Monthly Archives: September 2013

Kimberley Biota

In my last post I described the incredible geology of the Kimberley.  This time around I want to focus on the creatures creeping along, and soaring above the landscape, and about the greenery thriving in the most unlikely places.  A favorite of mine has to be the iconic boab trees.  Leafless this time of year, the massive pot-bellied trunks appear stuck in the dry countryside like hulking organic Buddha statues.  They are known as upside-down trees because the branches look likea bare root system reaching up to the sky much of the year.  In fact, the tree’s anchor is a single taproot searching the dry soil for a deep water source.  I have seen boab trees that would take at least 12 people to reach around the beer-belly of a trunk.  Their closest relatives occur on Madagascar where there are six species and one variety more can be found throughout all of Africa.  I might have to start a checklist and try to see all eightboab species around the world.  It’s as good an excuse to travel as any!

Boab

A boab tree without its leaves during the dry season.

Boab & Me

How many people would it take to link arms around this boab?

A tough and wiry grass known as Spinifex carpets much of the Kimberley.  The first couple of days here I walked across the stone country and my legs accumulated a fibrous, gummy coating from the grass and man, did that itch and burn after a freshwater shower in the evening.  I learned pretty quickly not to shave my legs right before walking the narrow grass-lined tracks around here.  As aggressive as I find the grass, it’s a wonderful haven for all kinds of insects and small lizards that can hide in the curly, matted, and well protected “forest” of reed-like grass blades.  So far, I’ve encountered a highly poisonous brown snake, grasshoppers, spiders and tiny lizards living in the Spinifex.  If I had time to sit and observe these small oases, I’m sure far more critters would reveal their hiding places.

Animal_Lizard

Little lizards like this live in the Spinifex grass and venture out to prey on insects from time to time.

Unlike the microcosm of animals hiding away in grassy clumps, termites in the Kimberley live right out in the open.  Their massive mounds and towering teepees speckle the vast savannas like small-scale cities – which in fact, they basically are – being highly organized colonies with a queen laying thousands of eggs each day.  The termites are white and related more closely to cockroaches than the ants they resemble.  They thrive by breaking down cellulose in wood.  By turning this otherwise overlooked resource into the protein in their bodies, they nourish a huge array of animals including echidnas, reptiles, birds and bandicoots.

Animal_Termite Mound

A massive termite mound like the many thousands that are scattered around the Kimberley region.

While some reptiles enjoy snacking on tiny termites, others require a slightly larger meal.  The Kimberley is renown for it’s healthy crocodile populations, both fresh and saltwater varieties.  We come across them basking in the sunlight on just about every available muddy bank and tidal creek.  I love watching their cat-like pupils slide behind thin-skinned nictitating membranes each time they blink.  They truly embody the dinosaurs they are descended from – ancient predators instructed by instinct alone – they are the unpredictable, fear inducing kings and queens of their realm.

Animal_croc

Leaving the terrestrial world far below, raptors of many shapes, colors and varieties pass overhead tracing the contours of the landscape with the single black dot of their shadow.  The big, solitary birds of prey can be Wedge-tailed Eagles, White-bellied Sea Eagles, fish-eating Ospreys, or the stunning russet red Brahminy Kites.  Flocking hawks are generally Black or Whistling Kites – slightly smaller in size and soaring up high with the air of a menacing biker gang on the wing – they circle local parks ready to snatch a tuna wrap right out of the hand of an unsuspecting picnicker.  This actually happened to someone during lunch the other day.  Watch out for ominous gangs of Kites if you ever visit the Kimberley!

An Osprey Nest built on top of stone in the middle of a salt pan environment.

An Osprey Nest built on top of stone in the middle of a salt pan environment.

Foundations of the Kimberley Coast

Imagine red sandstone rock cliffs plunging into fecund green and blue seas.  Picture rays of light from a low sun striking this rock and setting it on fire in its glow.  Now envision sparse and tenacious trees standing out on this landscape – their green foliage lit up in the sunlight, and pale, or dark tree trunks in stark contrast to the ruddy sandstone rippled with hues of purple, pale blue, and smoky gray.   If you can do all this, you might have a dim image in your mind of the stunning Kimberley Coast off northwest Australia. 

Rock and Veg

While appearing barren and stark, the shores hold a surprising diversity of life forms from shorebirds to crocodiles, and from termites to humpback whales – but more on this later.  For now I want to focus on the rocks themselves and the way they have been sculpted over millennia by water both freshwater rains and saltwater tides.

Rock_Landscape 2

I am here in the dry season and the waterfalls are mere trickles making the rock faces slick and black in a few places.  While it would be incredible to see this region with the cascades in full swing, I’m content to experience the persistent sunshine and skeleton bare shorelines of the dry season.

Rock_View

Eons of sand, silt, and mud have been deposited from ancient coral reefs, rivers, and beaches to slowly build up the famous layered sandstone and limestone of the Kimberley.  The primeval inertia of tectonic plates colliding has forced the stone up into vertical walls in places.

Rock_Syncline

In other spots, the cliffs reveal steep waves of scrunched up rock; a testimony to the thickness of the layered rock and the forces that have changed its appearance forever.

Rock_Landscape

At the Horizontal Waterfalls, a soft and vertical siltstone layer has eroded away thanks to the force of tides moving through a series on long, skinny bays.  Twice daily all the water of the ocean on one side of Talbot Bay must pass through two eroded siltstone gaps to the other side of the bay. The gaps are at least 60 m deep and water rushes through in one direction on an ebbing tide, and then in the opposite direction on the flooding tide.

Horizontal Falls_2nd Gap

With our Zodiacs we were able to approach the larger gap and witness first-hand the Horizontal Fall.  The force of the tides ripping through the gap pushed our small craft and urged us around with each turn of the tiller.

Horizontal Falls_1st Gap

Another geologic highlight so far has been cruising up into the King George River – truly it is an estuary hedged in by sheer vertical sandstone slabs and cliff faces.  I was able to hike to the top of the vast waterfall here, and although the falls were bone dry, the views looking back over the river were stunning.  I enjoyed having a chance to see the bare rock edges and envisioning the slow erosion of the stone as falling wet season waters carve out the river’s canyon.

Rock_View 2

In another couple of days I’ll be back to exploring the Kimberley coast via Zodiac and on foot, and will write again with an insight into some of the fascinating vegetation and wildlife that’s indigenous to this remote and isolated region.  Thanks for reading!