How people use animals: hunting, fishing and domestication
For most of history people got food by hunting and fishing. Today fishing is still a big source of protein. The danger is over-harvesting: taking more animals than are born each year.
About 10,000–15,000 years ago people began domestication: taming wild animals and keeping them for food, work or company. The dog came from the wolf, the cow from the wild aurochs, the chicken from the red jungle fowl, the sheep from the wild mouflon.
Breeds
A breed is a group of domestic animals of one species with similar looks and abilities, made by artificial selection: people chose parents with useful features (more milk, more wool, more strength) and repeated this for many generations. Gir and Sahiwal cows give a lot of milk; Holstein cows are famous worldwide for milk; heavy horse breeds pull ploughs. All dog breeds are still one species.
Pests and urban animals
A pest is an animal that harms our crops, food stores, health or homes: locusts, aphids, rats, termites, mosquitoes. Pests can be controlled with chemicals, but these also harm useful animals, so farmers increasingly use biological control (natural enemies, like ladybirds eating aphids) and crop rotation.
Urban animals are wild animals that have learned to live in towns: pigeons, crows, sparrows, squirrels, monkeys, foxes and stray dogs. They find food in our waste and nest on buildings. Some are welcome, some spread disease. Keeping cities clean and not feeding wild animals reduces conflict.
Why animals are in danger and the Red Book
The main threats are: habitat loss (forests cleared, wetlands drained), over-hunting and overfishing, pollution (plastics, pesticides), invasive species brought from elsewhere, and climate change.
A Red Book (Red Data Book) is an official list of rare and threatened species. The worldwide version is the IUCN Red List. It puts each species in a category: Least Concern → Near Threatened → Vulnerable → Endangered → Critically Endangered → Extinct in the Wild → Extinct. Many countries also keep their own national Red Book. Being listed brings legal protection: hunting, trading and harming the species become illegal.
Protected areas on land
A protected area is land or water set aside mainly to protect nature. Types include:
- National parks: large areas where wildlife and landscapes are strictly protected; visitors may come but not hunt or cut trees.
- Wildlife sanctuaries / reserves: mainly protect particular animals; some human use may be allowed.
- Biosphere reserves: a strict core zone, a buffer zone and an outer zone where people live and work.
- Natural monuments: special single sites such as a waterfall, cave or ancient tree.
Protection inside the area (in situ) is the best way. Zoos, seed banks and breeding centres (ex situ) are a back-up for species that are almost gone.
Protecting the ocean
The ocean faces overfishing, plastic and oil pollution, nutrient run-off from farms, and warming water that bleaches coral reefs. Ways to protect it:
- Marine protected areas (MPAs) and no-take zones where fishing is not allowed. Fish grow bigger and more numerous inside and spill over into nearby waters.
- Fishing rules: catch limits (quotas), minimum net mesh size so young fish escape, closed seasons during breeding.
- Pollution laws: bans on dumping waste, rules for ships carrying oil, and cutting single-use plastic.
- International agreements, because fish and pollution cross every boundary at sea.
Each of us can help: choose sustainably caught fish, refuse single-use plastic, and join beach clean-ups.
Try it: be the fisheries manager
Open the last step of the 3D. The lake starts with 30 fish and can hold 40. Predict first: what is the biggest catch per year that keeps fish alive for 10 years? Try catches of 3, 5, 7 and 9, with and without the reserve. Write down each result. You will find that a catch up to about 5 a year is safe, and the reserve lets you survive a bigger catch.
Key formulas and definitions
- Population next year = this year + births − deaths − catch
- Sustainable: catch ≤ new fish added each year
- Domestication: wild species → tamed by people
- Breed: a variety of one domestic species made by artificial selection
- In situ = protect in the natural home; ex situ = protect outside it (zoo, seed bank)
- Red List order: LC → NT → VU → EN → CR → EW → EX
Worked examples
1. A pond has 200 fish. Each year 50 new fish are added by breeding (after natural deaths). A villager catches 70 fish a year. How many fish are left after 3 years, if breeding stays the same?
Each year the change is 50 − 70 = −20. After 3 years: 200 − 60 = 140 fish. The population is falling, so the catch is not sustainable.
2. Using the same pond, what is the largest catch per year that keeps the number at 200?
The catch must equal the new fish added: 50 fish per year.
3. Is a Labrador and a street dog the same species? Explain.
Yes. Both are Canis familiaris. They are different breeds (or a breed and a mix), made by people choosing parents, but they can breed together and have fertile puppies.
4. A country bans fishing in 20% of its coastal sea. Fishermen complain. Give one reason it may help them in the long run.
Fish inside the no-take zone grow larger and lay many more eggs. Young fish and adults spill over into nearby waters, so catches outside often rise after a few years.
Common mistakes
- Thinking 'endangered' and 'extinct' mean the same. Endangered species still exist and can be saved; extinct ones are gone for ever.
- Saying each dog breed is a different species. Breeds are varieties within one species.
- Believing the sea is too big to be overfished. Many fish stocks have collapsed because catches were larger than breeding could replace.
- Thinking a zoo alone can save a species. Ex situ care is a back-up; the species needs a protected natural home to survive long term.