About Me

My Photo

I've been a Canberran since moving here from Adelaide on the first day of 1980. I now live in suburban Duffy with my partner Louise Maher, ABC 666 radio and on-line journalist. Among my early memories is following Sleepy Lizards (Shinglebacks) around the paddocks north of Adelaide, guarded by the faithful bull terrier. I have always been passionate about the natural world, trying to understand how it works, how the nature of Australia came to be, and sharing those understandings. My especial passions are birds, orchids and mammals. I am now a full-time naturalist, running bush tours, writing books etc, doing consultancies, presenting a regular radio slot on local ABC, chairing a government environment advisory committee and running adult education classes. I was awarded the Australian Plants Society Award in 2001 and the Australian Natural History Medallion in 2006, both for services to education and conservation. As part of my fascination with our Gondwanan origins I've been running tours to South America for the past few years.

Wednesday, 1 July 2015

Malaysian Borneo; first impressions

I have just come back from a couple of very interesting (and enjoyable) weeks in northern Borneo, in the Malaysian states of Sabah and Sarawak. It was an unexpected trip, in that I was asked to accompany a natural history tour for reasons that are of no great interest to anyone else in this context. My explorations beyond Australia (other than a time in Europe over 30 years ago) have hitherto been limited to South America and Africa, so this was a real opportunity for me to see a part of the world with a very different biological history. 

Doubtless I'll be returning to Borneo in future postings here, but I've been asked to offer something of an overview while it's all still fresh in my mind, and so here it is. Firstly, in case you're not very familiar with the mighty island, here is where it is and how it's divided up.
My trip was limited to the 25% of the island which comprises the two Malaysian states of
Sabah (in the north-east) and Sarawak (in the north-west). The boundary between them is just to
the east of the tiny Sultanate of Brunei, which appears above as a rough W on the north coast.
The southern 75% of the island comprises Indonesian Kalimantan.
Map courtesy of Wikipedia.
It is the third largest island in the world (other than continents, including Australia, only Greenland and New Guinea are larger). Crucially, in terms of understanding its biology, it lies immediately to the west of Wallace's Line, named for the great 19th century English biologist Alfred Russell Wallace who recognised the clear distinctions between the fauna of Asia and Australia-New Guinea. Put simply, to the west of the line we find primates and hornbills, which to the east are replaced by possums and cockatoos. The line corresponds to deep-water trenches which mean that the land masses on either side of them have never been connected during glacial periods of low sea level. Of course things are never that clear cut in the real world, and in Sulawesi immediately to the east (on the edge of the map above) there are elements of both faunas, but it's a very useful rule of thumb. 
Thomas Huxley - the zoologist contemporary of Wallace, who coined the term Wallace's Line in 1868 - had it
running west of the Philippines, but now we recognise Ernst Mayr's version, which excludes
the Philippines from Wallacea. Wallacea is a region of somewhat mixed faunas between the largely 'pure'
Asian region and Australia.
Map courtesy of Wikipedia.
And to a visitor from Australia the 'exotic' nature of the fauna is very evident. (Reiterating, this is just an overview and I'll be revisiting these wonderful organisms in future postings.)
Rhinoceros Hornbill Buceros rhinoceros, Sepilok, Sabah.
A truly thrilling sight for a new-comer; apart from being so 'different' to our eyes, it
is quite enormous - up to 1.25 metres long.
Proboscis Monkey Nasalis larvatus, Labuk Bay, Sabah.
Another very special moment - this is one of the many Bornean endemics.
There are several major habitat types, with their own distinctive species, but the majority of the island is - or was - dominated by rainforest. I have to insert the proviso into that sentence because according to one apparently knowledgeable local we spoke to, 55% of the rainforest has disappeared in just the last 20 years, and most of the blame must be allocated to the pernicious palm oil industry. Any drive in Borneo will expose you to seemingly endless kilometres of the monoculture. It is not the only reason that the Sumatran Rhinoceros is now extinct in the wild in Borneo, but it is certainly a contributing one.
Rainforest, Sepilok, above and below.


Rainforest anywhere carries its challenges for birders - and I had to rely on my own resources for bird identification, and of course didn't know the calls - but for some reason Borneo seems to demand especially hard work to find birds. It seems that although the diversity is undoubtedly there (over 670 species recorded), overall numbers are strangely low. Various theories have been offered, but none of them seem very convincing; it really is quite odd.

It's not just rainforest either; it's strange to see no lapwings along roadsides, no kites or vultures overhead and no ducks. (They exist, but I saw one flying overhead in my entire time there.) Gardens,even near rainforests, are also surprisingly quiet.

In addition to the lowland forests shown above, there are montane forests on the mountain ranges too.
Lianas in montane forest, Kinabalu National Park Headquarters (1560 metres above sea level).

Chestnut-hooded Laughing-thrush Garrulax treacheri, a widespread and most attractive
bird of the montane forests.
Rajah Brooke Birdwing Trogonoptera brookiana, also at the Kinabalu NP HQ.
An incredibly dramatic inhabitant of the dark rainforest where the electric blue shines against the
black of its forewings.
(I am actually a little perplexed by this one; it is described as having 'electric green' flashes on the wings and this looks more like T. trojana, but that is endemic to the Philippines. Any pointers gratefully received!)
 Higher up still are the misty cloud forests; the best-known - and some of the best - examples are to be found on Mount Kinabalu, but we were there only days after the tragic earthquake and landslides closed the upper mountain for months.
Mount Kinabalu above Kundasang; the scars on the slopes mark where landslides destroyed the forests.
Cloud forest on Gungung Alab, Crocker Range, Sabah.

Bamboos in the same cloud forest.
A diverse understorey including ferns, orchids and lycopods on Gungung Alab.
Scattered around the coast are low-nutrient peat swamp forests, which are low in wildlife diversity even by Bornean standards, but which have their own specialist species.
Klias Peat Forest, Sabah.
Among the specialties of these nutrient-poor soils are the wonderful pitcher plants, which supplement their nitrogen intake by trapping and digesting small animals (which can include smaller vertebrates).
Nepenthes bicalcarata, Klias Peat Forest.
These amazing plants warrant - and will receive - their own posting in due course, but briefly,
the pitcher forms from an extension of the leaf mid-rib beyond the end of the leaf.
The lid keeps the liquid within from being too diluted; it is both sweet to attract insects, and with surface
properties that prevent insects from climbing out.
Moreover the inside is coated with waxy material almost impossible to climb, and the rim can
have downward-pointing spikes around it. The liquid is not digestive; the victim simply drowns and decomposes.
Borneo is pretty much the world hot-spot for them.
Adjoining the peat forests are mangroves, almost all around the coast (originally at least).
Mangroves, Pulau Tiga, an island off the coast of Sabah.
Proboscis Monkeys, among many other species, are mangrove specialists.
For the traveller - including naturalists - infrastructure is generally good, with an excellent road system and good hotels and lodges. People are friendly and food is excellent. By western standards things are pretty cheap, at least away from the tourist honey-traps. For some strange reason, though Sabah and Sarawak are just two states of the same country, travelling between them involves all the rigmarole of international travel, including having passports stamped by immigration officials; allow time for this!

Well, I think that will do for an overview; more detail in weeks to come. But if the opportunity arises to go there, please seize it!

BACK ON TUESDAY

Wednesday, 24 June 2015

Iridescence Without Feathers

This is the third and final in this series of iridescence in animals; the first two dealt with birds, but this time I want to look at other animals - mostly invertebrates but with a fish and a lizard thrown in. The principles are exactly the same as in feathers, with layers of cells underlain with melanin reflecting light from bottom and top surfaces such that they reinforce or cancel each other, giving gleaming colours like polished metal or glass. 

Beetle carapaces seem particularly suitable for the task - or maybe it's just that there are so many beetles!
This scarab beetle, from along the Tamar River in Tasmania, has to be one of the most
beautiful animals I have ever seen; the glowing colours were spectacular.

Christmas Beetle (because they emerge in huge numbers to eat eucalyptus leaves in high summer),
Anoplognathus sp., Canberra. These are also scarabs.

Scarab on Acacia flowers, Leeuwin Naturaliste NP, south-west Western Australia.
Diphucephala sp. on Acacia dealbata, Tinderry NP, south-east of Canberra.
Wasp, Standley Chasm, central Australia.
Fly, Batang Ai NP, Sarawak.
It's OK, I'd given up on the tea by now anyway!

Unidentified bug - ie Hempiteran - Sceales Bay, western South Australia.
(My thanks to Susan - below - for correcting my previous blunder with this one!)
The iridescence need not be in the body though - many insects have iridescent wings, and butterflies of course feature heavily in the iridescent hit parade.
Pollanisus viridipulverulenta Yeldulknie CP, western South Australia.
Only a small moth, but it absolutely gleams.
One of the brightest lights in the Bornean rainforest, the blue flashing against the black background.
This, in Kinabalu NP in Sabah, is the Rajah Brooke Birdwing Trogonoptera brookiana, I feel sure, though that is usually described as having 'electric green' flashes on the wings.
It actually looks more like T. trojana, but that is endemic to the Philippines.
Butterflies and moths are not the only ones with iridescent wings however.
Scarlet Percher Diplacodes haematodes Standley Chasm, central Australia.
Carpenter Bee, Playa Espumilla, Santiago, Galápagos.
Not much iridescence here, but a few seconds later that changed with a change of position
- see below!
 
Finally, a couple of vertebrates, as promised. Some frogs have the characteristic, but I don't have photos of those. Many fish feature brilliantly flashing silver as they turn, perhaps to help confuse predators.
Barramundi Lates calcarifer, Territory Wildlife Park, south of Darwin.
Most Australians probably regard Barramundi as 'ours', but in fact it is a species found from northern
Australia through south-east Asia all the way to the Middle East.
(Annoyingly I didn't notice the reflection of the Emergency Exit sign at the time!)
Finally, one of the most handsome lizards I know.
This big lizard, in all his breeding finery, is a male Eastern Water Dragon Intellagama (formerly Physignathus) lesueuriiAustralian National Botanic Gardens, Canberra.
I hope this little series has given you some pleasure too. Perhaps something slightly less flashy next time...

BACK ON WEDNESDAY

Saturday, 13 June 2015

Humming with Iridescence

Last time I revelled (as I hope you did) in some birds that flaunt iridescent colours - colours that flash with light, and even change with the angle of viewing. I won't repeat the details of how it works here, but now I want to dedicate this entire post to just one family of birds, the fabulous hummingbirds, a South American group which has spread into North America in relatively recent times. Hummers seem to specialise in iridescence, with rich layers of cells that reinforce reflected and refracted light to magnificent effect.

It's probably a cheek for someone from this side of the Pacific (and with a non-spectacular camera) to be featuring hummers, but I am such a fan that I can't help myself. Hopefully some of these will give you pleasure too. I think these little gems can speak for themselves throughout this post for the most part.

Amethyst-throated Sunangel Heliangelus amethysticollis, Inca Track near Machu Picchu, Peru.
Andean Emerald Agyrtria franciae, Alandbi Lodge north-west of Quito, Ecuador.
Common in the northern Andes, but always exquisite.
Blue-mantled Thornbill Chalcostigma stanleyi, El Cajas NP, southern Ecuador.
A mostly high-altitude bird which shines all over!
Buff-tailed Coronet Boissonneaua flavescens, Bellavista Lodge, north-west of Quito.
A relatively unassuming hummer - until it catches the light.
Collared Inca Coeligena torquata:male (Alanbi Lodge) above and
female (Bellavista) below.
 

Golden-tailed Sapphire Chrysuronia oenone, Wild Sumaco Lodge, north-eastern Andes, Ecuador.
Some of these birds really have big names to live up to, but they seem to manage with ease...
Green Violetear Colibri thalassinus near Cusco, Peruvian Andes.
A widespread beauty.

Green-crowned Brilliant Heliodoxa jacula, Mirador Rio Blanco, north-west of Quito, Ecuador.
A relatively big hummer, and brilliant indeed.

Green-crowned Woodnymph Thalurania colombica, Alanbi Lodge.
Surely one of the most stunning in the glittering constellation of hummers.
Long-tailed Sylph Aglaiocercus kingii, San Isidro Lodge, Ecuador (above)
and Violet-tailed Sylph A. coelestis, Sachatamia Lodge, north-west of Quito.
This stunning species pair evolved on opposite sides of the Andes, east and west respectively, from a common ancestor; this phenomenon is one reason that the northern Andean countries
are so fabulously rich in natural diversity.


Purple-bibbed Whitetip Urosticte benjamini, Alanbir Lodge, is limited to the northern Andes.

Rufous-tailed Hummingbird Amazilia tzacatl, also at Alanbi.
A very common hummingbird from Mexico to southern Ecuador, but who could ever tire of them?
Velvet-purple Coronet Boissonneaua jardini, Sachatamia Lodge, north-west of Quito, above and below.
This is one of the most iridescent of all hummers - a big claim, and not really borne out by these photos
taken on a dull wet day. But compare the wing edges and thighs in the two photos to see how the iridescence
'switches on and off'.

 

Violet-bellied Hummingbird Juliamyia julie, Umbrellabird Lodge, southern Ecuador.
There is no bad way to end a posting on either iridescence or hummers
and I reckon this bird emphasises that. Wow!
Thanks for staying with me through a fairly self-indulgent post and one without a lot of extra information - this cast doesn't need help though.

Next time I'll finish this mini-series by looking at iridescence in other animals, mostly invertebrates.

BACK ON WEDNESDAY 24 JUNE (WHEN I'LL BE BACK AT MY DESK!)

Wednesday, 3 June 2015

Living Rainbows; animal iridescence

This is another in the sporadic series on colour in nature. You can find the most recent one here and trace it back therefrom. However for this particular installment you might also like to cast a glance at the first posting on blue in nature; the reason for this is that iridescent colours - where parts of an animal appear to shine, and even to change colour with a slight change of viewing angle - are formed in somewhat similar ways to blue (and combinations of blue, such as give yellow and purple). The colours have nothing to do with pigments, but are down to structures in the feather or skin of the animal, which reflect certain wavelengths.

However while non-iridescent blue for instance is always the same blue from any angle, iridescent structures give varying colours and rely on layers of cells that have different light-reflecting or refracting properties. We see the different colours by looking at different angles, and seeing light coming from the different surfaces. Moreover subtle aspects of these adjacent layers can cause effects to be reinforced or neutralised. Iridescence relies crucially on a reflecting base layer of melanin, or the light just keeps going through. 

An oil layer on water produces similar effects, with light reflecting back from the bottom surface and the top one, creating a rainbow effect as light wavelengths suppress or reinforce each other. (The word is based on Greek iris, a rainbow.)

For a more thorough analysis of the basis of the phenomenon in nature, this is a very comprehensive review.
Iridescent speculum in the wing of the Australian Pacific Black Duck Anas superciliosus.The photos above and below were of the same bird, taken just seconds apart.
 

It seems that iridescence can be used by species to convey information about the individual which includes sex, age, fitness as a mate, fitness to defend territory against an intruder and even species identification for very similar species. It may also play a role in camouflage (breaking up outlines, or in underwater situations), scare or confuse predators, for instance by making it hard to judge the exact distance to the prey, or by alternately flashing and hiding wing patterns in flight. Blues, purples, greens and bronze dominate iridescent colours.

But for the rest of today, let's just enjoy some examples of iridescence in bird feathers - leaving aside for now just one very important family which employs iridescence so comprehensively that they warrant their own posting next time. Let's continue with ducks, which are significant employers of the technique, on heads and backs as well as in wing speculums.
Feral Mallard Anas platyrhynchos, Canberra.
Chiloé Wigeons Anas sibilatrix, Puerto Natales, Chile.
The male is on the right.
Male Muscovy Duck Cairina moschata, Manu NP, Peru.
Even in the dull rainforest light which is my excuse for a poor photo, the iridescent back gleams.

Mandarin Duck Aix galericulata, Taronga Park Zoo, Sydney.
The most widespread ibis in the world is the iridescent Glossy Ibis Plegadis falcinellus, but it is not the only iridescent ibis. 
Glossy Ibis, Jerrabomberra Wetlands, Canberra.
Hadada Ibis Bostrychia hagedash, Queen Elizabeth National Park, Uganda.
A very familiar African bird, named for its compellingly loud call.
Austral Parakeet Enicognathus ferrugineus, Cuevo del Milodon, southern Chile.
The lightly iridescent head of this parrot is found further south than any other parrot's,
to very tip of South America.
Pigeons also feature impressive iridescence, mostly in the wings in Australia at least.
Common Bronzewing Phaps chalcoptera, Canberra.A very common bird, including in urban situations, across most of Australia.
Crested Pigeon Ocyphaps lophotes, displaying in central Australia.
Another very common and familiar bird which probably thereby often fails to receive the admiration it deserves
(though this one wasn't interested in human admirers!).
Spinifex Pigeon Geophaps plumifera, central Australia.
The similarity of the display of these two species is striking.
Squatter Pigeon Geophaps scripta, Mareeba, Queensland.

Common Starling Sturnus vulgaris, Canberra.
An unwelcome exotic here, but the green to purple iridescence of the breast is still striking.
Greater Blue-eared Glossy Starling Lamprotornis chalybaeus, one of the
many stunningly iridescent African starlings.
Ethiopian Swallows Hirundo aethiopica, Waza NP, northern Cameroon.
Many swallows show such iridescence.
 
The green iridescent sheen of the wing covers of the male Great Frigatebird Fregata minor is one feature that distinguishes it from similar species. Here on Genovesa, Galápagos.
Leaden Flycatcher male Myiagra rubecula, Canberra.
This familiar bird catching the light took me by surprise; in most lights it's a more sombre and well, leaden colour.

Malachite Kingfisher Alcedo cristata, Lake Mburo NP, Uganda.
Kingfishers also commonly display iridescence, but I especially love the highlights of this one.
Masked Flowerpiercer Diglossa cyanea, Yanacocha Reserver, Ecuador.
These lovely birds 'cheat' by stabbing the base of a flower to steal nectar without
offering pollination services.
Shining Bronze-Cuckoo Chrysococcyx lucidus, Canberra, one of the world's smallest cuckoos.
All bronze-cuckoos have the strikingly iridescent wings.
Superb Fairy-wren Malurus cyaneus, Canberra.
One of south-east Australia's most familiar and loved birds whose iridescence
is often not recognised - until the sun catches them and 'flash'!
I hope this has brightened up your day a little, as preparing it has mine.

I'm off again for a couple of weeks, but will then be back for a while with hopefully lots of natural history blogging material.

MEANTIME I'LL LEAVE SOMETHING MORE FOR YOU ON IRIDESCENCE, FEATURING THE AMAZING HUMMINGBIRDS, ON SATURDAY 13 JUNE.