Recycling's Unsung Heroes:
Scavengers & Decomposers
||Writing, graphic story, drawing, movement
||Social Studies, Science, Art, Language Arts
|You will need
||Thesaurus, dictionary, writing and art materials
||One to two hours
This activity asks students to think in new ecological ways about death and decomposition.
They will do this by looking at social attitudes toward the concepts of death and decay and by making art in any of several ways.
This activity requires students to discuss death of the body. The activity has nothing to do with spirit or soul.
As preparation, teachers are urged to first explore Transformation here.
Life on Earth is a long journey though a series of transformations, or life-stages. All lives transform. The final transformation is bodily death.
Discuss: Nature has been naturally recycling for as long as there has been life on the planet.
To understand how Earth’s ecology works, we will look again at the original methods of recycling.
Recycling is the process of breaking things down so they can again be part of the nutrient pools that all living things build their bodies from.
• What happens after living plants and animals die?
• How do they get recycled?
• Where do their bodies go?
Living bodies assemble themselves by eating, drinking and breathing in nutrients.
After death of the body, disassembly is performed by other organisms called decomposers.
• Without the Decomposers, nothing else could stay alive—including us!
Without these little recyclers of bodies, there would be no available nutrients for new lives to build their bodies from.
• Without decomposers, we would be chin-deep in dead plants and animals in no time.
Life requires Death. Death requires Life.
• Decomposers are organisms which make a living by eating organisms which have died--what kept them alive is gone.
• Really, what decomposers are doing is Transforming the bodies of both animals and plants back into the basic nutrients they were made of.
Decomposers, or Disassemblers, are mostly Bacteria and Fungi.
Decomposers have helpers:
Scavengers and Insects are the big helpers.
Detritus Feeders are the small helpers
• Most life is small; animals are large. Scavengers’ role in the ecosystem is to prepare bodies for further decomposition.Scavengers open up animal bodies so others can share the food--this helps the Disassembling Teams of Fungi & Bacteria to do their jobs.
• Most living matter on land is plant-based. Termites, beetles and carpenter ants eat their way into trees. Some beetles have little pits on their wing cases that contain fungi spores, so as soon as the beetle tunnels into the tree, the fungi can begin decomposition. This relationship is called symbiosis or Interliving.
• Detritus feeders are smaller soil dwelling organisms such as worms and insects (springtails), that live primarily by eating dead plant material.
• Most life on Earth lives in the ocean. There, detritus feeders are enormously important, because everything that dies eventually rains down to the seafloor, or benthos. In the seafloor mud, vast numbers of deep sea worms and smaller organisms prepare dead matter for final disassembly by bacteria.
Like the Decomposers, Scavengers and Detritus Feeders suffer from social stigma; humans tend to regard them with contempt and fear. Many people even look down on garbage-collectors, but they are the first to yell when their trash is not collected.
Some of the more visible scavengers are vultures, crows, jackals, rats, opossums, ravens, catfish, beetles, maggots—all the creatures who use carrion (dead animals) as an important part of their diet.
• How are people eating hamburgers different from scavengers?
• Beef steaks are tenderized by hanging them in coolers for several days, where they just begin bacterial decay. This slight decomposition makes them tender. So the most expensive meat of all is a little rotten.
• Is the steak house restaurant really a scavenger house?
Discuss: Why do vultures have bald heads and necks?
The Decomposers, Detritus Feeders, and Scavengers have bad reputations.
You know, “It’s a dirty job, but somebody has to do it.” Be thankful.The fact is, most of us would rather avoid thinking and talking about the natural processes called excretion, decay and death.
Discuss: How long do you suppose human beings have given the decomposers their bad reputation? Has it always been that way? After all, decomposition is a natural, and fundamental, life-giving process.
Explore Attitudes: In small groups or pairs, use a thesaurus to look up words such as death, decay, rot, corruption, spoil, decompose, carrion, corpse, and so forth, and list some of their synonyms.
•List some of the expressions people use to avoid using the loaded words above.
Also list some of the language we tend to use instead of saying the word dying or death, which show how we avoid thinking about it. Example: passing away, departing, shuffling off this mortal coil, crossing over. These avoidance expressions are called euphemisms.
People find the stink of rotting meat disgusting, and regard scavenging animals such as vultures with some disgust.
Why do you think that is?
• Could it have something to do with the fact that we are meat? That we can imagine vultures eating us?
• Or does it simply remind us that we must die?
Add some verses to the old children's song:
“The worms crawl in,
the worms crawl out,
the worms play pinochle on your snout.”
Make up a poem about the Decomposers and/or Scavengers.
In small groups or pairs, imagine a storyline for a graphic book, or a music video, in which the Heroes are scavengers or decomposers; then draw it or write it as a group. Make a storyboard. Make a short video.
In everyday life, The Scavengers are a truly gross rock band, but underneath their grungy or gothic concert clothing they are Superheroes!
• Write a review of one of their concerts, describing each member of the group. Maybe they are all animals like vultures and jackals or hyenas. Or are they Superhero Bacteria, or Superhero Fungus?
• In a story, show the Scavengers helping us.
• Draw/ Paint the band transforming into Super heroes.
Write or draw a description of your town or city without decomposers. (Dead plants and animals would never change and disappear. Our garbage would never rot.)
• Consider a series of news stories or blog pages: 1 week after stuff stopped decomposing, 1 month after, and so on.
Student Source Sheet Unsung Heroes
A decomposer is an organism, often a bacterium or fungus, that feeds on and breaks down dead plant or animal matter, thus making organic nutrients available to the ecosystem.
Scavenger means an animal—bird, mammal, insect, reptile, fish—which uses dead animals as a large part of its diet. The word scavenger has a negative feeling to it, which is odd, because many humans use dead animals as a large part of their diets. A scavenger’s job is to prepare bodies for decomposition.
The word scavenger comes from an old Middle English word scauager, schavager: an official charged with street maintenance. Think road kill. Crows do a lot of “street maintenance.”
Some very visible scavengers are Crow, Raven, Vultures, and fly larvae called maggots. In aquariums, the bottom-feeding catfish are scavengers. Many animals who hunt their food, such as jackals, also scavenge at times. Most scavengers we don’t notice much. They are insects and mites, most of them tiny. Dust mites live on dead human skin cells which we shed by the thousands every day. Hey, it’s a living!
Creatures which feed on dead vegetation are also scavengers,
called detritus feeders, although most humans don’t find them disgusting. Earthworms are hugely important scavengers; they create topsoil all over earth. Bottom-dwelling ocean worms are just as important as they help recycle the multitude of dead organisms which continually sift down to the ocean floor.
Some dinosaurs must have been scavengers. Giganotosaurus, a therapod dinosaur of the middle Cretaceous Period, about 100 million years ago, is the largest carnivorous dinosaur yet found. Its fossil remnants were first uncovered in the Patagonian region of Argentina in the late 1980s. Because of its size, Giganotosaurus could as likely have been a scavenger as a pursuer of live prey. Giganotosaurus was a contemporary of the vegetarian Argentinosaurus, perhaps the largest land animal that ever lived.
Scavenging must be a good way of making a living (get energy). Among the Scavengers are some of the most intelligent creatures around. The Crows and Ravens and Magpies are really smart. So is the jackal.
If you give life, you must necessarily give death, because life always ends in death, and must be renewed through death.
— James Lovelock, The Ages of Gaia
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