Aaah, the aroma of rotting flesh. An irresistible smell if you’re a carnivorous insect. So, for the corpse flower or Titan arum – the world’s largest and stinkiest flowering structure – smelling like rancid meat is a great way to attract your primary pollinators. And it’s not just the smell of the plant that drives the insects wild. The corpse flower is even the same temperature and beguiling colour of rotting flesh. Extreme measures maybe. But because it only blooms once every seven to nine years, it needs to use every weapon in its arsenal to help ensure the continuation of the species.
An equally seductive, though more fragrant, strategy is employed by the bee orchid. Its flowers are designed to look like the females of a particular species of bee. When male bees are tricked into mating with them, they’re covered in pollen, which they then spread from flower to flower. Probably the result of a random mutation, over time, the flowers that most resembled female bees attracted more pollinators, even when they didn't produce much nectar. So, they reproduced more quickly with less effort.
Tricking pollinators into pollination using deception and mimicry is not uncommon. Another orchid that does this is the hammer orchid. Pollinated exclusively by thynnine wasps, its flowers resemble a female thynnine wasp and give off pheromones that lure males. When the hapless male attempts to mate with the flower, the flower swings over, flips the wasp upside down and straight onto the orchid’s reproductive parts. The male wasp doesn’t even get any sweet nectar as a reward for its pollination service – it’s effectively been duped by design.
The biological drive to survive shapes behaviours and, in the case of leaves, dictates shapes. Unlike many animals, which can change their behaviour or simply move in response to environmental changes, most plants adapt to changing conditions by changing their architecture. Take the Monstera or Swiss cheese plant. As a young plant, it has heart-shaped leaves. However, as it grows older and larger, it grows new leaves with holes and splits. Why? Because as a plant native to the tropics, it’s evolved to allow the sun to shine through the holes onto the leaves below. The holes also provide good drainage – important in a plant whose leaves can grow to 60cm wide.
Another popular household plant, the weeping fig, dramatically demonstrates the lengths it will go to, to adapt to its environment. What starts out as an attractive leafy plant can suddenly turn into a pot of twigs when it sheds all its leaves. The reason is almost always caused by an environmental change. The plant’s leaves are perfectly developed to suit a particular situation. When that situation changes, the plant’s survival is at stake, and so it grows new leaves better suited in size, shape and thickness to its new situation.
Talking of leaf size, there’s one plant that puts all others to shame – Raphia regalis. A species of raffia palm, Raphia regalis can be found growing in the moist lowland forests of the tropics and sub-tropics. Its huge leaves can reach a staggering 25m long by 3m wide, bigger than any other plant species in the world. Just carrying a single leaf would take around half a dozen people.
The size of a leaf as well as the angle of the dangle is related to a leaf’s function too. Sharply angled leaves are believed to reduce the amount of light that a leaf can intercept during the glaring midday sun, effectively shading itself. Large, broader leaves are better at absorbing more sunlight, rather like solar panels, making them ideally suited to darker environments, such as under the rainforest canopy. Long leaves help with temperature regulation, making them especially suited to hot conditions, while thin leaves help prevent water loss and are suited to dry conditions.
In many plants, whole leaves or parts of leaves, get modified to perform special functions – other than the normal ones, such as photosynthesis. The leaves of cacti for example, have been drastically reduced to sharp points or spines, to protect them from peckish predators. Photosynthesis takes place in the thickened green stems which are also used to store water. Incredibly, desert cacti can survive for up to two years without water.
Other plants living in extremely arid areas generally have highly thickened and succulent leaves for storing the limited supplies of water and to resist drying up. For plants in aquatic environments such as the floating fern, Salvinia, some of the leaves are modified into special roots to help the plant float on the water’s surface. And in climbing plants such as cucumbers, some leaves coil and form tendrils, which help the plant attach to a support as it climbs.
More ingenious still are insectivorous plants, whose leaves have been specially adapted to catch and digest insects. The leaves of the pitcher plant have been modified to form a jug or pitcher, the rim of which is alluringly colourful and fatally slippery. When the unfortunate insect landing there loses its footing, it falls into the pitcher to be consumed by digestive juices. A more famous carnivorous plant is the Venus fly trap. At the end of each of its leaves are two hinged lobes – lined with touch-sensitive hairs – and edged with spiny teeth, which can snap shut trapping the insect inside. It’s yet another brilliant example of form following function – of design genius by plants. And as designers, we could do a lot worse than take a leaf out of their book.
While most animal communication takes place between the same members of a species, it can also take place between different species. An obvious example is the communication between us humans and our pets. As we’ve shown, some animals are highly sociable and expressive, while others communicate only when absolutely necessary. Some animal species rely on just one method of communication to talk to each other, while some species use a combination. And the different messages animals send can be complex and varied, specific or general and even communicate different things to different receivers simultaneously.
Working out what animals are saying to each other isn’t just fascinating, it’s useful too. By understanding what messages animals are communicating, the greater our understanding of the world around us and the better we can look after it. Understanding animal communication can help us in the conservation of endangered species. If we know how different animals communicate, we can work out which kinds of human activity might endanger them further.
Cargo ships for example, make a lot of underwater noise and even engines from smaller boats can confuse or drown out whale songs and dolphins’ sonar, making it hard for these animals to survive. By carefully choosing where we locate shipping lanes or what types of boats we allow in certain coastal areas, we can help protect these animals and their habitats. And by understanding how moths communicate using pheromones, we can apply it to pest control. By recreating specific pheromones to lure destructive moths away from valuable museum objects, we can avoid using potentially dangerous chemicals. When it comes to animal communication we’re constantly learning. But one thing’s for sure. In the animal world as in the human world of design, there are many different and dazzling ways to express yourself. It’s about fully understanding who you’re talking to and finding the most impactful way possible to get their attention.