Camouflage #2; spinelessly hiding

Last time I introduced the concept of camouflage in nature by looking at some vertebrates - mammals, birds, reptiles and frogs - which have evolved some superb patterns, shapes and postures to disappear into the background. As promised, today I'm going to continue the theme by putting the magnifying glass onto some smaller animals, invertebrates - if I can find them!

Camouflage is for the benefit of both hunters and hunted, and small animals are always potential prey, irrespective of whether they are also hunters themselves. The first few examples then are of animals which live by catching other animals, but they must also stay out of sight from the myriad of larger animals, vertebrate and invertebrate, which would devour them if given a chance. The first is one of my favourites - and I will confess that I saw it only after photographing the flower!

The flower spiders, Diaea spp., family Thomisidae, comprise some 80 species of specialised Crab Spiders,
found on every unfrozen continent, with over 30 of them native to Australia.
They lurk in and around flowers, aided by cryptic colouring (ie often brightly coloured!), and hook
unwary pollinators with their curved front legs.
This one, in the National Botanic Gardens in Canberra, is hiding, albeit in the open,
on a common local daisy, Chrysocephalum semipapposum.

A Western Australian crab spider, probably Diaea sp., on, appropriately, a spider orchid,
Caladenia (or Arachnorchis) longicauda.
The characteristic powerful jagging two front pairs of legs are obvious here.

Spiders which hunt elsewhere must also hide, including those which guard a web; a spider in a web in the day is very vulnerable to birds in particular. This one was beautifully camouflaged on the tree bark at the edge of its web.

Eriophora transmarina, family Areneidae, Gungahlin Hill Nature Reserve, Canberra.
The pattern is surprisingly reminiscent of the Tawny Frogmouths, hiding against an identical background,
that featured in my last posting.

And the spiders which do not ambush or build webs, such as the ground-ranging wolf spiders, must also take care not to be conspicuous from above.

Wolf Spider, family Lycosidae, White Dam Conservation Park, South Australia.
The dark patches resembling shadows, and the grey legs and abdomen, break up the outline superbly.

Praying Mantises, like the flower spiders, often hide in foliage or by flowers to trap pollinators; here too resembling the background colour is a big help.

It worked for this one, which is munching on a small fly!
Corang River, east of Canberra.

If you're a grasshopper or moth however, there is no question where you come in the food chain, and while it's not the only defence, camouflage can only help. Here are some examples that impressed me.

This grasshopper, in stony country near Broken Hill, western New South Wales, would have made my point better,
and been a lot safer, if it had stayed on the paler rocks, but you can see how well it would vanish there.

This beauty, in a granite landscape in Torres del Paine National Park, Chilean Patagonia,
was doing a much more convincing job.

As was this one north of Maroua, in the Sahel of Cameroon.
It is also an excellent example of the importance of orientation.

The camouflage of this beautifully mottled Hamadryas sp., above and below,
works equally well on different backgrounds.
Cerro Blanco Reserve, Guayaquil, Ecuador

 

Like the Broken Hill grasshopper above, this lovely moth wasn't on the perfect background for its pattern, but we can imagine the effectiveness if it was on a licheny tree trunk as above.

San Pedro area, Rio Madre de Dios, Peru.

A variant is to suddenly 'vanish', by flashing coloured legs (some grasshoppers) or wings (some butterflies and moths) in flight, and suddenly hiding them on alighting. The simultaneous appearance of a big eye is an additionally unnerving experience for their puzzled pursuer!

Owl Butterfly, Caligo sp., family Nymphalidae, Sacha Lodge, Ecuadorian Amazon.
Above and below.

Insect larvae are of course even more vulnerable, and many caterpillars try to stay hidden while feeding in the open.

Caterpillar on Snow Gum twig, Namadgi National Park, near Canberra.

And finally for today, it's not just land vertebrates that need and adopt camouflage, though I'm not in a position to record these for the most part. This crab however, photographed from a mangrove boardwalk, really caught my attention only when it moved.

Huskisson, New South Wales south coast.
See how perfectly the carapace pattern matches that of the sun of the sand grains!

Ghost crab, Tempurong Beach, Sabah.
This one was aware of me being too close and was moving, but flat against the sand it disappeared.

 I've had fun with this, and I hope you have too. Back next time with something completely different; something for the Gunn lobby!

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Camouflage; hiding in the open

Much has been written on the topic of camouflage in nature, and I don't have the access or the equipment to show you some of the truly marvellous examples in nature that I'm sure you've seen on the telly. However, maybe you'll enjoy some of the examples that have come my way over the years; they represent some of the most wonderful - and I use that word both advisedly and often with regard to nature - examples of evolutionary adaption imaginable. 

Several approaches to camouflage are recognised. (The word incidentally comes to us straight from the French camoufler, simply 'to hide' or 'deceive'. It only appeared in English, for reasons unclear to me, during the First World War, referring to military applications.) The two most widespread in nature involve firstly breaking up outlines by use of bold and irregular patterning, and secondly blending into the background by matching colours, minimisation of shadow, and/or an overall posture and shape resembling an 'uninteresting' object.

And camouflage works remarkably well for big animals as well as small ones; there is nothing quite like the shock of realising - preferably from within a vehicle - that that movement is the flick of an elephant's ear, and that it is attached to an elephant, and that there is a whole herd all around. (Not that I can suggest why an elephant needs camouflage!)

Context is critical. An animal which disappears into its environment is entirely conspicuous out of that context, as the following examples demonstrate.

Sumatran Tiger Panthera tigris sumatrae, Adelaide Zoo.
No missing it here, but in dappled shade among grass and shrubs, it can disappear as its outline vanishes.

Coiled among foliage, this green tree snake Thrasops batesii (Limbe Botanic Gardens, Cameroon)
would not be nearly so obvious.

Titan Stick Insect Acrophylla titan,  Nowra, New South Wales south coast.
Among foliage or twigs this superb monster - some 20cm long - would effectively vanish.

For the rest of this posting I am going to focus on vertebrates; don't be too exasperated, this is merely because I have too much material for one posting, and I will make sure our invertebrate friends get their full due next time!

The examples above represent two predators and one potential prey; both roles can require camouflage, for evident and complementary reasons.

Most of the following examples employ their camouflage with the intention of not becoming someone's dinner, though in the case of the lizards and frogs for instance (and the tree snake above) they play the role of both dinner and diner in different situations.

One group of animals which needs effective camouflage comprises nocturnal birds, many of which roost in the open during the day. As such they are certainly vulnerable to direct predation, but owls in particular are also unmercifully harassed by diurnal birds, who know perfectly well that at night the owl is a very dangerous neighbour and would rather it slept and woke somewhere else entirely. Tree-roosting species have evolved some superb resemblances to tree bark, with perfect patterns of cracks and fibres.

Tawny Frogmouth pair Podargus strigoides, south of Canberra.
While they have chosen to roost by an inappropriately smooth trunk, they match the branch they're on.
If concerned - and these weren't - they will stiffen and pull in the feathers to look remarkably like a broken branch.

Tawny-bellied Screech-Owl Megascops watsonii, Amazonia Lodge, Rio Madre de Dios, Amazonian Peru.
Again, perhaps not the ideal situation, but imagine if that underside was alongside a tree trunk,
rather than in the bamboo clump that it has chosen.
Note the slightly open eye, just checking on me...

And while looking at creatures wanting to be mistaken for lumps of tree, how about the sloths, which are permanently at risk in the canopy from large eagles?

Brown-throated Three-toed Sloth Bradypus variegatus, Puerto Maldonado, Peru.
Had I not zoomed in and centred on her, this animal (two actually, if you look closely at her belly)
would not be at all obvious.

 OK, so maybe these examples aren't convincing you, though I can promise that in the right situation they are remarkable, but the ground-roosting nightjars are something altogether else! Try this one - a Standard-winged Nightjar Macrodipteryx longipennis at Ngaoundaba Ranch, central Cameroon - before looking at the clues in the caption.

How did you go? If it weren't for the extraordinary wing standards (resulting from a hugely elongated central feather shaft, much of which is bare) this would be impossible. The dark patches are the standards - look closely and you can see the bare shafts. In front of the one on our left is the bird's head, looking to the left. Now you can fill in for yourself!

Some frogs are pretty good at it too.

unidentified tree frog, Manu National Park, Peru.
This a night photo, when the frog doesn't need to hide, but in the day imagine those remarkable skin patterns
against a mottled tree trunk.

Engystomops freibergii Tambopata Research Centre, southern Peruvian Amazon.
This one is superb!

 Lizards, like frogs, are both hunters and hunted and many adopt camouflage accordingly.

Lined Earless Dragon Tympanocryptis lineata, Bladensburg NP, central Queensland.
Beautifully hidden among the ochre and rust colours of its arid environment.

The dragon lizard family, Agamidae, is also widespread in Asia and Africa; unsurprisingly, agamids in similar habitats in these continents adopt similar camouflage.

unidentified agamid, north of Maroua, northern Cameroon.

Common Gliding Dragon Draco volans, Gomantong Caves, Sabah.
The matching of its pattern to the lichened tree trunk is remarkable.

In the Neotropics there are no agamids, but there are plenty of Anolis lizards (family Anolidae or Iguanidae, depending on your taxonomic preferences). Here the priority is more likely to be towards hiding in the greenery.

Green Anole Anolis chloris, Mindo Valley, Ecuador.

Young animals are especially in need of camouflage, especially before they are able to accompany their parents or, in the case of birds, able to fly.

Common Potoo chick Nyctibius griseus, Sacha Lodge, Ecuadorian Amazon.
In this case it really isn't obvious where branch stops and chick starts!

Dusky Woodswallows Artamus cyanopterus (family Artamidae, nothing to do with 'real' swallows), east of Canberra.
They nearly always nest in such a situation, in tree forks or hollow stumps or spouts,
where bark-like camouflage is also important.

But even before the chicks, eggs and even nests must be hidden from predators.

Patagonian Tyrant Colorhamphus parvirostris on nest, Alerce Andino National Park near Puerto Montt, Chile
We can just see the parent peeping over the top of this beautifully disguised nest; this nest, I am told, is not often seen, not least, I am sure, because of the lovely camouflage of mosses and lycopods.

Egg of Red-capped Plover Charadrius ruficapillus, Comerong Island, south coast New South Wales.
Many ground-nesting shore birds have done away with nests altogether, as being too conspicuous.
Here the egg resembles a stone to a remarkable extent.

Next time, I will conclude this mini-series by looking at some pretty impressive invertebrate disguises.

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South American Monkeys; wonderful and mysterious

Anyone who has stepped into a South American forest and become aware of monkeys peering quietly down or crashing in noisy gangs through the foliage will have felt their wonder. And yes, maybe mine is heightened by coming from a continent where there were never any native primates until the coming of people just some 50,000 years ago. I first encountered the thrill of wild monkeys in Africa (I'll never forget the moment in late afternoon in Windhoek, Namibia, looking down at a railway line and noticing the pack of dogs crossing the line - and suddenly realising they were baboons!), but since then I've seen many more, of species and individuals, in South America.

Male Grey Woolly Monkey Lagothrix cana, San Pedro area, Manu National Park, Peru.
(I confess to finding photography of dark animals in the canopy a challenge!)

The mystery is how they came to be there. Most extant South American mammals originated in North America, arriving in the last very few million years when the Isthmus of Panama arose and allowed two-way movement; all South American hoofed mammals and carnivores arrived this way. However there is no evidence of monkeys having ever existed in North America (unlike camels for instance, which arose there, dispersed, then became extinct in their homeland). Further, the fossil and genetic evidence points firmly to an origin of some 35 million years ago, when the two modern American continents were nowhere near each other.

Genetic evidence also makes it clear that South American monkeys (like the old South American rodents, such as guinea pigs, capybaras and viscachas) arose in Africa, so it seems that at a time when the Atlantic was narrower (though still most of 2000km across) a small band of unwilling monkey explorers made what must have been a horrific crossing on a raft of floating vegetation. (There was a highly controversial paper some four years ago which proposed that the monkey ancestors arose some 180 million years ago and were already in situ when the continents separated, but there is no fossil or genetic evidence to support this and it has already largely vanished from the discussion.)

Modern monkeys are divided most fundamentally into those who stayed at home in Africa (or made the more modest overland journey in increments to Asia), and those who crossed the Atlantic. Some of the key characteristics of the Old World monkeys - the catarrhines (from old Greek meaning 'hooked nose') - are narrow nostrils, close together and often down-pointing, and leathery buttock pads for sitting on.

Guereza Colobus Colobus guereza, Queen Elizabeth National Park, Uganda.
Especially if you click to expand the picture, you can see the characteristics of the catarrhine nose
on these two very beautiful animals.

Olive Baboon Papio anubis, Lake Mburo National Park, Uganda.
The useful callouses for sitting on are obvious.
(There is no suggestion that she had anything to do with the bottles before they were emptied!
As indeed didn't I...)

The South American platyrrhines - 'flat nosed' - have open and more widely spaced nostrils, no buttock pads, and most importantly, prehensile tails for grasping, which no Old World monkey has developed.

Ecuadorian Squirrel Monkey Saimiri macrodon, Yasuni National Park, Ecuador.
The platyrrhine nose features are evident.

Colombian (or Venezuelan) Red Howler Monkeys Alouatta seniculus at riverbank clay lick, Manu National Park, Peru,
nicely demonstrating the use of their prehensile tails.

There are five families of South American monkeys now generally recognised, and an interested visitor to the cloud forests and Amazon basin of the northern half of South America has an excellent chance of seeing examples of all five. The species numbers given are likely to increase in coming years, but after some big changes in our understanding in recent years things are starting to settle down again. Allow me to introduce the families, in increasing order of number of species.

* Aotidae, the night or owl monkeys, or douroucoulis, 10 species. These delightful little animals can sometimes be seen basking at the mouth of their communal tree hollow, and inspecting passing visitors. They emerge 15 minutes after sunset (there is virtually no twilight in the tropics) when daytime predators have retired for the day.

Spix's Night Monkeys Aotus vociferans, Yasuni National Park, Ecuador.
They typically live in social groups of up to five members.
Their huge eyes are an obvious adaptation to nocturnalism; while their ancestors had colour vision, typical of most primates, night monkeys have lost it.

* Callitrichidae, squirrel monkeys and capuchins, 16 species. Perhaps the monkeys most likely to be encountered; squirrel monkeys in particular move in noisy groups of up to a hundred, often low in the canopy and stopping to feed at fruiting trees. In such a group of squirrel monkeys, there will be perhaps 20 breeding females and a few breeding males; males play no part in caring for young, but the mothers get help from other females, especially her adult daughters. Capuchins, somewhat larger and less likely to hurl themselves into space, often accompany these foraging parties.

Ecuadorian Squirrel Monkey above, and
below with baby, Yasuni National Park, Ecuador.

 

Spix's White-fronted Capuchin Cebus unicolor, Yasuni National Park, Ecuador.
Taxonomy of capuchins is still hotly debated, and this one is also recognised as a sub-species.
Pretty much any plant matter or small animal, including tree frogs, is grist to capuchins' mill.
The name comes from a supposed resemblance to the garb of capuchin friars.

*Atelidae, spider, howler and woolly monkeys, 25 species. These are the 'typical' large South American monkeys, at least some of which are likely to be encountered.

The territorial roaring of howler monkeys is, to me, the sound of the Amazon, rolling over the forest by day or night, as the big males use an inflatable throat pouch and enlarged jaw bones to produce one of the loudest animal sounds known.

Colombian Red Howler Monkey, Manu National Park, Peru.
They have a large caecum and colon to assist with fermentation-digestion of a leafy diet.

Mantled Howler Monkey Allouata palliata, Manglares Churute Reserve Ecuador.
Here this species inhabits the highly threatened Pacific drier lowland forests.

Grey Woolly Monkey, Manu National Park, Peru.
As well as lowland rainforests, woollies can live higher in the cold cloud forests than do most other monkeys.

Black Spider Monkeys Ateles chamek at riverside clay lick, Manu National Park, Peru.
Sorry, the best I could do! Spider monkeys are characterised by very long slender limbs and tails for swinging along below the forest branches.

* Pitheciidae, uakaris, sakis and titi monkeys, 40 species. Despite being a large family, these monkeys are not so often encountered, at least in areas where I've visited. They tend to be high canopy fruit eaters; sakis, unusually among South American monkeys, do not have prehensile tails.

Monk Saki male Pithecia monachus, Yasuni National Park, Ecuador.
This big male was typically wary, despite being way above our heads. Much of the apparent bulk is actually fur.

Dusky Titi Monkey Callicebus moloch (but I think this one - the species, not this monkey! - has been split up),
Rio Madre de Dios, Peru.
Unlike most primates, titis apparently form long-term pair bonds. They feed quietly and closer to the ground than sakis.

* Callitrichidae, marmosets and tamarins, 41 species, including the smallest, and some of the most threatened South American monkeys. Some 20% of these species have been described in the last 20 years or so, and the number is rising. Groups of up to 20 of these tiny exquisite monkeys roam the canopies, gleaning almost anything they find. From the ground the view can be frustrating, but some will also come down near to our level, to provide some of our most precious memories of the continent.

Graell's Black-mantled Tamarin Saguinus graellsi, Sacha Lodge Rainforest Tower, Ecuador.
Now regarded as a separate species from the Black-mantled Tamarin from further east, this one can often be seen in the gardens of Sacha Lodge.

Golden-mantled Tamarin Saguinus tripartitus, Napo Lodge, Ecuador.
These glorious little animals are a feature of this Quichua community-owned lodge.

A longer than usual posting, but it's a big topic, and I hope as interesting to you as it is to me. No substitute for seeing them for yourself though of course!

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