over the spinifex hummocks.
Flowering spinifex, Lasseter Highway, central Australia...

... and near Ewaninga, north of Alice Springs, above and below.

The viciously-spined spinifex hummocks form an impregnable fortress for small animals which can dive into them, thwarting larger predators including us. Within the mound the leaves die (no point in maintaining leaves which can't photosynthesise, because they aren't receiving sunlight) and there is a tangle of stems. An idea of the richness of the spinifex world, an often apparently lifeless landscape, can be gained by examining the labyrinth of tracks around the spinifex in the morning.
While we were warm in our swags, the frosty night was well and truly awake!
Here are a few more spinifex dwellers.
Central Military Dragon Ctenophorus isolepis, Great Sandy Desert; it is rarely found away from spinifex.

Panther (or Leopard) Skink Ctenotus pantherinus, Ormiston Pound, Western MacDonnell Ranges.

The dense spinifex around the Ochre Pits, Western MacDonnells, is a noted site for the
widespread but elusive Rufous-crowned Emuwren, Australia's smallest bird, weighing just six grams!
I first saw them there, but it was many years before I managed my only photo of them.
They are only ever found where there is mature, unburnt spinifex.
Male Rufous-crowned Emuwren, Great Sandy Desert.
He emerged briefly from his spinifex castle to inspect us.
A lovely Spinifex Pigeon Geophaps plumifera, another species very closely associated with spinifex.
Bladensburg NP, central Queensland.
Spinifex takes up silicon from the soil to reinforce its spiny tips and harden of the leaves; the silicon particles can break off in a wound and become infected. As a result, uniquely among major world grasslands, spinifex is not grazed by large mammals. The only one which can do so is the Euro Macropus robustus. This diet is very low in nitrogen, essential for the necessary gut bacteria; the Euro compensates by recycling nitrogen from urea.
Euro; above (with Spinifex Pigeons) Bladensburg NP, central Queensland;
below, near Broken Hill.
The real spinifex grazers however are termites; the triangle of spinifex, termites and lizards in the Australian deserts has been likened to the great African grasslands, antelopes and lions (etc). The mass of termites per hectare in the central deserts is greater than that of all other animals. Each spinifex clump has a tunnel opening beneath its centre. In one small area near Alice Springs there are 50 termite species. In turn this supports the world’s greatest concentration and diversity of lizards.

The great termite mounds of the tropical Australian savannahs are famed, but those of the spinifex country can be equally impressive. Here are some examples.
Plenty Highway, north-east of Alice Springs.
Barkley Highway, north-eastern Northern Territory.
Great Sandy Desert, above and below.
Covered termite runway between spinifex clumps, Great Sandy Desert.
Termites don't like to be exposed to hot and dry air.
Finally, before we return to our lives which are probably mostly very distant from the wonderful spinifex country (and writing this has given me a great longing to get back out there as soon as we can travel freely again), let us just enjoy some of the beauty of spinifex.
Late afternoon, Palm Valley, central Australia.
Sand patterns from spinifex flowers blowing in the wind, Great Sandy Desert.
Kata Tjuta sunset through the spinifex flowers, above and below.

Sunset through spinifex flowers, Great Sandy Desert.
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