constructing camouflage: animals that make disguises with local materials
As Summer gives way to the cold season, many animals change out their feathers and fur to match the color shift of the environment, often trading tan for gray and white. Colors and patterns for blending in are ubiquitous among predators and prey alike.
Much rarer though are examples of animals assembling disguises using local materials. The results are uncanny and an ingenious way of disappearing in plain sight.
The assassin bug Acanthaspis petax glues up to 20 dead ants on its back.1 It ranges in east Africa and Malaysia. The cloak is both visual and chemical, allowing it to bypass sentry ants, and also serves as armor. Jumping spiders, which rely on acute vision, were 10 times less likely to attack assassin bugs wearing this corpse shield2.
In the western Pacific, the coconut octopus Amphioctopus marginatus, in addition to color- and texture-changing skin, grabs debris around its vulnerable body, flawlessly blending in to coral reefs and seabeds. Halved coconut shells are a favorite hideout, but a keen predator might be having coconut-flavored calamari. It is one of two species of octopus which does bipedal motion, using its tentacles like tank treads.
The mugger crocodile Crocodylus palustris in India, during bird migration season, collects sticks on its snout, presenting treacherous rafts to tired birds. The same researcher observed a Yacare caiman which had a water hyancith on its back for at least a week, resembling a mud raft.3
How much intentionality do we attribute to these behaviors? An octopus has to pick up objects of a certain shape and size and hold them a particular way. A crocodile balances sticks on its nose. A snapping turtle acquires clumps of mud and grass on its shell. Some adaptations require less cognition and more stickiness to environmental objects.
Decorator crabs Majoidea adorn themselves with sponges and corals.
Caddis fly larvae Trichoptera build cocoons using materials like sand, pebbles, and twigs.
Locating materials and binding them takes a bit of focus and dexterity. Another approach is to pick up bits and pieces by bumping into them.
Green lacewings Chrysopidae accumulate debris like sand and twigs on their backs.
Peppered moths Biston betularia grow lichen on their wings.
The list gets larger when you count animals having bodies which resemble other lifeforms.
The masked crab spider Thomisus labefactus changes color and shape to look like parts of a flower, and then ambushes pollinators. This might rank higher on intelligence than a stick bug, which to its credit wobbles like a twig in the wind when it walks.
There are different levels of genius baked into the morphology vs. the behavior. Some camouflage strategies require more brain power, some are a function of stickiness, and others are innate appearances.
The best disguises are the ones you grow yourself, but at that point it’s not really constructed camouflage. Still worth mentioning, and possibly the most uncanny camo, the rove beetle Austrospirachtha carrijoi in Australia’s Northern Territory grows an entire fake termite on its back.4 They are full-time imposters for the sake of stealing food. You could have a whole movie about a termite that blows the cover on invading beetles. But termites are blind and rely on touch; so the getaway is not all that difficult.
One idea to test the intelligence behind these disguises would be to remove or negate them and see if the animal’s behavior changes. How strong is its sense of being camouflaged? A naked coconut octopus might seek shelter and new materials, avoiding the open sea floor until it has a new cloak. Does a turtle change its hunting pattern when grass and mud is cleaned off its shell?
Of all these animal spymasters, who is most deliberate and self aware? Who should be the CIA’s Chief of Disguise?
Assassin bug adheres up to 20 ants. https://www.smithsonianmag.com/science-nature/this-insect-uses-its-victims-carcasses-as-camouflage-83656246/
Spider attacks assassin 10x less often when cloaked in dead ants https://zslpublications.onlinelibrary.wiley.com/doi/abs/10.1111/j.1469-7998.2007.00335.x
Beetle grows fake termite to steal food https://www.mapress.com/zt/article/view/zootaxa.5336.3.8