About Me

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Canberra-based naturalist, conservationist, educator since 1980. I’m passionate about the natural world (especially the southern hemisphere), and trying to understand it and to share such understandings. To that aim I’ve written several books (most recently 'Birds in Their Habitats' and 'Australian Bird Names; origins and meanings'), run tours all over Australia, and for the last decade to South America, done a lot of ABC radio work, chaired a government environmental advisory committee and taught many adult education classes – and of course presented this blog, since 2012. I am the recipient of the Australian Natural History Medallion, the Australian Plants Award and most recently a Medal of the Order of Australia for ‘services to conservation and the environment’. I live happily in suburban Duffy with my partner Louise surrounded by a dense native garden and lots of birds.

Tuesday, 11 March 2014

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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