Shingleback Crossing - Stop and Lend a Hand

Road kill is always on my mind when I travel in Australia.  More often than not, I see dead or maimed animals along the road verge; the by-product of modern, high speed motor transport.  The further one travels away from the city limits the more prolific road kill can become.  

LEFT:  A shingleback lizard is given a helping hand to cross a busy highway in South Australia (click for larger view).

On a recent trip to South Australia, the time taken to travel between points was longer than normal.  The culprit that was slowing my travel was a relatively small slow moving animal protected by a heavy armour of interlocking  pine cone-looking scales; it was the Shingleback Lizard (Tiliqua rugosa), often referred to as the pinecone or stumpy-tailed lizard.  

It appeared that every time I gathered driving speed, I’d witness yet another "pinecone" crossing the road.  Sometimes they would amble quite briskly across the centre-line, only to stop and raise their head, sensing the vibrations of an approaching vehicle, before doubling back into the direct line of the vehicle.  I was stopping several times within a few kilometres, to dismount and rescue these ancient-looking dinosaurian-looking reptiles.

Brief Natural History

Shingleback Lizards, the largest lizard of the Skink family, live alone for most of the year; however, between September and November reunite as monogamous pairs.  Shinglebacks are often seen crossing roads in pairs, with the male following the female; the same pairs may unite every year during the mating season.  With the life expectancy of a shingleback reaching approximately 20 years and the fact that they are monogamous, it’s important that individual lizards are not squashed unnecessarily into the bitumen by uncaring motorists.

Unique Facts - say no to"SEX" with your brother

One very interesting aspect of shingleback reproduction is the ability of the lizards to discriminate between kin and non-kin, even after being separated from their mothers after birth.  This observation has been scientifically tested by observing that they preferentially direct attention and tongue flicks to related over non-related individuals (Main & Bull, 1996).  The mechanism for this unusual ability is unknown, but probably involves olfactory cues.  Whatever the mechanism, not reproducing with your “brother or sister” has obvious genetic benefits and cannot be dismissed.

Reptiles are ectothermic meaning they derive their body warmth directly from the environment.  This is one reason why you never see reptiles during the winter months or on cold overcast days.  It's also another reason that you often see reptiles sunning themselves on the road verge; the bitumen is warm.  To aid in warming itself, the shingleback has the ability to arc and flatten its body extending its scales so that they present a greater surface area towards the sun.  An added benefit to this solar warming is defence; flattening itself the shingleback can appear larger in size.  The posture and size also mimics a highly venomous snake called the death adder.

LEFT: A meeting and mutual respect; a shingleback lizard (Tiliqua rugosa) is carefully carried across the highway (click for larger view).

Foraging Strategies and Navigation

Foraging strategies change throughout the year among sexes.  During the two months before mating males use a time-maximization strategy, while females use an energy- maximization strategy.  During mating when lizards are paired, the male eats significantly less than the female whose eating habits do not alter.  During this time the male maintains a distance of a few centimeters behind the female.  This behavior when paired, presumably suggests that males are on the alert for rival males.  Bull & Pamula (1998) discovered that females can detect danger far more quickly when paired than when alone, and when paired the female earlier when the male is feeding.  They suggested this behavior maybe an adaptation for identifying large predators, such as dingoes, feral cats and wedge-tailed eagles when plant food is only available at exposed locations.

A study by Freake (2001) found that the lizard can use celestial cues as a navigational strategy to return to its home range. It detects these cues using its parietal eye, perhaps functioning as a celestial compass.  

Not a Klutz

If you have read this far, you’ll realize that the Shingleback is not just a slow-moving armoured klutz, but a marvel of evolutionary design.  Therefore, the next time you see a "pinecone" crossing the road, give way to the shingleback.  Better still, stop your vehicle and give the lizard a helping hand.

Yellow-footed Rock Wallabies (Petrogale xanthopus) - South Australia

A 600 km trip north of Kangaroo Island placed me at a favoured location to photograph Yellow-footed Rock Wallabies (Petrogale xanthopus).  I’ve been coming to this location for several years and have been excited at watching the population of these threatened small marsupials slowing increasing in number.  

LEFT:  A Yellow Foot, it's spectacular and distinctive fluffed tail showing, sits on a rock in-between feeding.

Hunted by the early settlers for their ornate yellow brown coats, colonies were only observed in a few far flung regions of their former range; the wallabies almost became extinct.  Although hunting has since been made illegal and few if any are actually shot by hunters today, the yellow foots are still in trouble.  Clearing practices and the introduction of feral goats have destroyed much of their former habitat.  Goats are particularly troublesome as they eat the vegetation favoured by the wallabies.  Additionally, the goat’s hard hoofs (no native Australian animals has hard hoofs) destroys the soil structure which increases the likelihood of erosion.  Australian authorities have instigated a campaign against the feral goats and regular aerial culling has reduced goat population numbers which has allowed the wallabies to expand their range to the point that the population is now slowly recovering.

The yellow foots live high on the scree slopes and sleep most of the day in rock overhangs and caves, only migrating to the lower slopes in the late afternoon to spend the evening foraging on vegetation.  In the morning they move upwards onto the scree slopes to avoid one of their natural predators, the Wedge-tailed Eagle.  

LEFT:  Yellow-footed Rock Wallabies enjoy sitting on rocks which is their favoured habitat.

It rarely rains in the arid region, however, when it does the arid region is transformed form a dry arid desert environment to a lush green tapestry of vegetation.  Rain had fell for almost a month before my visit and areas usually devoid of vegetation were carpeted in green.  This increase in available vegetation meant that the wallabies did not have to move to the lower slopes to feed.  Although the recent rain and increase in vegetation will no doubt allow the wallabies to breed thereby adding to the population, it did mean that photographic opportunities were somewhat less than optimal. 

CHALLENGING ENVIRONMENT

Photographing in the wallaby area is very challenging for several reasons.  Dust is a BIG issue and keeping sensors clean is almost impossible when changing lenses.  Another challenge is the actual time that you have available to actually take photographs of the yellow foots.  As mentioned, they live high on the scree slopes and venture down to lower elevation only in the late afternoon, leaving for the scree slopes in the early morning.  The topography of this area is such that the sun drops behind the scree slope in the late afternoon leaving roughly 30-45 minutes in which you can capture the wallabies on "film" before the sun and light is gone.  Likewise, in the morning you have about the same amount of time before the sunlight is too harsh (unless cloudy conditions prevail).

I was keen to shoot portraits, however, sneaking close enough to acquire a full frame portrait was next to impossible on this visit.  There was just too much vegetation around for the wallabies to feed on and as such many of the individuals didn't approach close enough to my hide in the rocks.  So rather than worry them by attemopting to get closer, I concentrated on aquiring several environmental shiots tht depeicted the animals (hopefully with tail) in its rocky environment.

No matter what the photographic result, it's always a pleasure to share some time with the yellow foots watching them as they bound along the rocks at almost supersonic speeds!  This animal receives 10/10 for agility,  flexibility and speed.

Search the archive for addtional Yellow-footed Rock Wallaby images & my blog post in 2009

Cape Du Couedic Lighthouse - Kangaroo Island

Kangaroo Island boasts several lighthouses which in between observing the animals are well worth a visit.  My favourite lighthouse was the lighthouse established on most southern shores of the island adjacent to a large New Zealand Fur Seal colony.  Although this lighthouse is not the oldest establishment – the Cape Borda and Cape Willoughby lighthouses were commissioned in 1858 and 1852, it certainly is the most picturesque. 

LEFT: The Cape du Couedic Lighthouse located along the southern coastline of Kangaroo Island.  Time were tough at the lighthouse in 1911 as indicated by the Log Book.

The Cape du Couedic Lighthouse, the fifteenth lighthouse to be commissioned in South Australia was constructed between 1906 and 1909 after three shipwrecks in the area claimed the lives of 76 souls.  The tower itself is comprised of 2000 large pieces of local stone.  Due to the lack of a road system, all construction supplies were brought in by boat to a cove 1 km away.  The cove offered some protection from the large southerly swell, however, surrounding the cove were steep cliffs.  A flying fox powered by a small petrol driven engine was used to ferry stores to the top of the cliff.  In addition to the tower and light, three four roomed stone cottages were built for the head lighthouse keeper and his two assistants.  The first light used at the lighthouse was manufactured in England by Chance Brothers and ran on kerosene fuel. Resupply was 4 times a year and mail was delivered fortnightly via horseback to the lighthouse staff.  The lighthouse sported modern rescue equipment which included rope ladders to scale the cliffs and rocket propelled lines. 

Times were harsh during these early times and it was not unknown for keepers to work exceptionally long hours for weeks at a time with little time off.  It was a regular and constant watch to protect passing ships from the treacherous coastline.  Three keepers operated the light station and maintained the light.  Every two hours the light mechanism had to be manually wound up.  The men worked in shifts and were rostered on every day of the week.  It's not surprising that from time to time they did not see eye to eye.

LEFT:  Cape Borda Lighthouse circa 1858.  A small canon was used to signal ships that danger was close by when low lying fog obscured the light.

An extract from the Log Book kept at the lighthouse reads:

"Wednesday 13th December 1911

Insubordination of the 2nd keeper

At 9 am 2nd keeper came to me and said, I want a day off.  I said it is not granted and I want to get on with the painting at the fox.  2nd keeper then said I am going to take a day off.  I then said as Head Keeper you are disobeying my orders.  He then said you are no body.  he then left the Station.  He rejected my advise and the left the station against my wishes, and was absent from the Station without leave for 12 hours - Head Keeper"

Time off and holiday leave is now an expected and precious part pf out lives.

At the lighthouse site is a period photograph of the keeper, his assistants and canine friends.  It’s possible to study the location of the people in the image, then position yourself to exactly the same location and stand exactly where they stood.  It’s impossible to imagine their thoughts at the time, but certainly they couldn’t not have imaged that I or anyone else would be standing here with a Canon 1D series camera around their neck and a Toyota Landcruiser parked along the way!

Final Preparation - 2 weeks with Australian Sea Lions & Yellow-footed Rock Wallabies

Preparing for a two week trip to Kangaroo Island, South Australia where I'm photographing the Australian Fur Seal (Arctocephalus pusillus), the World's fourth rarest seal species.  The Australian Fur Seal inhabits a small area of Western Australia and can be observed in a few localities on and around Kangaroo Island  in South Australia. The seal grows to a length of approximately 2.3 meters and weighs in at roughly 230 kilograms.

After a week or so on Kangaroo island, I'll head north spending a day or so at a favourite location near Port Augusta to photograph honey eaters and small birds.  I call this "birds on sticks" as many of the birds perch on branches above permanent water holes.

From here, I will be heading into the northern Flinders Ranges to locate (already know where they are) and photograph the beautifully coloured and marked Yellow-footed Rock Wallaby (Petrogale xanthopus), a species listed as vulnerable under the ICUN Red List classification.

During this time I will be camping from my four wheel drive vehicle.

Although only a relatively short trip (~14 days), I believe it should be enough time to capture some behavioral images of the seals and wallabies.  Hopefully, if the night skies are clear I'll also be able to photograph southern sky star trails.  Two positives photographing star trails in central Australia is the lack of light pollution; the nights are dark as coal when the moon is not present, and the lack of aircraft flying into your frame.  I found when photographing star trails in the US, the ever present aircraft flying overhead  a little annoying.