The Sex Life of the Komodo Dragon

The most exciting interview I recorded last year was in the komodo dragon enclosure at London Zoo.  Part of the interview features in the latest part of the series Sexual Nature on the BBC World Service's science slot, Discovery, and first broadcast on BBC Radio 4 in January.  

The Komodo dragon is the world's largest lizard - the biggest recorded was a male 3.13 metres long (more than 10 feet long) and weighed 166 kilos.  Presenter Adam Rutherford and I met London Zoo's male dragon, Raja - a mere 7 feet long.  Senior reptile curator Ian Stephen introduced us and - as you can hear - answered every question that Adam could throw at him on dragon husbandry, virgin birth or parthenogenesis in these giant lizards, and courtship and sex in komodos.  Many of the gory details didn't make it into the broadcast programmes so on this page I've posted more of the audio we recorded.

A Tale of Two Penises

If you want to hear what happens when male and female dragons mate, this interview segment is for you.   Courtship involves several days of 'bipedal wrestling' and culminates with the likes of Raja revealing his hemipene (a sort of double-ended penis).  The image below shows those of another species of monitor lizard - just in case you are finding hard to picture...

Poor old Raja has yet to perfect his lurve technique so Ian and fellowkeepers have had to give him a helping hand.  All is revealed here.




Komodo Virgin Births

Under some circumstances, female komodo dragons can produce offspring without the wrestling, injuries and hemipenes.  Several zoos in the past ten years have documented instances of 'virgin births' or parthenogenic reproduction in komodos.  These were individuals who had not mated.  At London Zoo, they had a clutch of asexual eggs laid by a female called Sungai, most of which hatched.  All dragons produced this way are male.

Herpetologists speculate that a female dragon might use this male-making trick if the lizard comes ashore alone on a hitherto komodo-free island.  She produces some sons with whom she can then found a new breeding population.  Ian Stephen and Prof Jennifer Graves of La Trobe University in Australia explain in this slightly longer audio segment from the BBC programme.




Filming, Feeding and Fondling the Dragon

London Zoo's Raja is, in fact, a Bond dragon.  He was filmed for a CGI sequence in 'Skyfall' - the scene where 007 has a fight in a pit of komodo dragons in a casino in Macau.

Curator Ian told us that the celebrity reptile was not at his liveliest the morning in December we visited.  Raja had just downed 15 kilogrammes of horse carcass.

Raja was docile enough for us to creep right up to him and for Adam and Stephen to give him a stroke.

Close up, under the dried blood and dust, komodo dragons are colourful.

There is more on feeding komodos (including advice on avoiding a fat dragon) and the experience of being inches away from one of these magnificent reptiles in this segment of audio.

The Ants with Three Sexes

While making the recent BBC Radio 4 series, Sexual Nature: A Brief Natural History of Sex, I came across some research on North American ants with an extremely weird mating system.    They have three sexes  - sort of.

The strange sexual antics are going in at least two populations of seed harvester ant, Pogonomyrmex, which live in southwestern United States and northern Mexico.   'Sexual Nature' presenter Adam Rutherford interviewed Joel Parker who’d done some work on them a few years ago. 

Unfortunately the interview we recorded with Joel, at Plattsburgh University in remote New York State, didn’t make it into the final cut of the series.  But it is one of those Aren't-Ants-Amazing stories, deserving of more time than we had in the 'Sexual Nature' slot.   So I've posted a link to the audio of Joel's interview below. 

Before getting stuck in, it helps to be armed with the basics of who's who in a regular ant colony, and vanilla reproduction and parentage in ants. 

There is the queen ant of the colony who is the one reproductive female in the family.  She is the result of a mating between a male and female.

Pogonomyrmex queen

There are the workers who are also female but they are sterile.   They don't reproduce.  They  gather food for the colony, defend the nest, do nursery duties etc.  They are queen's daughters - the results of mating between female and male parents.

Pogonomyrmex workers

Third, there are males.  They have just one parent - a queen.  They hatch from her unfertilised eggs.  No fatherly input.  Males are made merely for their sperm and are only produced at mating time.  They don't live very long.

Male Pogonomyrmex being killed by a spider

To recap, in a regular colony, queens and workers are the result of matings between a female ant and a male ant.

But in these two strange Pogonomyrmex populations - one is red, the other is black -  Joel et al discovered that the queens need to mate with one kind of male to produce future queens and another kind of male to produce the workers.  The survival and future of an ant colony needs both queens and the worker caste so you can argue that the two types of males amount to two sexes.

What makes this situation even more intriguing is the two populations are dependent on each other.    Red queens mate with black males to make workers, and black queens need red males to make black workers.  New queens are made through red-on-red and black-on-black sex.  So the whole system actually needs four sexes. 

Here's Joel Parker talking about all this and how it might have come about.

Also, read more in this article by Joel Parker, published in 2004 in 'Trends in Ecology and Evolution'.  This piece from the Public Library of Science (Biology) is also good on the number of sexes in nature.

Ocean Acidification, Corals and Ken Caldeira

Image credit: The International Geosphere-Biosphere Programme and Globaia

This is a spin-off post from the radio series for the BBC World Service I am currently producing, Discovery: The Age We Made.  Presented by science writer Gaia Vince, it consists four programmes looking at the notion that humans have launched a new geological time period on the planet, the Anthropocene.  

Further down,  I have posted the audio of a great interview we did with leading climatologist Ken Caldeira on the seemingly likely fate of the world's coral reefs, because of the geologically extraordinary alterations we are making to the Earth's atmosphere.

We talk to leading earth and environmental scientists about the changes to the global environment our species is making which are so profound that they will leave physical, chemical and fossil marks in the rock strata forming today.  Homo sapiends is creating an assemblage of geological evidence that would tell any geologist in the far flung future (millions of years from now) that something forced the Earth into a new state - or down "a different trouser leg of geological time," as one of our interviewees put it.

The second part of The Age We Made focusses on climate change and the other consequences of our fossil fuel emissions, notably ocean acidification and its likely impact on the world's reef building corals.

About one third of the 10,000,000,000 tonnes of carbon we now put annually into the atmosphere as carbon dioxide dissolves into ocean waters.  Simply put, it forms a weak acid, carbonic acid.  Humans have been building up to this 10 billion tonnes per year emission output since the Industrial Revolution.   The acidity of shallow seawater has been creeping up, in step.  The latest measurements show that ocean acidity in the top levels has increased by about 30% on the last one hundred years - apparently, the most rapid rise measurable in Earth history.

This is a grim development for corals, and the millions of fish and other marine species that live in the reef ecosystems which the colourful, mineralising ones build.  Coral organisms make their skeletons from minerals, also dissolved in seawater.  The more acidic the waters, the harder it is for them to do this.   Some reefs in the Great Barrier recently measured are actually dissolving, such is the pH of the water now.

The finding about the dissolving corals of Australia's Great Barrier Reef came up in one of the interviews we did with Prof Ken Caldeira of the Department of Global Ecology at the Carnegie Institute for Science at Stanford.  So too did the suggestion that coral reefs would not be sustainable anywhere in the global ocean by 2050.  Cramming everything we wanted to put in the broadcast radio programme was impossible, so here you can listen to part of Ken's conversation with Gaia at greater and compelling length.   Prof Caldeira puts our CO2 emissions (particularly the rate of them) and their effects on the oceans into a stark geological time perspective.



There's a couple of minutes towards the beginning in which Ken talks about the processes in the normal long course of geological time which have kept ocean pH levels relatively stable.  Stick with it!  Because it helps to explain why what's happening today is so "extreme" to quote Prof Caldeira.

The last time anything comparable happened to the planet's oceans was about 60 million years ago, during the Paleocene-Eocene thermal maximum.  It was such a long time ago, that back then, horses were like the little one on the right.

This Google Earth video tour of ocean acidification is also excellent, in part because it shows graphically how acidification has increased and is projected to rise over the next few centuries.   It also nicely explains some of the basic science neglected by me here.

Turkey - Moyy Hotel, Camlihemsin

An perfect 5 out of 5 hotel recommendation for Camlihemsin, gateway village to the Kackar Mountains.  This is Moyy Hotel.

The hotel is the last remaining old building in the main street of the village.  It was rescued from demolition a few years ago by the hotel owner Ozlem Erol.  She has done an amazing job in restoring the interiors and exterior of the 80 year old house.  It had been disused and was in rack and ruin for three decades.

Rooms come with two beds, or a double.

This double looks out on the Firtina River and mountains through which the river rushes.

Our two bed room cost about £60 per night, a price which included delicious breakfast on the balcony (also overlooking the river).

....including excellent local cheeses,

And these cakes and pastries. 

The dinners here were also superb and good value at about 30 Turkish lira, about £12.  If you ever come to this area, stay in this hotel for at least some of the visit - Moyy Miniotel.

The road north of Camlihemsin is overlooked from on high by other interesting old buildings.  18th century mansions - many derelict or decaying - which were built by locals who made stacks of money elsewhere.

Turkey - Kackar Mountains 2

The starting point for a beautiful but frustratingly short walk we did towards the central massif of the Kackars from a village called (Upper) Kavrun.  This was after we'd finished our four days trekking with guide Mehmet Demirci. 

At this point our base was the village of Camlihemsin, way down towards sea level.  To get to Kavrun, we took a minibus which took 1 hour and 15 minutes.  First 20 minutes to main tourist village of Ayder on a good tarmac road and the final 55 mins on steep switch-backing unmade track.  Bumpy but beautiful.

There were a handful of other tourists (Turkish) in the bus but they didn't strike out towards the mountains.  We didn't encounter any other walkers during the 3 hours we had to get as far as we could and back before the minibus headed back to Camlihemsin.

This was our turn-around point.  Actually we did see one other tourist.  A fat middle aged bloke in shorts with a fishing rod and in breach of the Kackar National Park rules.  A bit more enforcement of these rules wouldn't go amiss I reckon.  During the preceeding days I lost count of the number of spent hotgun cartridges I saw.

I think the run of weather we had on this day and the preceeding five was unusual for September in these parts.  Apparently September is the second wettest month usually in this part of Turkey and the northern side of the Kackars is notoriously cloudy and wet.  Mehmet did say they had an abnormally dry summer in 2012 so perhaps this was just an extension.
 

I would love to trek in this region again and this time focus on this central massif region, crossing from the north side to the south, and back again.  We missed out on the truly spectacular trails I now realise. 

Anyway we had to be back at the village within 3 hours although we had to wait an extra 1 hour while the dolmus driver faffed about with other errands in Kavrun.  While we waited, youths set off fireworks and a simple-looking man in a multi-coloured Biggins-Doing-Jackanory jumper repeatedly fired a pistol into the air next to the minibus. 

We returned to Camlihemsin with just locals, including this elegant woman who had a big white sack of something to take down the mountain.

Some of the Hemsin women look amazing with their trinket-adorned, coloured turbans.  The woman with the sack was particularly classy with this crimson and black number, plus 2 tone mauve paisley top.

Turkey - Kaçkar Mountains 1

A view to the greatest summits of the Kaşkar mountains where we've been for the past week.  Almost 4,000 metres above sea level, they are the highest peaks of the Pontic Alps which run from northeastern Turkey, parallel to the Black Sea, into Armenia.

MJC pauses to pose on our fırst walk on the Kotençur plateau where we were based for three days.  This is above a valley just to the west of the central Kaşkar granite massif.  Just to the right of his right shoulder is the tin shack that was our base camp.  Further to the right ın the distance is the derelict vıllage of our guide's great grandfather.

Here is our guide Mehmet - a native Hemşin, very interesting on local mountain culture and excellent on the plants, not so expert on the birds and a helluva fast walker.

The plateau pastures are strewn with these white crocuses.  They flower late summer and early autumn and signal to the mountaın folk that it's time to get ready to leave the highland villages or yaylas for their lower lying homes.

Here is our boutique mountain hut - interior shot to follow.

You can't move for gentians up here.  At least three species in this area.

MJC sups at the spring of the deserted Upper Amlakıt village.  The last inhabitant died ten years ago.  Photo taken just minutes before day 2 trek's most dramatic moment.

My skew-whiff cap may well be the result of my brush with mortality, climbing through the ruins of the village.  I lost my footing and fell backwards about two metres, landing in a bed of stingıng nettles and firmly wedged between two granite boulders.  Mehmet had to haul me out.

Even in mid September, the abundance and diversity of plants in flower was incredible.

These saffron crocuses were all over the place above about 2500 metres.  According to Mehmet, ın the wınter the bulbs are used to make a hot sweet drink called Sahlep, wıth boilıng water and some milk.

MJC is lurking to the left, attempting to blend in with the granite and lichen.

Ice 'lake' at 2700 metres.  I got knee deep but it was way too cold for full immersion.

One of the joys of walking here was pickıng and scoffing the wild raspberries.  Really sweet and not at all furry.  So much nicer than the ones ın Waitrose.

Some of Mehmet's lovely extended family who came up from the village below to have a picnic, chaın-smoke and gather bucket-loads of wild raspberries, blueberries and myrtleberrıes whıle chaın-smoking.

Interior of mountain shack with me packing and panıckıng ın search of something I'm convinced I've lost but haven't.  We all slept ın sleepıng bags on that pink seat.

About 300 metres lower, we spent the next night in the lower Amlakıt village in that dark brown pension you can just see on the left side of the photo.  During mid-winter, these houses are under about 5 metres of snow.

MJC at the village cafe with the best turkish coffee we've had on the holiday so far.  

Typical of the views from a forest path which apparently was one of the routes of the Silk Road.  We crossed a stream with flecks of gold (the largest full-stop size), in ıts sandy bed. It was the real thing - I am an ex-geologist.

MJC marches ahead into the lichen-strewn spruce.

The village of Hazındak comes into view as we break through the tree line again.

MJC tries to bond with some of the Hazındak elders.

Much more interestıng were these lovely ladies with their fantastic turbans and knitting.

The village imam makes an appearance, heading in the direction of the village mosque.  In most of the yaylas, the mosques are anonymous-looking tin or wood huts wıthout minarets.