Pigs are very intelligent animals: the fourth smartest on the planet. They form close friendships and communicate by making different sounds such as squealing or grunting. Mother pigs sing to their piglets. A pig’s snout (nose) is an important tool for finding food and sensing the world around them, they have an excellent sense of smell. In the wild, as they move the soil around, this encourages new plant growth and spreads seeds. Over 90% of farmed pigs live in cramped, solitary conditions.
The Arctic tern is a small seabird which travels further than any other bird in one year, around 40-90,000 km. It breeds in the Arctic before making its way south to the Antarctic. They follow a zigzag route; probably following huge, spiralling wind patterns to avoid flying into the wind. This is a remarkable journey for a bird that only weighs around 95-120g, with a wingspan of 75-85cm. Some colonies have been affected by fish shortages due to over-fishing.
Wild turkeys primarily live in woodland in North America where their dark feathers are good camouflage. The males fan out their tail feathers like a peacock; the bare skin on their neck changes colour: red for fighting, blue for excitement. The young stay with their mother for a year and develop unique voices. They are highly social and can memorise large areas of terrain. Most domestic turkeys are bred to be so heavy that they are unable to fly.
Earthworms loosen and mix up the soil, break down and recycle decaying plant matter and bring nutrients closer to the surface, where they can be used by plants. Birds often rely upon worms as a source of food. Earthworms range in length from a tiny one millimetre to a massive three metres. Charles Darwin studied them for around 40 years. Industrial farming harms earthworm populations where fewer than 30 earthworms can be found per square meter; elsewhere it can be up to 450.
There are many species of tuna including the bluefin which is a top predator and may hunt in a ‘pack’ like wolves. Not only do they have a streamlined body with retractable fins but, unlike other fish, it can regulate its body temperature; these features enable them to swim fast (over 40 mph) and strong across the oceans as they migrate. They can grow up to 3m long and weigh around the same as a horse. Although tuna are listed as endangered species, fishermen around the world hunt them persistently.
These social animals, considered to be as smart as some primates, live in clans of up to 80, in varied environments across sub-Saharan Africa. These strong, skilful animals usually hunt their own prey, often at night (nocturnal); they don’t just scavenge for food. Their jaws are so powerful that they can even eat bones. Due to habitat loss, the spotted hyena population is declining but the striped and brown hyenas are ‘Near Threatened’. Hyenas are hunted, trapped and poisoned by humans.
There are nearly 250,000 species of moth compared to only about 20,000 species of butterfly. They are important because they pollinate plants that flower in the evening and during the night. It appears that moths often get overlooked because they aren’t very colourful but many are beautiful, like the Madagascan moon (or comet) moth pictured. This moth is related to the farmed silkworm. One continuous white or yellow strand of silk, about 915 metres long, forms part of their cocoon within which they pupate (change from a caterpillar to a moth). This strand of silk is preserved intact for commercial use by killing the pupa with hot air or steam.
Orangutan means ‘person of the forest’ in Malay. They mainly eat fruit (over 300 types) and are thus also known as the gardeners of the forest because they distribute seed. Their tool use is very developed, some even use leaves to make their calls louder. They spend most of their time in trees (arboreal) and the arm span of a male can be up to two metres. Orangutans usually live alone, except the young and their mothers, who remain together for the first 10-12 years. Orangutans are critically endangered; their habitat is being destroyed (often for oil palm plantations) and they are hunted by humans.
Reptiles are ectotherms (cold-blooded) which means they cannot generate their own body heat like humans and other mammals. They can often be found ‘sun bathing’ on rocks or in a woodland clearing in their native Australia. When they get too hot they open their mouths to cool off. They can move very quickly and are great climbers. The colour of their skin normally matches the soil that occurs in the dragon’s habitat. When startled they puff up, the ‘beard’ then appears scary to a predator. It is becoming popular to keep these free-ranging animals as pets in a restricted area.
Antarctica’s cold and windy climate means that there is very low biodiversity (few species). The only resident land animals are invertebrates (without a backbone). The lowest temperature recorded in Antarctica was -89.2°C (-128.6°F) in 1983. To avoid being frozen solid, they produce antifreeze. The 1mm mites (eight-legged creatures related to spiders) are the top predators in Antarctica preying on other microscopic creatures. Unfortunately, this part of the world is already under threat from climate change.