Inside Nature’s Giants

I’ve been watching a heap of dissection documentaries recently for free on YouTube via a user named EvolutionDocumentary. They’re from the series with Richard Dawkins named Inside Nature’s Giants. It’s a paid account so all the documentaries are full length (no irritating 10 minute splits) and they have no ads either. WIN!

It’s incredibly interesting stuff so I definitely recommend having a look, and to make things easier I’ll relink them all here in sequential order.

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Herp Files: Red-eyed Crocodile Skink

These guys are seriously unique in appearance… I’ve never seen anything like them! The Red-eyed Crocodile Skink, Tribolonotus gracilis, is from the forests of New Guinea and is one of the few known lizard species that vocalises when in distress.

Interestingly, females of the species only have a single working ovary (the right ovary), and can only lay a single egg at a time. They also apparently exhibit mother-child family group tendencies. They have some frickin’ awesome armour on their backs as well!

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Herp Files: Gekko Eye

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Nope, not an albino turtle

A leucistic green sea turtle (spotted on r/pics).

On first appearances I’m sure the majority of us would proclaim with interest and enthusiasm, “WOW! An albino green sea turtle.” However, that isn’t the case interestingly enough! It’s actually a turtle with what’s known as leucism. According to wikipedia:

Unlike albinism, it is caused by a reduction in all types of skin pigment, not just melanin.

From my understanding, the best way to tell the difference is by looking at other parts of the body like the eyes (leucism can also be patchy in appearance where only some parts of the animals skin is affected). Melanin is the only pigment that contributes to eye colour (in the iris specifically), and hence why it’s possible to detect the difference between these two genetic disorders. (However, this method isn’t necessarily fool proof as I’m sure pigmentation attributed to melanin may vary a great deal across many different species, so genetic tests would probably be the only thing that is truly fool proof when it comes down to it).

A leucistic pigeon (not the normal coloured eyes and legs, and patches of normally coloured feathers).

In the below example using the alligator, when the eyes appear as they normally do, with grey/blue pigmentation, the animal is most likely leucistic, and if it has pink eyes lacking melanin pigmentation then it’s an albino.

A leucistic alligator

An albino alligator

People may ask why traits like albinism or leucism still exist in the wild when surely it has little if any benefits for animals? Evolution via natural selection unfortunately finds it relatively impossible to weed out traits like albinism and leucism which are recessive. That is that they aren’t exhibited by the animal (in what’s called its phenotype) unless the animal has two copies of the recessive alleles (one from its mother and one from its father). If it only has one, it will exhibit the same phenotype (it will appear the same) as would an individual without any copy of that allele.

Because of this fact, individuals who carry two alleles and appear white are likely to have a lower fitness level than other normally appearing individuals, and is thus more likely to be killed/predated prior to passing on its genes. However, because individuals can carry a single recessive allele for albinism or leucism without any changes to its appearance, if it ever mates with another individual who is carrying a single (or two) recessive alleles then offspring may be produced carrying this phenotype. Similar to genetic disorders in humans such as cystic fibrosis or sickle-cell anemia.

On a side note, during my volunteer work in Queensland at Mon Repos with sea turtles, I would often find white hatchlings. Unfortunately, the majority of them normally didn’t make it out of their shells and died in the burrows as a result of other genetic defects they also carried (they often had contorted bodies, and one I found had no eyes at all). In once case I even found twin albinos sharing a single egg shell. Sometimes you’d find abnormally large eggs an these would have two yolks or embryos in them. It was rare enough that they would actually develop at all, let alone develop and both be albino or leucistic.

Looking back I wish I’d had a closer look and could’ve worked out whether they were carrying albinism or leucism! I might have to rummage through my turtle photos and see if I can find some images of them.

Green sea turtle hatchlings, clearly some can survive, but also note the distortion of the vertebral scales along the spine of the white hatchling (though this is often seen on average hatchlings too).

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Eulamprus skink tail x 2

This is the tail of a Eulamprus tympanum tympanum from an individual my friend caught during her MSc in East Gippsland. It was caught in a pitfall trap, and when she pulled it out to have a closer look she noticed something a little peculiar about its tail.

Skinks are a family of lizards, Scincidae, and are renowned for their ability to drop their tails when threatened or caught by predators in an attempt to distract them and escape. The tails once lost grow back much the same as the old tail but with the new vertebrae grown out of cartilage.

Anyway, as usual this individual grew back its tail after having dropped it for whatever reason, and through some physiological mistake it grew a second tail end out of one side of its main tail.

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Newly discovered sea snake species: Hydrophis donaldii

A new species of sea snake has been found in Queensland reports this article from Science News.

A paper, published yesterday in the journal Zootaxa, announces the discovery and notes that the new species called Hydrophis donaldii is unique in having raised scales.

“H. donaldii had evaded earlier discovery as it prefers estuarine habitats that are poorly surveyed and not targeted by commercial fisheries”, explained Dr. Bryan Fry, a co-author on the discovery paper and an Associate Professor at the University of Queensland’s School of Biological Sciences.

The scientists collected nine specimens of this ‘viviparous or true’ sea snake from the coastal estuarine habitats of Weipa on the Queensland coast of the Gulf of Carpentaria.

“Weipa really is one of the last sea snake ‘Serengetis’. We can see over 200 sea snakes in a single night’s hunting, whereas sea snake populations have really crashed elsewhere through over-fishing removing their prey and also the snakes drowning in trawling nets.”

“All venomous animals are bio-resources and have provided sources of many life-saving medications, such as treatments for high-blood pressure and diabetes. This reinforces why we need to conserve all of nature as the next billion dollar wonder-drug may come from as unlikely a source as sea snake venom.”

H. donaldii is named in honor of David Donald, Dr. Fry’s long-time boat captain.

“Quite simply we would not have found this snake without Dave’s unique knowledge of the area. I told him we wanted to survey as many distinct types of habitat as possible and he guided us to the perfect spots,” Dr. Fry said.

It is also given the common-name ‘rough-scaled sea snake’ to reflect the unique scalation.

“We don’t know why it has been evolutionarily selected to have such unique scalation, but we will next study its ecology to learn more about it,” the scientist concluded.

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Herp Files: Atheris hispida (Hairy Bush Viper)

This is a species of viper, a venomous snake, found in Central Africa. Scientific name is Atheris hispida, common names include rough-scaled bush viper, hairy bush viper or spiny bush viper (for obvious reasons). It has some impressive keeled scales that almost give it a bristly appearance. They probably help a great deal with camouflage in vegetation, by breaking up the outline of the animal as well as giving it a leafy appearance.

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Herp Files: World’s Tiniest Chameleon Discovered

This little guy, Brookesia micra, was recently discovered on an a Madagascan island, with adults of both sexes reaching a maximum length of a mere 30mm making them one of the world’s smallest vertebrates as well! They’re so small in fact, that they can easily perch themselves on the tip of a match stick…! Making it most likely the easiest lizard species to loose, or better yet inhale.

See the full article here for more info and pictures.

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My Masters of Science project in photos

I finished my Masters of Science (MSc) at the University of Melbourne at the end of last year, and thankfully scored first class as did many of my good masters maties! I was looking at the goanna species Varanus varius and more specifically at the species phylogeography (wide-scale, historic gene flow), and its population / landscape genetics (small-scale, contemporary gene flow).

Brief findings:

• Historic gene flow – mtDNA analysis of ND4 showed the presence of 3 clades within the species, separated by montane biogeographic barriers (Great Dividing Range (GDR) and Mcpherson Range), and possibly the Burdekin Gap in northern Qld (dry habitat barrier). Although I’m just finishing up some final lab work and analysis to reveal whether its the Burdekin Gap or a pattern of isolation by distance that has split the clades in this area.
• Contemporary gene flow – Microsatellite analysis indicated male sex-biased dispersal was present within the species (males move further than females), no significant genetic structure over the 600kms^2 that I sampled indicating the species is incredibly dispersive (can move large distances), and that there was a more recent area of contact between two clades at the Hunter Valley, NSW.
• Evidence from both these markers and their analyses also indicated that the species was more historically restricted to the north coast of Australia in QLD, and when the climate become more favourable (warmer/wetter) in the south they expanded southwards.
• I also found evidence that the species had used the Murray-Darling river system and its surrounding forest as dispersive corridors to spread west inland and south from QLD. (Amazingly, some individuals from the GDR in Qld were more closely related to individuals from near Adelaide and northern Victoria (2000kms west/southwest) than they were to individuals 50kms to their east in Qld. It’s thought that flooding events will have also facilitated the spread of individuals down these river systems.

Anyway, I thought I’d share some of the photos taken during my 2 year MSc project. So bring on the photos! I’ll chuck my 2 cents in on top of each photo. By the way sorry for the poor quality of the photos, a lot were taken on my iPhone.

So this is the beasty I was studying and chasing around in the field on several field trips throughout 2009, ’10 and ’11, Varanus varius aka Tree Goanna or Lace Monitor. They were often found running along the sides of roads as it is easy terrain for them to walk on, or running around camping and picnic grounds.

I went on 3 field trips out to East Gippsland and Wilson’s Promontory, Victoria, Australia, where my supervisor had already been trapping for 2 or 3 years and had other MSc students doing their research on other creatures. I also went on a 2 week long field trip starting in Brisbane, Qld and drove down the east coast of Australia through NSW and into Victoria to try and fill sample gaps where museums had not collected genetic samples previously. I did pretty well, but often saw many more than I caught each day… Damn goannas were incredibly fast and quick to run up tries and evade us weirdos running around with dog noose polls.

Here are a few photos of the places and habitat I was trapping/catching these guys in.

The first 3 photos are from Wilson’s Promontory

The rest of the photos are from various locations along the coast in NSW.

At the time of the field trip down the east coast many areas of Qld and NSW were suffering those severe floods. The below are photos taken at Nymboida Pub, NSW.

This was the scene behind the pub, usually a small creek.

These were the 2m long aluminium traps I used to capture the goannas. They were a simple trap that just had a trap door held up by a pin that was attached to a wire running to the other end of the trap and inside it was tied to some chicken. When the goanna pulled on it the door shut and it was trapped. I also hung future baits from a tree nearby to fester up and send the smell off into the surrounding bush to attract them. Unfortunately they’d also attract things like wasps, one time in Wilson’s Prom a bag had 100s of European wasps all over it and in it eating the chicken… bastards!

Sand pads were also left outside the traps to see if goannas had come to check the location out but hadn’t triggered the trap. I also set up camera traps outside the aluminium traps at Wilson’s Prom (left side of the below photo tied to the tree).

This was a boy I caught near Newcastle, NSW. Once caught I duct taped their mouths and legs together to prevent the goannas hurting us or themselves while I measured them, weighed them and took blood samples from them for the genetic work.

Another big boy being measured out in East Gippsland.

I’d also take measurements of the head size, this one below has just had its snout taped and is about to be measured.

I’d use a syringe to take a blood sample from each individuals caudal vein/artery in their tail situated just below their spine. It took a while to get used to it but eventually I could do it within a few seconds.

Lizards would also be weighed. Although they are a sexually dimorphic species you couldn’t tell the females from the males if they were below 4kgs. Males were the only sex that grew past 4kgs, sometimes reaching up to 12kgs if they lived near a tip or camp site where food was abundant. This one below is on the smaller side so could have been either a male or a female.

Occasionally they’d be kind enough to hock up their last meal in the aluminium traps. The photo below is from the individual caught at Newcastle (pictured above). That camping spot had literally millions of cicadas pretty much screaming their calls constantly, so it was no surprise when this guy’s stomach turned out to be full of them, and a bit of fur from a possum.

These two photos below are of an individual from East Gippsland that had somehow managed to eat a juvenile echidna, spikes and all, and then been able to vomit them up?! That cannot have been pleasant at all…

While in Newcastle on the field trip we also hooked up with some of my supervisors scientist friends who were working on the biomechanics of varanids’ skulls and their bite force. They’d set up about 5-6 digital cameras in a semicircle around the individual to get a 3D image of its head, and then test its bite force using a pressure sensor. However, the one below wasn’t too interested in biting down as I suspect it was tired and had had enough.

See those bloody claws?! They use them for climbing trees, and most probably to tear at and hold carcasses they find while pulling flesh off them with their jaws. Here’re some closeups of the claws… epic talons! I was scratched quite a few times.

I often had to go to some extreme lengths, or heights rather, to capture some of these sneakily evasive goannas. They’d often climb straight up the tree at the first sight of a human and into the very thin branches at the top of it.

You probably can’t see it but there were actually 2 big males in the tree in the below photo. My mate and field assistant, who also was a freak rock climber, would happily tear up their trees bare hand with the noose pole to get the samples and data I needed! To attract these guys below we had by chance come across a dead wallaby and pulled it away from the road and under this tree where we tied it so it couldn’t be moved. When we showed up though there were 3 of them, one bailed before we were out of the care and the other two went straight up the tree. We got them both though muahahaha!

When letting them go I’d place them on a nearby tree so their claws were otherwise occupied with a grip and wouldn’t scratch me once I cut the tape. Then while holding the body against the tree with its freed limbs grabbing the tree trunk I’d take the tape on their snouts off. Often they wouldn’t move an inch and would just sit there pretending to be dead while you walked off.

Here are some more photos of the goannas we saw, and sometimes caught, on the road trip down the coast.

My supervisor and his son with one of the largest goannas caught in East Gippsland.

Some other herps I got to see on my trips. Feel free to tell me what the species are if you know them as I haven’t bothered to look these guys up yet.

A friendly little venomous surprise was waiting for me under a leaf in a pit fall trap bucket one morning, wasn’t keen to get him out by hand…

However, this guy below I was brave enough to pick up and have a better look at.

And non-herps. These are what I’ve always known as ‘spit-fires’ because if you touch them they spray some nasty chemical on you that burns like hell. Happened to me once as a child in the playground at school, since then I’ve never been done!

Eastern Grey Kangaroos at Wilson’s Prom.

THE END!

If for some reason you’d be interested in reading my thesis I’m more than willing to email it out just send me your email

Pete

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Herp Files: Copperhead Snake

This rare photo was taken of two Copperhead Snakes, Austrelaps ramsayi (I believe), today when they were spotted on the side of the road, either a male and female mating or two males battling for a female nearby. Found via r/Australia on reddit.com.

Funny coincidence, I actually stumbled across a dead one of these today on the side of the road that looked a great deal similar to the brown and yellow snake below. Probably the first one of this species I’ve seen in 10 years. A lot of these poor snakes get hit by cars when they’re warming themselves up on the roads. Luckily these two pulled off for a shag or wrestle.

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