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.

Hammerhead Sharks, Indonesia

I had be told that this area was prone at certain times of the year to schools of hammerhead sharks, however, didn’t expect to see them.  I’ve dived with lone hammerheads on several occasions, but I have never encountered a large school.  Sharks aren’t common to see, and when you do see them often they are fleeting glimpses that last less than a few seconds.

LEFT:  A Scalloped Hammerhead Shark surrounded by Banner Fish cruises past.

The water I was diving was along the edge of a tectonic plate and as such was very deep; a coral encrusted shelf sloped away into the abyss and the sea bottom was over a kilometre below.  Unfortunately, on this day the weather was overcast and the water was not as clear as I would have liked.  The current has picked up along the reef edge and entrained quite a bit of silt and sand in the water column.  Levelling out at a tad over 30 meters (100 feet) I hovered above a sandy plateau that extended a short distance before dropping off to unimaginable depth.

The Edge of the School

I then saw my first hammerhead in the distance.  It was a large individual reaching roughly 4 meters (15 feet) in length.  It kept its distance and disappeared as quickly as it had appeared. Making my way over the sandy plateau I began to descend further until reaching 47 meters (150 feet) in depth.

LEFT:   Swimming into the school, several Scalloped hammerhead sharks patrol beside me.

It was then that I saw a mass of movement directly in front of me; I had reached the edge of a school of Scalloped Hammerhead sharks.  Quickly counting, I calculated that 9 sharks were immediately within my vision, these sharks swam past me to be replaced by more sharks following.  I swam into the school and all I could see was shark!  Every few meters there was a shark, followed by another which was beside another – there were sharks everywhere – WOW.  I noted that all the individuals were females and I wondered where the males were!

I knew I had to photograph quickly as the time allowed at 47 meters is minimal and I was already at the verge of entering decompression.  Moving my strobes out from the housing, I attempted to position them in such as way as to minimise the back scatter, that I knew would occur from the suspending silt and sand.  I fired a few frames and as the duel strobes (flashes) whined to recharge, I observed that the sharks became a little agitated; one individual dropped its pectoral fins and arched toward me like a fighter plane peeling away from the squadron.  The shark came within arm’s reach before veering off to join its brethren.   The reason for the behaviour is quite simple, and occurs with most active sharks when divers use electronic strobes.  The recycling from the battery pack to the flash cell causes a high frequency whine which is picked up by the Ampullae of Lorenzini, the name for a shark’s super-sensory electrical device; this momentarily excites the shark.

Fearful

I wasn’t prepared for the fast approach and immediately felt apprehensive; suffering the effect of slight narcosis did not add to the situation.  As my heart rate increased due to my sudden apprehension, two hammerheads swam in my direction to investigate; sharks are similar to dogs in that they can smell fear!  In situations like this fear can feed on fear itself and spiral until one looses control of the situation. 

Realizing this, I regained my composure, aimed and fired off another frame followed by another.  I swam towards the school again and was annoyed that there was so much sediment in the water; I hoped the light from the flashes was not reflecting on the sediment, but there was little time to look at the camera LCD screen to check – things were happening very fast as hammerheads glided in from the main school to investigate me and my whining strobes!

I was over 45 meters in depth and well into a 15 minutes decompression obligation (the time I would have to spend at a shallower depth to allow nitrogen off gassing; failure to complete this time may lead to decompression sickness).  I was trying to swim somewhat beneath the sharks so I could shoot with a slight upwards angle; a photographic composition like this would show the power, size and presence that such an animal deserved. 

I Wanted the Perfect Shot

I wanted to get the perfect shot.  I wanted the right composition and exposure.  I wanted three sharks in the correct position.  But, there wasn’t the time.  To continue would be foolhardy.  I then realized that my time was up.  I had to depart immediately for a shallower depth or suffer the consequences of either low air or too greater decompression obligation.  It’s at times like this that you must understand that the photograph is second to your own safety. 

I had reached the threshold and I was pleased that I had listened to reason and not continued.  With slight regret at not been able to take the perfect photograph, I slowly ascended to my decompression depth.  However, I was elated at being able to swim with of a school of hammerheads at close quarters; the experience transcends the photographs! 

BELOW:  A Scalloped Hammerhead shark swims above me before changing direction abruptly to make another pass. Encounters with large predatory animals are uncommon and this experience will remain with me for sometime.  Most of the images on this dive were shot at 35mm at ISO400, 1/125th @f8.

Natural History

Scalloped Hammerhead Sharks (Sphyrna lewini) are probably the most commonly found species of hammerheads located in coastal regions, appearing in very shallow waters such as estuaries and inlets. Their distribution in the water reaches from the surface down to a depth of approx. 275 m. The young, however, remain mostly in shallow waters along the shore to avoid the danger of falling into the mouths of predators. At certain times of the year and places, and during certain phases of their lives, scalloped hammerheads form very large schools, sometimes counting hundreds of individuals, but they also swim the oceans alone. Some populations remain stationary, others clearly wander, migrating in the direction of the poles in summer. Some sexually-related migrations have also been observed, e.g. females who undertake migrations during particular periods of their sexual development. 

As already mentioned, this shark species tends to form huge schools whose function is presumed to be manifold and may, among other things, concern feeding habits and reproduction. Although many studies also consider this behaviour to be a group protective function, this is somewhat questionable since the animals have practically no natural enemies after reaching full maturity. Groups of scalloped hammerheads prefer staying in regions which have pinnacles or sea mounts which reach from great depths practically to the water's surface. Latest research also shows that these sharks can make use of the earth's magnetic field during their migrations.

Why No Location Mentioned

You may wonder why I have not mentioned the location.  The reason is that all sharks are in danger from being over harvested by fisherman.  Schools of sharks such as the school I had encountered are in demand by the fishing fleet, not for meat, but for their fins.  The sharks are caught on long lines and pulled to the side of the boat, and a very sharp knife used to slice off their fins.  The doomed creature is then pushed away from the boat and left to die an agonising death.  The fins are used in shark fin soup which is a Chinese delicacy.

Albino Shy Albatross Chick (Thalassarche cauta)

On a recent field trip to islands off the coast of Tasmania, I observed a pair of non-albino Shy Albatross (Thalassarche cauta) tending an albino chick.  This chick, which was very healthy in appearance. was the only youngster iin the 2 breeding colonies that showed albinism. 

LEFT: Albino Shy Albatross Chick (Thalassarche cauta) is feed a diet of squid.

Congenital hypopigmentary disorders, known as albinism, result from a defect in the production of pigment (melanin) in the skin, eyes, and hair.  The condition is due to the dysfunction of the melanin producing cells.  The condition can occur when offspring inherit a recessive gene. from either parent.  The number of defective genes inherited determines the type of albinism.

Albinism affects both males and females, and is apparent from birth.  From my reading on the subject there are three types of albinism: OCA type 1, OCA type 2 and OCA type 3; each presenting with slightly different symptoms.

Whilst albinism is not an uncommon occurrence in animal populations, it is an uncommon occurrence in groups of species that have relatively low population numbers, such as Shy Albatross.  Boisey, R.E. (2003) states that OCA type 1 albinism occurs in 1 individual per 40,000 and OCA type 2 occurs in 1 individual per 15,000.  There is little research to reflect the occurrence of OCA type 3.

In general, species that present with albinism are predated upon and selected out of the population.  For example, an insect that is usually coloured white to blend in with its snow surroundings, but is black, will be predated upon and killed, removing it from the population.  Usually a recessive gene (trait) has a negative impact on an individual, however, if the inherited trait provides an environmental benefit or sexual advantage, it maybe carried forward into future populations (natural & environmental selection).

How albinism affects a bird such as the albatross is unknown, as generally these birds don't require effective camouflage to survive.  However, albatross do require excellent eyesight in which to spot prey beneath the surface of the ocean.  OCA type 1 and type 2 albinism causes sensitivity to light (photophobia), reduced visual acuity and involuntary eye twitching.  OCA type 3 also has reduced visual ability but not to the same extent as type 1 and type 2.  A lack of visual acuity would have an affect on an albatross once fully fledged. 

An albino albatross may survive if the population of prey is great and easily found.  However, if prey is difficult to find then I would suggest that an albino albatross may have difficulty feeding in the wild.

LEFT: Albino Shy Albatross Chick (Thalassarche cauta) and parent.  The pink face is a very obvious characteristic if albinism.

Please note that I am not a geneticist by training and information for this post has been obtained from several sources.

I wish this little fellow the best of luck in the future as he/she transit the world’s oceans.

Dancing with Hookers in New Zealand

Although I’d been told roughly where the Hooker Sea Lion's haul out, I was doubtful I’d see one; they are quite uncommon.  The beach I’d been directed to was long, isolated and ran parallel to a sand dune complex.  At the headland I’d already photographed a few New Zealand fur seals and a couple of sooty oystercatchers; which were doing their utmost to hunker down within the loose sand to minimise the effects of a strong sea breeze that had been blowing for most of the afternoon. 

LEFT: A male Hooker Sea Lion.  The head of a hooker looks completely different to others sea lions.

Looking farther along the beach from the headland I could see something that looked quite large and dark.  Initially I thought it was a New Zealand fur seal, but this seal seemed too large for a fur seal.  Hiking along the low tide mark, I was amazed to come across a massive animal in half moult with a face that looked less like a seal but more like something else – but what!    I knew hookers can be quite large, especially the males, but this animal must have weighed in at close to 150 kilograms (around 300 pound).  This did not in anyway look like the benign fur seals and California sea lions I was used to viewing.

LEFT:  Sleeping male Hooker Sea Lion  on an isolated in New Zealand.

At first I was wary of aapproaching close to this behemoth as I knew looks can be deceiving; my past experience with seals had taught me that although they looked cumbersome, seals and sea lions are capable of very fast, yet short-lived turns of speed.  But this old fellow seemed content to just lie on the beach in what appeared to a deep sleep – although I knew he wasn’t sleeping, as every now and again he would yawn, or open an eye to dutifully watch that I maintained a reasonable distance. 

The jaws of the hooker looked formidable; large sharp teeth protruded from an exceptionally cavernous mouth.  A small armada of flies swarmed around his jaws as he opened and closed them; I wasn’t close enough to smell his breath, but I can only imagine. 

 LEFT:  A female Hooker Sea Lion walks to ward the male after exiting the ocean.  The differences between male and females is very distinctive.

Rebecca and I spent probably close to 45 minutes with the sea lion and were about to depart when we noticed another seal aapproaching from further down the beach.  It soon was apparent that this was a female, and like all males his half sleep instantly evaporated as he sprang to life making himself look tall as he watched the female exit the surf and make her way towards him.   After what appeared to be some affectionate nose touching and snorting, the two then about faced and marched off toward the surf to take to the sea.

LEFT:  A male Hooker Sea Lion sleeps in the sand dunes.  Hokers cover themselves in sand to regulate ambient temperatures; the sand stops them getting sunburnt too!

HOOKER SEA LION FACTS

• SIZE: Male length 2 - 2.35 meters (6.5 - 7.7 feet)
• SIZE: Female length 1.6 - 2 meters (5.2 - 6.5 feet)
• WEIGHT: Male 300 - 450 kilograms (660 - 990 pound)
• WEIGHT: Female up to 160 kilograms (352 pounds)
• SEXUAL MATURITY: 3 -4 years with males breeding after 8 years
• LIFE EXPECTANCY: 18 - 23 years (females/males)
• CONSERVATION STATUS: Threatened (New Zealand marine Mammal Protection Act.  Classified as vulnerable by IUCN Red List 2007

The Hooker's sea lion (Phocarctos hookeri) also known as the New Zealand Sea Lion, is one of the World's rarest and most endangered sea lions.  They were extensively hunted for their hide and oil until hunting was banned in New Zealand in 1893.  Today, the sea lion has been designated as a Threatened Species under New Zealand's Marine Mammals Protection Act and is listed as Vulnerable on the IUCN Red List. 

BREEDING & FEEDING

Hooker Sea Lions breed almost exclusively on New Zealand's sub antarctic islands and haul out at a number of locations between Macquarie Island and the South Island of New Zealand.  Their favoured haul out areas are sandy beaches, and often individuals can be found resting in depressions within sand dune complexes up to 2 kilometres inland.

Hooker Sea Lions are opportunistic feeders with a main diet of cephalopods, crabs, crayfish, and fish, however, fur seals and penguins have  also been documented as prey.  Similar to elephant seals they are excellent divers and sea lions often reach depths between 300 and 600 meters. 

THREATS & CONSERVATION

The total world population of hookers was estimated to be between 12000 and 14000 individuals; however, in 1998 a mass mortality event occurred which drastically reduced their numbers.  The reason for the mortality event is unknown, but it highlights the risk faced by a species that only breed at a few site worldwide.

If a problem were to occur at any particular site, such as introduction of a disease or another mass mortality event, then the loss of one breeding site would be cataclysmic with regard to species recruitment.

A more insidious threat to the sea lion is the fishing industries use of trawl nets to catch squid .  Often Hooker Sea Lions will become entangled in the nets and drown as both the fishing fleet and the sea lions are targeting the same prey – squid. This said, the fishing industry is cognisant of the bi-catch problem and has introduced capture-release devices to many of their nets resulting in less sea lion deaths.

Yellow-eyed Penguins - New Zealand

The Yellow-eyed Penguin (Megadyptes antipodes), named the “Hoihi” by the indigenous Maoris, only lives in New Zealand and is one of the rarest penguins in the world with a total population of about 4000-5000 individuals of which 1200 to 1600 are breeding. About one-quarter of these live on the east coast of the South Island of New Zealand and Stewart Island. Most of them live on Campbell and Auckland Islands, about 600 km to the south in the sub-Antarctica.

NATURAL HISTORY

The Yellow-eyed Penguin is the largest penguin found in the temperate zone and is roughly 70 centimetres in height and weighs around 5 kilograms.  The penguins gain their name from the distinctive golden feathers which form a crown along their head and a bright yellow stripe that runs to the eye and around the back of the head.  Non breeding individuals lack this ornamentation.

Yellow-eyed penguins spend most of the daylight hours up to 20 miles from shore feeding on opal fish, silverside, sprat, red cod, and arrow squid at depths to 400 feet.  As such, they are excellent underwater swimmers and are adapted to holding their breath for up to four minutes.

LEFT: Classic image of a Yellow-eyes Penguin standing above thre dune foreshore scouting quickly for predators before turning and making its way to its nest and chick.

Their usual habitat is dense, cool coastal forests which afford the penguin shade during the day, shelter from the elements and protection from aerial predators.  Where forest is not available (due to farming practices and land clearing in New Zealand) flax and tufted grass areas are chosen amongst sand dunes.  Colonies and individual nets are scattered affairs and it’s not unknown for yellow eyes to trek up to a mile inland to their nesting site.  Unlike other penguins, who in the breeding season may stay on land during the day, yellow-eyed penguins spend the day at sea feeding before coming ashore at early evening to walk to their nesting site (except in the pre egg and moulting time).

LEFT: Yellow-eyed Penguin enters foreshore vegetation on the way to its nesting site.

YELLOW-EYED PENGUIN CONSERVATION

Because of its threatened species status, the Yellow-eyed Penguin Trust was established in 1987 to help conserve the penguin by protecting vital penguin habitat.  As part of the trust’s activities, farming areas were set aside and artificial nesting containers created in the hope of increasing the numbers of penguins.  Visitors to New Zealand are encouraged to visit areas that have breeding boxes established to observe and learn about the penguin.  Seeing a yellow-eyed penguin in semi-controlled environment is relatively easy and areas set aside like this provide an ideal platform to educate the public in penguin conservation.  However, my goal was to photograph the penguin in the wild; I particularly wanted photographs of the penguin coming ashore.

ABOVE:  Yellow-eyed Penguin storms the beach after a day feeding at sea.

To assist in locating and photographing the penguins I engaged the services of a local penguin guide from Back 2 Nature Tours.  Chris, the owner was a very knowledgeable and enthusiastic guide who was more than willing to try and help us photograph the penguins without disturbing them.

PHOTOGRAPHING THE PENGUINS & PENGUIN ETIQUETTE

Whenever I photograph wildlife, it’s important to understand the habits of your target animal so as to avoid causing undue stress on the animal.  This is particularly important with regard to the yellow-eyed penguin as disturbance is one of the major concerns with regard to the conservation of this species. 

Unlike other penguin species, the yellow eye is very highly strung and will easily jump at its own shadow!  It isn’t a sociable animal and they shy well away from humans, and even prefer to nest out of sight of their own kind.  This is a prime concern when photographing these penguins in the wild, for if the penguin sees you, often they will abort their shore landing.

As you can imagine, photographing this penguin species is not an easy task!  I soon learnt that it’s very difficult not to be seen by this penguin; their eyesight is phenomenal – getting close enough to obtain a decent photograph is tantalizingly difficult.  You will need a good telephoto lens and some type of camouflage to break up your body silhouette.  I spent about an hour lying in the sand waiting for the penguins to make their appearance.  I’m quite sure that to a passer by I may have looked like a military sniper a target rifle!

LEFT:  Part way up the beach, a Yellow-eyed Penguin pauses to llook for potential predators.

If you don’t have a hide established, or if your walking along the beach and observe the penguins coming ashore, it’s very important that you DO NOT stand up, but lower your body as close to the ground as possible to reduce your footprint.  Remember that these birds are very shy and easily scared – if you scare them and they decide not to land, then the chick will go hungry that evening.  Always give the penguin right of way!  If you see a penguin landing, stop, lower yourself to the ground, and wait for it to make its way to the dunes before resuming your activity.

As dusk approaches, the penguins begin to come ashore.  Unlike Blue Penguins that often come ashore in rafts of 10 to 20, the yellow eye storms the beaches either signally or in pairs.  Initially you will see them swimming about just past the breakers, as they scrutinise the shore searching for possible predators.  If they see you, they will not land!  Once they believe it’s safe, they will slowly make their way through the breakers to the beach.  Once they have reached the beach, they are still very mindful of anything in their vicinity, so it’s paramount that you keep hidden and do not move about unnecessarily.  Once the penguins have determined that the area is safe, they will slowly walk up the beach, into the dunes and eventually to their nests.  It’s very important that you do not follow them to their nest sites as this will stress the penguin and the chick (s).  Be content with watching the landing and observing the penguins as they make their way across the beach to the foreshore and dunes.

ALWAYS REMEMBER YOUR CAMERA

An odd title I know as you would think a photographer would err always have his camera with him - well not so!  I was with Chris from Back to Nature Tours doing a recognisance of the area Rebecca and I were going to shot the following morning.  Rebecca and I had already scaled a rather steep dune to the beach twice that day, so Rebecca opted to spend her time around the upper sections of the cliff looking about while Chris and I ran down to the beach for him to point out respective penguin access trails to me.  I left my camera in the car to save the weight - BAD MOVE.  As Chris and I rounded a corner on the dune, there was a yellow-eyed penguin half way up the dune.  The wind was blowing and the sand was being blown about the penguin's feet.  As Chris and I sat down, I wasn't that "pissed off" about not having my camera as the light was rather dull, although the penguin was close enough to get a full frame shot with a Canon 1 D MK3-S with a 70-200 lens.  What did really BUG ME major time was when the clouds parted and ray of golden light struck the penguin!!   I kid you not - this was the shot and where was my camera - IN THE CAR!   Was I annoyed - YES.  Am I still annoyed - YES.  Will I do this again - NO.   Message to be learnt, always carry your gear even on a recognisance outing and NEVER leave it in the car.

It was unfortunate that I only had a few days to search for the penguins.  I think with a longer time period far superior images can be aquired with patience, skill, and luck!

If your interested in yellow-eyed penguins, navigate to these links for further information.

• Yellow-eyed Penguin Trust New Zealand
• Back to Nature Wildlife Tours (guiding & advice)