Sometimes Nature Really IS Black and White! #1

Maybe it doesn't happen to you, but I often find I'm not really in control of what I write. OK, you may well agree that you've noticed that, but what I actually mean is that I sit down with a topic in mind, and it takes over and turns into something else. You may recall that two days ago I set out to do a simple posting on black organisms; in the process I found myself foreshadowing an additional posting on 'black-and-a-colour' organisms. When I started that, an annoying little voice said "actually, there's a whole posting to be written on black and white creatures alone". And then, for goodness sake, it started to suggest that that posting could, and should be sub-divided...

OK, who am I to argue? The first point to remember is that much of the world doesn't actually see colours as we understand them. I don't want to go too far into this here, but where we humans have three pigments in the colour-viewing cone cells of our retina, birds have four or even five, and they are different from ours, so they see 'different colours' from us - effectively they have four or five primary colours, and we wouldn't call them red, blue or yellow! That's getting close to philosophy rather than biology, but it's certainly relevant. At least some reptiles and fish also have four cone pigments (many haven't been examined). On the other hand, among mammals only primates and hoofed mammals appear to see colour. In an animal which doesn't see a range of colours, black and white is certainly a striking contrast; the same is true of animals like us which do see other colours however. The prevalence of black and white patterns among birds, which probably have the most sophisticated colour vision of any animals - certainly of any vertebrates - is testament to its effectiveness.

Pied Butcherbird Cracticus nigrogularis, Bourke, New South Wales.
Butcherbirds are never shy and retiring!

So, being pied (ie black and white, the word coming for an old English word for the European Magpie) is a good way to stand out; it's a warning, eg "I'm tough and stroppy and staying clear is the best way to deal with me." The Pied Butcherbird is a member of an Australian family of mostly large, self-confident species, mostly black, white and grey, which don't at all mind being visible - they can definitely look after themselves.

A very well-known member of the family is the Australian Magpie Cracticus tibicen, famed for its fearless defence of territory during breeding season. Its personality makes it a very successful urban bird; a few males, which apparently had bad youthful experiences, every year terrorise their neighbourhood.

Black-backed Magpie, Canberra. No bluffing involved!

Australian Magpies belong to the family Cracticidae; other large in-your-face black and white members include the currawongs, that were the subject of one of the first postings of this blog. Our Magpies were named of course from a superficial similarity (which doesn't really go much past being black and white!) to the Eurasian Magpie Pica pica.

Magpie, Barcelona (it was very early in the morning!).
These are a true crow, family Corvidae.

Almost inevitably, black and white birds, of any size, are bold and even pugnacious in defence of their nest. Indeed sometimes they almost appear to have an excess of testosterone at any time...

Common Fiscal Lanius collaris, Cameroon.
This is a large conspicuous shrike, found throughout most of sub-Saharan Africa.

Magpie-lark Grallina cyanoleuca, Longreach Queensland.
This is a large aberrant monarch flycatcher, whose pugnacity often extends to its own reflection.

Willie Wagtail Rhipidura leucophrys.This fantail (family Rhipiduridae) is small but entirely fearless, including taking on any of the
Australian Big Black-and-White Boys featured above!

African Pied Wagtail Motacilla aguimp, Murchison Falls Uganda,
another conspicuous bold small bird.

African Paradise-Flycatcher Terpsiphone viridis, Benoue National Park, Cameroon.
This is yet another stand-up-and-be-seen flycatcher, but I'm partly cheating in that this is
a colour variant (but a regular morph rather than a 'freak') of the more usual chestnut plumage.
It's a great bird though!

American Oystercatcher Haematopus palliatus, Isla de Chiloé, Chile.
Oystercatchers are either black or pied, and make no attempt at hiding, except when breeding.

White-cheeked Honeyeater Phylidonyris niger, Lesueur National Park, Western Australia.
Members of this genus are especially aggressive and direct in defence of 'their' flowering bush.

Chequered Swallowtail Papilio demoleus, Muttaburra, central Queensland.
This is a widespread species known by other common names elsewhere in the world.
Interestingly it is described as 'aggressive' (to other butterflies) so I've included it here.

But there may be other reasons to avoid an animal than simple belligerence; it might be toxic or have other chemical defences. The most famous of these are doubtless the American skunks, which spray mercaptans and other foul-smelling sulphur-based chemical from anal glands. They don't want to waste their investment however, so the colour is a warning to back off.

Patagonian Hog-nosed Skunk Conepatus humboldtii, Strait of Magellan, Chile.

Other, smaller animals, contain toxins - some of the species must die in the predator's learning process, but then others will be left alone. In not all small black and white animals is the toxicity proven, but it usually turns out to be the case.

Black and White Tiger Moths Spilosoma glatignyi, Big Badja Mountain, southern New South Wales.

Pierid butterfly, Bwindi Impenetrable National Park.
I bet it's toxic too, but I haven't tried it...

And on that dodgy note, I'll leave it for now. But as I flagged above, I'm coming back to this one very soon, because black and white can also be a way of avoiding attention, or of attracting it for reasons other than threats. Hope to see you then...

Back Friday.

Black Thoughts

Last month I foreshadowed an occasional series on colours, starting with white. It seems logical that the next instalment should be white's opposite - black. While white is produced when all wavelengths are reflected, a black surface is one that absorbs all light; when essentially no visible light from a particular source reaches our eye, our brain says 'black'. This is achieved by particular combinations of primary colours, or by black pigments. In nature, dark colours - blacks, greys, browns - are generally formed by varying concentrations of a family of chemical pigments called melanins, and particularly eumelanins.

There are various reasons for being black. Dark surfaces absorb heat, which may be valuable to 'cold-blooded' animals in particular. Melanins are valuable in protecting against ultra-violet light, having the chemical ability to convert UV radiation energy into heat. Melanins also provide resistance to wear in feathers, so wing tips of soaring birds are often black. 

Black Crowned Cranes Balearica pavonina, Waza National Park, northern Cameroon.
The wear-resistant black tips to the flight feathers are obvious.

In combination with other colours - especially white, red or yellow - it can be very conspicuous, and form a warning pattern, or can help in breaking up a body outline and provide camouflage! This last aspect, of 'black in combination', we'll turn to on Wednesday. Today, just black... (Though having said that, it will be noticeable that in many of the following examples, there will be contrasting colours in other body parts.)

Black Vulture Coragyps atratus, Isla de Chiloé, Chile.
Perhaps black helps soaring birds keep warm at high altitudes?

African Black Crake Amaurornis flavirostra, Queen Elizabeth National Park, Uganda.

Sooty Oystercatcher Haematopus fuliginosus, Murramarang NP, south coast New South Wales.
Though similar to black oystercatchers elsewhere in the world, this one is endemic to Australia.

Dragonfly, Murchison Falls NP, Uganda.
Sorry, no further information!

Native Bee on paper daisy, Xerochrysum, Canberra.

Little Black Cormorant Phalacrocorax sulcirostris, Canberra.
Cormorants have no water-proofing feather oils, to assist them in diving; as a result they must
spend time hanging their wings out to dry, in which black might help by absorbing heat.

Pale-eyed Blackbird Agelasticus xanthophthalmus, Manu National Park, Peru.
Not related to the European Blackbird, which is a thrush, the American Blackbirds, family Icteridae,
are restricted to the Americas.

Sun Bear Helarctos malayanus, Perth Zoo (sorry, it was the only one I have!)
Aberrant melanistic forms aside (eg black leopards or jaguars) there are not many black mammals.

Mountain Gorilla Gorilla beringei beringei, Bwindi Impenetrable National Park, Uganda.

Shingleback Lizard Tiliqua rugosa, Goorooyaroo NP, Canberra.
A large aberrant skink, Shinglebacks are found across inland Australia. Mostly yellow-brown, here
in the southern highlands at the cold edge of their range they are glossy black to make the most of the limited sun.
(This one was dusty!)

Black Kangaroo Paw, Macropidia fuliginosa, Lesueur NP, Western Australia.
Not many black flowers to choose from, hence this ancient and faded slide; sorry!

Tarantula (under the seat we were napping on!), Blanquillo Lodge, Peruvian Amazonia.
Oddly, as far as I can determine, spiders don't have melanins!

Back Wednesday, with some black-and-coloureds.

On This Day, 5 January; the big wet

As I write this, it's 38 degrees C outside (and in my study!), about 10 degrees above our long-term average maximum for January. In many places in south-eastern Australia it's well over 40 at present. There's not much rain around, and numerous fires are burning. From down here it's hard to imagine that on this day in 1979 Mount Bellenden Ker, behind Cairns in tropical Queensland, received 1140mm of rain in 24 hours! That month they got 5387mm (ie over 5 metres); their annual average is 8500mm. (Across Australia the average is 165mm...) Mind you, parts of the western slopes of the Andes in north-west Ecuador and south-west Colombia get double that each year.

The mountain was named by Phillip Parker King, for a curious character called John Bellenden Ker, editor of the Botanical Register in London. He was born John Gawler, but at the age of 40 sought and received royal permission to change his name to John Ker Bellenden; having achieved his odd aim, he proceeded to call himself Bellenden Ker... Please don't ask me. He did however get this rather nice Tasmanian shrub named for him.

Bellendena montana, family Proteaceae, Ben Lomond NP, Tasmania.
These are the fruit.

Meantime we await a bit of rain - not a metre preferably! - down here.

Spotted Catbird, (near!) Mt Bellenden Ker.

Back Monday.

Australia; a backwater for backfangs

We have long known that Australia is fundamentally different from the rest of the world with regard to its mammal fauna and its flora. More recently we've accepted that the majority of our Passerine bird fauna is also uniquely Australian. However an aspect of our biota that is not often discussed in this regard is that the composition of our venomous snake fauna is entirely different from the rest of the world. As ever, we can explain it by seeking to understand the bigger picture. 

Some background to snake evolution first. The oldest snake fossils appear to be some 120 million years old, from Algeria. The question has been vigorously debated, but the weight of evidence seems to be swinging towards a burrowing lizard as the ancestor. Snake bones are small and fragile, so the fossil record is not as strong for snakes as it is for most other vertebrate groups, but for some 80 million years python-like or boid-like animals dominated the snake world. Then, around 35 million years ago a group of smaller, quicker snakes arose, though played only a minor role until the world began to cool about 20 million years ago, a situation which didn't suit the boids. From then these Colubrids began to dominate, until now they comprise some two thirds all the world's snakes, over 1900 species. Indeed in much of the English-speaking world they are referred to as 'typical snakes' - not in Australia though. Along the way (perhaps 15 million years ago) they developed large rear teeth which had grooves down the outer edges, along which ran modified saliva that acted as pacifying venom on prey which objected to being eaten. 

Unidentified colubrid, Manu National Park, Peruvian Amazonia.
This fellow was encountered on a river beach at night. Any identification help gratefully received!

Tree Snake, Limbe Botanic Gardens, Cameroon.
I think this one is Thrasops batesii, but again advice welcomed.

Striped Bronzeback Tree Snake Dendrelaphis caudolineatus, Sabah.

 Not long after the venomous back-fanged Colubrids arose, a new group also appeared on the scene. In this group the venomous fangs moved to the front of the jaw, reduced in length and closed around the venom-delivering grooves, to form hollow hypodermic syringes. These Elapids were the ancestors of most of the most venomous living snakes; cobras, mambas, coral snakes, sea snakes - and most of the familiar Australian species, such as brown snakes, taipans, copperheads and black snakes, among which are the world's most venomous species. However, there are only about 320 species, roughly 10% of the world's snakes.

Tiger Snake Notechis scutatus, Twin Creek Reserve, Western Australia.

 The situation in Australia is dramatically different from the rest of the world. Here, the 120 Elapids represent two thirds of the snake world, while there are only 10 Colubrids, the best known of which are the Brown and Common Tree Snakes.

Common Tree Snake Dendrelaphis punctulatus, above and below.
 Above, 'Golden Tree Snake' Kakadu NP, Northern Territory.
Below on Daintree River, north Queensland.
The colour variation in this species is remarkable. Another familiar form is green.

The answer to this apparent conundrum is basically down to chance. Both groups arose in the Northern Hemisphere while Australia was isolated; it was the Elapids which made their way here when Australia got close enough to Asia, and in a continent empty of competition they spread to an extent that hadn't been possible elsewhere. By the time Colubrids made the journey, most of the good niches were gone.

The most recent group of snakes to arise, the Vipers, appeared about 10 million years ago. They have very long front fangs, to inject their venom deep into prey. Indeed, the fangs are so long that they must rotate back, to fold away along the roof of the mouth. They haven't yet found their way to Australia.

forest viper, Bokassa Mountains, Cameroon.
Again, I'm afraid I can't provide identification.

So, Australia, the land of marsupials, of banksias, of honeyeaters - and elapids.

... and the Sun Rises on 2013

Well, maybe it's a bit predictable, but it does seem appropriate to complement my symbolic sunsets from last time with some equally symbolic sunrises to mark the beginning of what I hope will be a bright new year for us all. As you'll see, I'm fond of sunrises over water. I hope I'm permitted to also include a couple that were actually taken pre-sunrise, in the first grey preludes to dawn. And at least this time I don't have to specify that I haven't been to all these places this year...

Lake Cargelligo, New South Wales; not smoke, but fog on this big inland water storage - natural, but now regulated.
I liked the Black Kite drifting through. (For more on this area see this earlier blog.)

Lake Edward, Queen Elizabeth NP, Uganda.
I confess that this was the view from the breakfast area.

Across Cocha Anangu, Napo Lodge, Yasuni NP, Ecuador.
This is a superb lodge, run by the Anangu Quichua community.

Streaky Bay, west coast of South Australia.
It's unusual of me to include structures in such pictures, but this time there wasn't much choice.

Volcano Corcovado, southern Chile, taken from the sea.
The ferry trip from Puerto Montt to Puerto Chacabuco (about 20 hours) is superb;
I'll feature it in a future blog.

Table Mountain (of course!) but taken from the north, which isn't the most familiar view of it.

Cocha Salvador, Peruvian Amazonia.

Pre-dawn on Mount Kupe, western Cameroon.
The day spent birding up the mountain was among the most memorable and exhausting I've spent.

Machu Picchu, Peru, from below, in pre-dawn mist.

Sunrise over Ruhija, Bwindi Impenetrable National Park, western Uganda.
The start of another superb day, in primary rainforest.

 Now the sun is well and truly up, and next time I'll try to bring you something a little more substantial!

Back Friday.

As the Sun Sets on 2012...

It is traditional to review the year that is about to slip below the horizon (as my friend Martin from The House of Fran_Mart has done so comprehensively here), and I was tempted to do so, but in practice I've been working most of the day (preparing the index for a forthcoming book on Australian bird names) so I'm going to settle for some symbolic sunset shots from a variety of places. I haven't been to all these places this year!

Blanquillo Lodge, Peruvian Amazonia.
The highlight here is undoubtedly a fabulous parrot lick, but sunsets over the cocha are also a feature.

Kata Tjuta, central Australia.
You may know it as 'the Olgas', but we haven't called it that here for some time.

Waza National Park, northern Cameroon.
The Sahel is a harsh landscape, and under threat, but still beautiful.

Blackburn Island, off Lord Howe Island.
We had a delightful week on Lord Howe early this year - you've not heard the last of it!

Volcan Chacabuco, over Puerto Montt, southern Chile.

Darwin, Northern Territory of Australia; the Timor Sea hosts excellent sunsets!

Sacha Lodge, eastern Ecuador.

Lake Mburo National Park, Uganda.
Later that night there were lions around my suddenly flimsy-feeling fixed tent;
they're not supposed to be there, but of course I was glad they were. In principle...

May 2012 end happily, and 2013 dawn bright and hopeful for us all. I look forward to sharing some of it with you; my thanks for coming with me this far.

Back on Wednesday.