http://www.bbc.co.uk/nature/adaptations

Adaptations help organisms survive in their ecological niche or habitat; adaptations can be anatomical, behavioural or physiological.

Anatomical adaptations are physical features such as an animals shape. Behavioural adaptations can be inherited or learnt and include tool use, language and swarming behaviour. Physiological adaptations include the ability to make venom; but also more general functions such as temperature regulation.

Adapted to extremes

Adaptation to extremes encompasses all the special behaviours and physiologies that living things need to withstand the planet’s harshest conditions and environments. Whether it’s a lack of oxygen at altitude, the searing heat of deserts or the bitter cold of the polar regions, plants, animals and other organisms have evolved a multitude of coping strategies

Altitude tolerant

Altitude tolerant organisms are adapted to living high up where oxygen levels – or carbon dioxide levels in the case of plants – are low. The upper reaches of mountain ranges are also often bitterly cold, or subject to swinging daily extremes in temperatures.

Chemical tolerant

Chemical tolerant describes organisms which can tolerate high concentrations of substances which would be toxic or corrosive to other life. For instance plants that can live in the acidic and low oxygen conditions of peat bogs, flamingos that can tolerate the alkaline waters of soda lakes and brine flies which can live and breed on salt flats.

Cold tolerant

Cold tolerant organisms have evolved various methods for coping with very low temperatures. Some animals hibernate, take shelter, or even migrate to warmer areas. Others, such as Antarctic seals, have warm fur and a thick layer of blubber for insulation. Arctic plants tend to be small and grow low to the ground and can be coated with hair and wax to avoid wind chill. Some insects, amphibians and microbes can even withstand being frozen solid.

Dry tolerant

Dry tolerant plants and animals are able to cope with conditions where water is hard to find. Strategies include preventing its loss, storing for later use and being able to survive on less than normal. These adaptations aren’t only important for organisms that live in tropical hot deserts. They’re also necessary for those that inhabit the cold deserts of the polar regions, and non-desert areas that suffer from periodic or seasonal droughts. Cacti are among the most drought resistant plants on the planet and are able to store water in their stems and roots. Some can even survive years of drought after a single rainfall.

Fire tolerant

Fire adapted organisms benefit in some way from the occurrence of bush or forest fires. Birds of prey might catch insects fleeing from the flames and Temminck’s coursers lay their eggs on scorched ground to take advantage of the open space and to feed on the insects that perished in the fire. Certain plants have gone one step further and become totally dependent on heat and flames to open their seed capsules or trigger germination.

Heat tolerant

Heat tolerant animals and plants have special adaptations for survival in hot places. Many animals try to avoid the heat by hiding away during the hottest parts of the day in burrows and dens. Others have physical adaptations that help body heat dissipate, such as large ears. To avoid being scorched, plants may turn their leaves away from the sun’s glare. Small waxy leaves and the ability to close pores help other plants to reduce water loss.

Animal intelligence

Animal intelligence covers behaviour that’s considered above the norm for an animal. Some species may be unusally adept at learning new skills or using tools. Others have highly developed social and even emotional skills and may even have developed a distinct culture, in a similar way to human beings.

Culture

Culture is a social system or set of behaviours that is passed down through the generations, and which differs from that seen in other populations of the same species. So for instance, all killer whales are carnivorous, so that is not cultural. But only certain pods of killer whales beach themselves to catch seals, and the necessary skills are taught to young whales by their mother, so that is cultural. Distinct cultures have been observed in many primates and some birds as well as in whales and dolphins.

Language

Language is a way of communicating through sound, where specific meanings are used in certain circumstances. Many animals have a generic alarm call used for all dangers – this is not language. However, vervet monkeys have different calls for warning each other about snakes, eagles and leopards, and this is sophisticated enough to be considered a proto-language. Other animals with these ‘proto-language’ abilities are dolphins, apes and parrots.

Learning

Learning is the process of picking up new skills. An animal may learn from its own experiences or be taught by another animal, often a parent. Most animal learning is done by observation, followed by trial and error. Play is an important way of learning for many species particularly for honing physical skills such as hunting. Human beings have language, so can speed the whole process up by explaining what the learner is doing wrong and how to correct it.

Tool use

Tool use was once thought to be a strictly human behaviour, but it is now known that many kinds of animals use tools. These include crows, dolphins and – of course – primates such as chimpanzees. Some animals, sea otters for one, have a favourite tool that they carry about with them. Others find nearby articles such as stones, twigs or thorns, which they use and then discard. Advanced use comes about when tools are used in combination, as when chimps use both a hammer and an anvil to crack kernels.

Behavioural pattern

Behavioural pattern describes an animal’s dominant way of life. Arboreal animals, for example, live in trees and nocturnal animals are active at night.

Air plant

Air plants, or epiphytes, complete part or all of their life cycle anchored or perched on another plant or structure rather than rooted in the soil. They obtain water and nutrients from dew, air moisture, rainwater and collected plant debris via adventitious (growing from the stem or leaf) and aerial roots. Epiphytes include many lichens and mosses, as well as 10% of all seed plants and ferns and over half the orchid species. This way of life isn’t parasitic, in contrast to plants like mistletoe, which ‘steals’ nutrients from the host tree.

Burrower

Burrowing, or fossorial, animals live underground and for a variety of reasons. For some it is so they can feed on soil flora and fauna, for others it’s to avoid predators or to hide away from the extremes of climate above ground. So, a British mole avoids the worst of the winter cold in its tunnels, whilst a naked mole rat in Africa gets protection from the heat. Both have some protection from roaming predators.

Cave dweller

Cave dwelling, or troglophilic, animals spend their whole lives in cave systems. Living in perpetual darkness, many cave species have lost the sight that their evolutionary ancestors had and become blind. Vestigial eyes can often be seen. They’re also usually pale in colour as they don’t need to produce skin pigment as camouflage or protection from the sun.

Nocturnal

Nocturnal animals are primarily active at night rather than during daylight hours. There are all sorts of reasons why this behaviour might be a good idea. In hotter places such as the tropics, it’s cooler at night. If you’re a bat, then your ancestors took to the night skies to avoid competition for resources from birds. And, of course, it’s easier to hide from predators under cover of darkness.

Nomadic

Nomadic animals wander from place to place, using no particular fixed routes – unlike a migration – rather than staying in one tightly defined area. There are boundaries to their wanderings and some species, wolves for example, are still territorial. Often, animals may be nomadic only part of the time, during particular seasons, like badgers, or particular life cycle phase, as with young male lions. Nomadism in these cases has reproductive advantages, allowing males to visit different groups of females and ensure a healthy gene pool.

Parasitic

Parasitic organisms have a close relationship with another organism, which they use ultimately to extract food. The process generally harms the host, and may even kill it. Parasites can either live on the surface of the host – like blood sucking fleas – or inside it like tapeworms. There are examples of parasites in both the plant and animal kingdoms and some fairly gruesome fungi.

Sessile

Sessile describes animals that don’t move around, such as barnacles and corals. There may be mobile phases in the life cycle, often in the larval stage, where organisms might actively swim or merely drift about, but they will eventually fix themselves in place and remain there for the rest of their lives. Because sessile animals can’t go off in search of food, this is only a practical lifestyle if you live in water, where the currents or tides will carry food particles to you.

Swarming

Swarming happens when animals gather or travel together in large numbers. Its most familiar examples are in insects, such as locusts and midges, flocking birds and shoaling fish. Some animals swarm as a defence against predation, others, such as locusts and bees, only form swarms in specific circumstances. Swarming can be carried out by the smallest and simplest micro-organisms, such as bacteria, and even by humans.

Symbiotic

Symbiosis is a relationship between two organisms that’s beneficial to one (commensal) or both (true symbiote). For instance, giant clams have algae living within them. They each recycle the other’s waste products and supply their partner with nutrients. Symbiosis can exist between different kinds of organism, such as between plants and fungi or plants and animals, as well as between different species.

Tree dweller

Tree dwelling, or arboreal, animals are particularly well adapted to spending most or all of their time in trees. They range from tiny invertebrates to huge orangutans. At the medium to large end of the size spectrum, special physical adaptations aid locomotion up and through the trees, such as prehensile tails, specially adapted claws and loose joints for easy swinging.

Communication and senses

Communication and senses are how an organism perceives the world – for instance through scent or sight – and how it sends messages or warnings to others.

Acoustic communication

Acoustic communication is the sending and receiving of messages using sound. Bird song, the roars of lions and the chirping of cicadas are all examples of this. Sometimes the messages are outside the range of human hearing, such as the ultrasonic squeaks of baby rats or the infrasound rumbles of elephants. Most acoustic communication is not language, in the sense that humans use it, although language is one aspect of this adaptation.

Bioluminescence

Bioluminescence is light created by living organisms and and it can create the most fantastic displays. It includes ‘phosphorescence’ created by marine creatures and seen on the surface of the sea at night, the light of fireflies and the faint but eerie glow of some fungi. The light is produced chemically for many different reasons: to attract attention, to frighten enemies, to disguise what you really are, or – in the depths of the sea – to provide your own ‘headlights’ to search out prey.

Chemical communication

Chemical communication is all about taste and smell. Plants use scent and pheromones to attract pollinators. Animals use scents and tastes for a whole variety of reasons, including scents emitted by female moths to attract a mate, alarm signals given off by bees when their hive is under threat and the territorial markers in wolf urine. Some insects, such as ants, lay down pheromone trails for their nest-mates to follow to food sources. Many animals have special scent glands for leaving these chemical messages.

Echolocation and ultrasound

Ultrasound is high frequency sound that’s above the range of human hearing. Some animals produce ultrasound for communication or for navigation. Baby rats call to their mothers with high pitched squeaks inaudible to humans. Dolphins use ultrasound to echolocate and find their way around in murky or dark water.

Mimicry

Mimicry is when an animal or plant resembles another creature or inanimate object, either for defence or to gain other advantages. Pebble plants try not to be eaten by resembling stones, praying mantises hope to lure prey close by resembling flowers. The mimicking species may smell, sound or behave like the creature or object it is duplicating, not simply look like it. For example one type of firefly mimics the light flashes and pheremones of another in order to catch and eat it.

Tactile sense

Tactile sense includes the obvious sense of contact with another object, but also incorporates a bird’s ability to sense air flow over its wings and a fish’s sensitivity to water movements. Some creatures, such as the yapok and the star-nosed mole, have a highly sensitive sense of touch through specialised organs that they use in situations where eyes are of no use.

Visual communication

Visual communication transmits information to others through shape, colour and movement or body language. Animals can both send and decode visual messages, using colour and behavioural displays for messages as varied as threat, invitations to mate and identification of what species they are. Though plants can’t themselves see, they use visual cues such as colour to attract animals to their flowers and fruits. Visual perception differs radically among various groups of animals, from the ability to see in low light, to detection of the slightest movement.

Warning colours

Warning colours (aposematism) describes colouration and other markings that send a signal to predators to keep away, often because the owner is poisonous or simply tastes bad. Warning colours are usually two contrasting ones, such as yellow and black, in stripes or blobs for maximum impact to multiple species, since even colour-blind animals can see patterns. As this anti-predation strategy is so useful, some animals cheat. Eye spot patterns make them look like larger organisms or bright colours might warn away even though they are safe to eat. The hoverfly is striped like a wasp, but has no sting.

Ecosystem role

Ecosystem roles are about the part an animal or plant plays in sustaining or maintaining the habitat around them. Bees, for example, pollinate flowers, without which those plants would not produce fruits or seeds. Other species, such as dung beetles, play a vital role in keeping grasslands clear of animal waste and recycling valuable resources.

Detritus recycler

Detritus recyclers are the cleaners of the ecosystem, ridding the area of rotting material and recycling energy back into the food chain. They consume the non-living, organic material such as leaf-litter or fragments of dead and decomposing animals. In aquatic ecosystems, detritus is suspended in the water in tiny particles referred to as marine snow, which is often consumed through filter feeding. Fungi and creatures like woodlice are important land detritus recyclers.

Pollinator

Pollinators carry pollen from plant to plant and, often unwittingly, play a crucial role in plant reproduction. Bees are the most familiar pollinators, but plants attract thousands of different types of animals – using all sorts of alluring strategies: colour, scent, structure – to carry out this ecosystem role. Some of the larger active species include fruit bats, hummingbirds and even lemurs. Without pollinators millions of human beings would starve, as most of our crops depend on them.

Seed dispersal

Seed dispersal is when seeds are carried away from the parent plant either deliberately or accidentally. Often, animals are involved in dispersal, as when ants, squirrels and mice, collect and store seeds (including nuts). If the store is forgotten, or the animal dies, the seeds might germinate. Other animals may eat a plant’s fruit and scatter the undigested seeds in their dung. Finally, some seeds are sticky or have hooks that catch on to fur and feathers, so the seed can hitch-hike to a new location. The seeds of some plants are carried by other vectors such as wind and water.

Feeding habits

Feeding habits describe the dominant diet of a particular species or group of species, and how they go about obtaining it.

Blood sucker

Blood suckers take a variety of forms, many of them parasitic, from small invertebrates to larger mammals. Specialised features, such as the vampire bat’s front teeth or the proboscis of the mosquito, help puncture the skin of their victim and there may also be chemical activity to prevent the victim’s blood from clotting and ceasing to flow. Blood is full of nutrients, which makes it an attractive option for an easy meal.

Carnivorous

Carnivores are animals whose main method of getting food is to kill and eat other animals, or to scavenge their dead flesh. Typically, the word brings to mind the large predators at the top of the food chain – lions, wolves and the like – but insectivores (insect eaters) and piscivores (fish eaters) are equally carnivorous. The group of mammals, Carnivora, are so called because so many of the species in it (felines, canines, etc) are defined by their carnivorous diet. Some plants are also carnivorous.

Dung eater

Dung eaters feed on waste, either of other species or their own. Those that eat their own, such as rabbits and ringtail possums, do it because it’s so hard to extract nourishment from their nutrient-poor diet that digesting it a second time is worthwhile. In contrast, pikas eat their own dung to keep their salt levels in balance. Some dung eaters, like the dung beetles, play an important ecosystem role in recycling waste and helping to disperse or germinate seeds in the dung.

Herbivorous

Herbivores are animals that exist mainly on a diet of plants or algae. Some eat a wide range of plants, others are more exclusive and eat only particular types, such as monarch butterfly caterpillars which feed on milkweed and pandas on bamboo. Anatomical and physiological adaptations help some herbivores become specialists, for example, in their tolerance of spiky leaves or an in-built antidote to toxins. Other specialists restrict themselves to certain parts of a plant: hummingbirds feed on nectar and greenfly feed on sap.

Kleptoparasitic

Kleptoparasitic animals are thieves and bandits. They steal food, nest material or other resources from their own species or from another one. Gulls are a famous example – they harass other seabirds such as puffins and kittiwakes into giving up their fish, and even snatch chips from unwary people on many a seafront. Lions and hyenas both steal each other’s kills, so both can be considered kleptoparasitic.

Scavenger

Scavengers are those carnivorous animals that eat carrion (already dead animals) rather than hunting fresh meat for themselves. Some scavengers, such as African vultures, rely wholly on what they can get this way. Others, such as lions or wolves, are opportunistic scavengers and while they won’t pass up a free meal, prefer to hunt their own prey. It’s a surprise to many that even some herbivorous species, such as hippos and pandas, are known to scavenge carrion now and then.

Life cycle

Life cycle describes all the different stages through which an animal, plant or other organism passes from conception, through adulthood to death. Encompassed here are not only the major physiological stages of growth and development, but also temporary occurrences such as moulting and experiential phases such as courtship and parenthood.

Courtship display

Courtship displays are performed by animals seeking to advertise their willingness to mate, attract a partner and sometimes to warn off rivals. Famous examples include the dazzling display of a peacock’s tail, and the elaborate dancing and acrobatics performed by birds of paradise. In monogamous animals, such as swans and albatrosses, the male and female often do a mutual courtship display, to reaffirm and reinforce the bond between them.

Maternal care

Maternal care is where the mother of the offspring provides most or all of the effort needed to protect, feed or raise the young. In egg-laying species, maternal care includes looking after the eggs before the young hatch – for instance a mother crocodile guarding her clutch. In mammals, only the mother can provide the milk that youngsters are dependent on for the first part of their lives, so in many species all the primary care is done by the female, though males may play a part in defending or providing for the female.

Metamorphosis

Metamorphosis is when a species changes body shape and structure at a particular point in its life cycle, such as when a tadpole turns into a frog. Sometimes, in locusts for example, the juvenile form is quite similar to the adult one. In others, they are radically different, and unrecognisable as the same species. The different forms may even entail a completely new lifestyle or habitat, such as when a ground-bound, leaf-eating caterpillar turns into a long distance flying, nectar-eating butterfly.

Moulting

Moulting is all about renewing your skin, fur or feathers, and occurs in animals for a number of reasons. Some creatures, such as snakes and insects, need to shed their skins in order to grow. Birds moult their feathers at least annually to replace damaged ones, and some species also take the opportunity to change into breeding colours or to turn white in winter for camouflage. Mammals may shed their fur for a thicker winter or thinner summer coat, and again some types may change fur colour with the seasons.

Parental investment

Rearing young occurs where the eggs or offspring require looking after, and cannot just be abandoned to fend for themselves as with many species. Care investment may be made before or after birth and the different roles may be carried out by one or both parents. So, for instance, birds need to incubate their eggs and the mother and father often share this duty. Parenting can last for days, months or years with varying levels of involvement by each parent. Sometimes, cooperative breeding takes place where other members of the family assist the parents in looking after the young.

Paternal care

Paternal care is where the father of the offspring provides most or all of the effort needed to protect, feed or raise the young until they become independent. The most well-known example of paternal care is in seahorses, where the male broods the eggs in a pouch until they are ready to hatch. Primary paternal care is most common in egg-laying species and almost unheard of in mammals.

Locomotion

Locomotion is how an animal gets around – for instance by swimming, flying or climbing.

Adapted to climbing

Scansorial describes animals that spend much of their life climbing such as squirrels, monkeys, geckos, mountain goats and tree frogs. Whether it’s a tree, a cliff or a wall, what an animal climbs has a great influence on how evolution has equipped it for the all important task of not falling off. ‘Suction pads’ on geckos and the hook-like claws of the sloth are some of the many useful features for a climbing life.

Adapted to flying

Flying, in its true sense, is the ability to move through the air under your own power and has evolved in different groups of animals. Flight is a very energy demanding method of locomotion compared to walking. Some species, such as the peregrine falcon, are extraordinarily well adapted to flying. Others, like the albatross, look like they shouldn’t be airborne at all, but are in fact fantastically efficient flyers. In spite of their name, flying squirrels and flying lizards don’t fly, but glide.

Did you know?
Birds, bats and pterosaurs all evolved flight separately, a classic example of convergent evolution.

Adapted to gliding

Gliding is where after an initial leap, animals rely on gravity to get them where they are going. Gliding animals can steer, but they can’t ascend on their flight path and don’t propel themselves through the air under power. Animals as diverse as fish, squid, marsupials and snakes have all learned to glide, and may have evolved features to help to keep them airborne for longer, such as skin flaps on limbs. Flying snakes glide through muscular contraction. Some plants have winged seeds which are designed to glide as a means of dispersal.

Adapted to jumping

Jumping is a method some animals have evolved to get around efficiently. Gerbils, kangaroos, frogs andgrasshoppers have all evolved long pairs of legs with large muscles positioned at the back of their body for maximum hopping power. Other mechanisms include the spring-like ‘tail’ of the aptly named springtail, which is coiled under tension so that when it’s released the animal is propelled upwards.

Did you know?
A springtail’s leap is equivalent to a human jumping over the Eiffel Tower.

Adapted to running

Running and walking evolved as a method of getting around when life emerged from water on to dry land. Animals that travel about on foot usually have a particular speed of gait which is their most energy efficient. Fast running mammals, such as zebras and cheetahs, have evolved features such as long legs and a flexible spine to boost their speed.

Adapted to swimming

Adaptations for swimming enables animals to move around in water. Animals that can swim proficiently (natatorial) fall into three categories. Those that evolved in water (for instance sharks and jellyfish), those that had land living ancestors but have returned to an aquatic life (dolphins and manatees) and those that split their time between water and land (penguins, crocodiles) and need to move around efficiently in both mediums. Animals that simply go for a swim now and then – say to cross a river – are not specifically adapted to swimming, though this behaviour may be of interest.

Morphology

Morphology is anything to do with what a plant or animal looks like – its size, shape, colour or structure.

Camouflage

Camouflage is the art of not being seen, practised by predators, prey and plants. Colour might help an organism blend in with their environment – even when the organism itself cannot see in colour. Body shapes can make them appear to be some other object common in the same surroundings. Patterns might sometimes make an animal more noticeable, but they can also help disguise outline. The tiger’s stripes and the giraffe’s patches make them almost impossible to detect in dappled light.

Neoteny

Neoteny refers to animals that retains juvenile features even when they become adults. The most well-known example is the axolotl, a type of salamander that remains tadpole-like all its life, never losing its gills and never leaving the water to live on land. Neoteny is an important feature in evolution: human beings are neotenous primates and insects might be descended from a neotenous millipede-like ancestor.

Polymorphism

Polymorphism means ‘many forms’ and can be exhibited in a variety of ways. A truly polymorphic species has individuals of notably different appearance living in the same area. Army ants, which have workers of different sizes in the same nest, are therefore polymorphic as are adders which can have a zig-zag pattern on their skin or be uniform black in colour. If the difference is between males and females of a species, as with peacocks and peahens, it’s sexual dimorphism rather than polymorphism.

Sexual dimorphism

Sexual dimorphism describes animals where there is a physical differences between males and females of the same species (other than in the sex organs). One may be significantly larger than the other, colouration may be different or one might have additional body parts such as antlers, ornate plumage or a mane. In the rarer cases where females are larger or more ornate it is termed reverse sexual dimorphism.

Predation strategy

Predation is catching and killing an animal in order to eat it and different species have evolved a range of strategies for doing this efficiently. The most frequently used methods are variations on chasing and capturing if the predator is a fast runner, ambushing to conserve energy, or using a trapping mechanism such as a spider’s web.

Ambush predator

Ambushing prey is a tactic employed by a whole host of animals, from trapdoor spiders lurking in their burrows, to a cat stalking a mouse. If ambushers chase their prey at all, they do so for only a short time, as most of them are not capable of a prolonged pursuit. Instead they use cover so they can surprise unsuspecting prey.

Pack-hunter

Pack-hunting is a type of predation where several members of a species combine their efforts to increase their chance of success in the hunt. Well known pack-hunters are lions, wolves and army ants. Some pack hunters have tactics based on sophisticated teamwork, with each animal playing a specific role. Other pack-huntes are less organised, relying on weight of numbers to overwhelm prey rather than on a planned strategy.

Predator

Predators are creatures that catch and kill other animals for food. All sorts of techniques are employed by different animals to maximise their chance of catching prey, and to balance the energy expended in catching prey with the energy gained in eating it. Some execute long chases, outrunning their prey, others ambush or hunt in groups. Some construct elaborate traps and many have mechanisms for stunning or poisoning their victims.

Trapping predator

Trapping predators perform a particular type of ambush that involves constructing something to help them catch their prey before they pounce on it. For example, spiders construct webs and fungus gnats dangle a lure of sticky silk to ensnare other organisms.

Venomous

Venomous organisms inflict poisonous wounds by actively biting, stinging or scratching their victims and injecting toxins into them. This distinguishes them from poisonous species which usually contain or secrete toxins and need to touched or eaten to contaminate their victims. Envenomation can be a predatory tactic or a defence mechanism. It can be costly to produce and to inject toxins, so often organisms will use as little venom as possible in an attack.

Reproductive strategy

Reproduction covers all the tactics and behaviours involved in obtaining a mate, conceiving the next generation and successfully raising them. It includes everything from plants being pollinated, to stags fighting over hinds, to lionesses babysitting their sisters’ cubs.

Active at birth

Active at birth, or precocial, describes species that are physically mobile and able from the moment of birth or hatching. Wildebeest calves, and many other grazing animals, need to be up and running from the word go, to avoid becoming dinner for nearby predators. Newborn dolphins have to be able to swim immediately. Precocial birds, like ducks and chickens, can often feed themselves as soon as mum shows them what is edible. Offspring that are helpless at birth – humans and mice, for example – are the opposite, altricial.

Asexual reproduction

Asexual reproduction is the production of offspring by only one parent. No fertilization of an egg cell or mixing up of the genes takes place, so all the offspring are genetically identical copies of the parent. Greenfly, hydras and strawberry plants can all reproduce asexually as well as sexually.

Co-operative breeding

Co-operative breeding is when parents recruit the previous year’s grown up offspring or other adult helpers to help raise the latest brood or litter. The minders may look after the young in creches, or individually. Examples include bee-eaters, wolves and of course, humans. If grandma or a child minder helps look after the kids, then that’s co-operative breeding!

Egg layer

Oviparous animals lay eggs, inside which the young then develop before hatching occurs. Birds, reptiles, amphibians, fish, invertebrates and even some mammals (the monotremes) all lay eggs but they’re of very different size and construction. The patterns on bird eggs are produced by glands right at the last moment as the egg is laid. For terrestrial species that lay their eggs on land, a waterproof shell prevents the contents from drying out.

Flowering

Flowering is definitely the most successful plant reproductive strategy and has opened up nearly every habitat on Earth for colonisation. Usually brought on by a change in temperature or daylight, flowering is the reproductive stage of a plant’s life cycle. Flowers are designed to encourage the transfer of male pollen to female ovule, and the subsequent production of seed-bearing fruit. A remarkable variety of methods is used to attract insects, birds and even bats: from nutritious nectar to bright colours and scents – not all of which are pleasant. Less showy flowers are serviced by the wind.

Helpless young

Helpless, or altricial, young describes babies that are not very well developed and are utterly incapable of taking care of themselves. Humans, rats and blue tits are prime examples. The young are often hair, or furless, can’t yet walk or fly, and are often blind. They rely entirely on their parents for warmth, transport and food. Usually, altricial babies are a feature of big litters, though humans are an obvious exception here. The opposite of altricial is precocial . active, mobile offspring.

Hermaphroditic

Hermaphrodites have both male and female sex organs, either throughout their lives (homgamy) or that develop and mature at different points in their life cycle (dichogamy). Most dichogamous species, including many flowers and fish, change sex only once in their development. These organism still need another individual at the opposite stage for fertilisation. Homgamous species may be capable of self-fertilisation, but generally two individuals exchange sex cells and both are fertilised.

Monogamous

Monogamous animals partner up with a single mate, sometimes for the duration of a breeding season and less commonly over multiple seasons and years. Monogamy has particular advantages, and is often the chosen strategy where young are more vulnerable and require both parents for protection and feeding. In serial monogamy, having different partners each season helps maintain genetic diversity.

Ovoviviparous

Ovoviviparous animals produce eggs inside their body, but then give birth to live young. The eggs hatch out inside the mother and the offspring stay within her for a time. She later gives birth to the them. While they are within her, the young are fed on the yolk of the egg, and not directly from the mother’s body. Ovoviviparity is a special type of viviparity. Some fish, amphibians and reptiles reproduce this way, for instance the sand tiger shark.

Parthenogenetic

Parthenogenetic species – for example water fleas – reproduce asexually, without need of a male, mating or pollination. In parthenogentic animals, the offspring are usually all female, and in certain types of whiptail lizards, the entire species is female. Parthenogenesis often happens where there are no males of a species in the vicinity. In some cases, should males make a reappearance, the species can switch back to sexual reproduction. Recently in zoos, komodo dragons were discovered to be capable of this reproductive trick.

Polygynandrous

Polygynandrous describes a multi-male, multi-female polygamous mating system, such as that seen in lions and bonobos. Females are usually more numerous than the males and mating occurs only within the group. The advantage of this form of polygamy is greater genetic diversity, less need for males to compete with each other and greater protection for the young.

Polygynous

Polygynous sexual behaviour is the system in which a single male mates with multiple females, but each female mates with only one male. This usually entails fierce competition between the males during the breeding season. Females invest more heavily in their offspring and all the parental duties fall to the mother. They become much more choosy about their mate as a result, while the males attempt to have as many mates as possible in order to leave a maximum number of offspring. However many males fail to win or impress a female and remain unmated their entire lives.

Semelparous

Semelparous organisms reproduce only once in their lives and then die. The most well known ones are Pacific salmon that perish after spawning. Other examples are squid, mayflies and plants which die after setting seed (annuals). The adult diverts resources into producing huge amounts of offspring to ensure sufficient numbers reach maturity without any parental care. This is why bears largely ignore dead salmon after they’ve spawned – all the salmon’s fat has gone into producing sperm and eggs and little nutrional value is left.

Spawning

Spawning animals deposit a mass of eggs and sperm in water, where they meet and are fertilised. Even when the male and female animals are in close proximity, such as a male frog grasping the female, the eggs are fertilised outside the female’s body. Some animals, such as coral and many fish, synchronise their spawning so that millions of eggs are released at once in often quite impressive events.

Viviparous

Viviparous animals bear live young that have developed inside the mother’s body. Most familiar to us in mammals, there are a few unexpected ocurrences in animal groups usually associated with egg-laying such as reptiles, amphibians, fish and scorpions. The term can also be applied to some plants, such as certain kinds of succulents and waterlilies, where the seeds germinate while still attached to the parent.

Social behaviour

Social behaviour is all about how an animal interacts with members of its own species. For instance, does it live in a colony or on its own, does it fight to be top of the pecking order, or does it try to keep strangers away from its home?

Colonial

Colonial animals live in large groups in close proximity to one other. Colonies might exist only at specific times of the year such as the nesting season for many seabirds. Others, such as a beehive or a den of meerkats, contain a single social unit,and often last for longer than the lifetime of an individual member.

Eusocial

Eusocial describes species with a very highly developed social structure. Ants and termites are all eusocial, as are some species of bee and wasp and a few very unusual mammals. Eusocial animals live in colonies in a strict caste system. The queen and her consort are the only members of the colony that breed and the majority of offspring become workers and soldiers who gather food, protect the colony and raise the young on the queen’s behalf.

Hierarchical

Hierarchical animals have what is known colloquially as a ‘pecking order’. Animals at the top of the hierarchy aggressively dominate those lower down the ranks in order to retain privileged access to resources such as food, mates or a safe places to sleep. Males are often likely to dominate a pack, but there are some exceptions, as in spotted hyenas where females outrank males. In other cases there may be an alpha female in addition to an alpha male, as in wolves where she is the only one that will bear pups.

Social

Social animals like hanging out with members of their own species. But to be truly social, the group of animals isn’t just a random collection of individuals. Instead the members recognise each other (by scent or sight) and co-operate with each other in some way – for instance getting together to defend a communal territory.

Territorial

Territorial animals actively defend the area in which they live and more importantly on which they depend for resources. If the animal doesn’t advertise its ownership and defend it from members of its own species, it isn’t territorial. Often, advertising takes the form of scent marking the territory boundaries as a clear marker for others to stay away. Challenges and disputes can be resolved in a number of ways, not always violently. In addition to these ‘traditional’ territories, the males of some non-territorial species – such as wildebeest – establish temporary mini-territories in the mating season to impress the females.

Survival strategy

Survival strategies enable organisms to cope with particular stresses, from temporary environmental changes in the weather to the constant threat of predation. So, for instance, to avoid the cold of winter animals may migrate away or hibernate, while trees may shed their leaves. To avoid predation, plants may be poisonous or covered with defensive spikes and animals may use camouflage or travel in great numbers.

Aestivation

Aestivation is a period of deep and prolonged sleep, or torpor, that occurs in the summer or dry season in response to heat and drought. Food can often be scarce at such times, so animals avoid using up hard won energy reserves by lowering their metabolic rate. This reduces the need for food and water during hard times, ensuring longer-term survival.

Food storage

Food storage is a strategy for getting through hard times when resources are low because of seasonal or other factors. Some store food for only a few hours or days, while others may do it on a seasonal timescale. Many carnivores, such as foxes and leopards, are opportunistic hunters so might stash or bury surplus prey and return to eat it a few days later. Jays and squirrels bury enough nuts to get them through the winter.

Hibernation

Hibernation is an extended period of deep sleep, or torpor, that allows animals to survive winter extremes. Reducing metabolic rate and lowering body temperature enables survival through cold periods when food is scarce or has little energy value. Hibernating species usually work hard to build up large fat reserves before they bed down, and subsist on this during their torpor. They might wake up at intervals to defecate or top up on food.

Migration

Migration is the usually seasonal movement of animals in pursuit of food, suitable breeding sites or to escape bad weather or other environmental conditions. Mass migrations – such as the wildebeest crossing the Mara River, or Pacific salmon heading upstream to mate – create some of the world’s greatest wildlife spectacles.

Why is Britain a wildlife migration hotspot?

Poisonous

Poisonous animals contain or secrete toxins and need to be touched or eaten to contaminate their victim. This is different to venomous animals that actively inject a toxin into their the victim. There’s a wide range of often highly complex poisons in the animal and plant kingdoms, all of which are used for defense. These poisons can paralyse, stun, cause tissue death or outright kill their victims. The effects depend on the type and concentration of poison and the amount delivered relative to the size of the victim.

Predation defence

Predation defence comes in many forms: physiological, anatomical and behavioural. Physical defences such as spines and armour are obvious adaptations, but other defences can be more subtle and surprising. Whether it’s avoiding detection through camouflage and mimicry, chemical defence through being poisonous or exuding irritants, it’s all about one thing: avoiding being eaten. Some animals rely on increasing their chances of detecting predators by living in groups and using alarm calls to warn each other of danger.

Shedding body parts

Shedding body parts, or abscission which means cutting away, is the process by which plants get rid of entire organs that have been damaged or are no longer needed. It includes the dropping of leaves, flowers and fruits such as in autumn when deciduous plants drop their leaves in response to the onset of winter. Fungi and even some animals shed body parts for different reasons. Lizards drop their tails when threatened by a predator, stags cast off their antlers after the rut and snakes shed their skins.

Torpor

Torpor is a form of sleep that helps animals conserve valuable resources in times of stress, such as in cold or very hot, dry weather. Body temperature drops and the heart and metabolic rates slow down so that less energy is needed to stay alive. Animals can stay torpid for short bursts, or go into long-term torpor lasting weeks or months, known as hibernation (winter) or aestivation (summer). Animals in torpor are far more difficult to wake up than animals in normal sleep.