The outside world at this time of year is drab and frozen. The winter air, when not soggy with rain, tends to be thin but crisp. Against the dun-grey skies the leafless trees are etched in black ink, seemingly asleep. This year we have had unexpected visitors from Siberia; late frost, ice and deep snow. Snow may be a rare treat to our children, but to birds it means more hardship as feeding and drinking becomes even more difficult. It is often a matter of life or death. Freshly prepared food (softened cookies mixed with a large amount of beef dripping and dry mealworms, laced with peanut butter and a handful of sultanas), plus two types of premium seeds: sunflower heads and one for my robin, are received enthusiastically. Warm water for drinking and washing is also appreciated as it warms their feet and bodies when they sit on the container edge. Providing for our feathered friends, as ancient Egyptians called birds, is of great importance as many independent surveys report rapidly disappearing wildlife in all European countries, irrespective of their level of industrialisation. Some people may think this is nothing to do with their own backyard. But let me ask this: when did you last see a song thrush or a redwing in your garden?
We may attribute diminishing wildlife numbers to factors such as urbanisation of open spaces and intensive farming, but I am convinced that disintegration of our communities must also contribute. Many years ago when we moved into our present home, I started feeding the birds in my garden. In the first few weeks I had only a few diners but as the winter progressed, the feeding table become so overcrowded that I had to open five more to cater for around 100 birds. But I didn’t have the same luck making new human friends because most people in my street don’t know each other. We are all busy working people but I cannot help regretting our loss of friendly community. In true community spirit, all of us could participate in creating wildlife gardens, and preserving our natural heritage for our families’ and our own pleasure. We are part of the same cycle that is continually renewed, thus ensuring that life on earth in all its variety, come spring, can begin again. If we don’t save our wildlife and our countryside, who will?
In one of her recent interviews Alison Steadman said that she loves watching the birds feeding outside her window, and that it gives her a warm feeling. I could not agree more. Observing the wildlife in our gardens or in the countryside also broadens our horizons. We begin to want to know more and learn why creatures we observe behave the way they do. Let me give you one example here. Many people ask this question: how do birds stay on their perches? All birds that perch are able to stay put on tree branches while asleep or in bad, windy weather thanks to a brilliant anatomical device. This device is particularly indispensable to all migrating birds during resting periods when exhausted after a long daily flight, they sleep heavily, often in hazardous conditions. In fact, this device is so good that sometimes a bird stays up on a branch, although it had died in the meantime. So what is it? It is a tendon called the flexor that extends from muscles in each thigh downwards, over the knee, down the length of the shank, around the ankle, and under the toes of each foot. They are arranged in such a way that the bird’s body weight, when bending the knee, causes the tendon to draw tight over the pulley formed by the knee, thus closing the claws. When the bird is asleep, and therefore in a relaxed state, this tight grip is so powerful that no matter how strong the wind is, it cannot dislodge the sleeping bird.
With the mystery of perching solved, I would like to highlight a different approach in research into animal psychology that has emerged recently and is greatly interesting. What we now accept is that we have a very limited knowledge of animals’ psychological abilities. It is not surprising because we still don’t fully understand the workings of a human brain. We all know the saying that to understand someone and his actions, we have to walk in his shoes. In reality, we often don’t apply this technique to human relationships, let alone to animal ones. Consequently, any research in animal behaviour will be flawed, if it is based on human perception alone. This was clearly illustrated in one documentary devoted to the testing of the intelligence of big primates. The researcher testing the level of understanding of human language in a chimpanzee was wearing headgear similar to that worn by the astronauts who walked on the moon. The purpose of the headgear was to prevent the chimpanzee from reading facial expressions, and the absurdity of this wasn’t lost on the animal, while the scientist was totally oblivious to it.
One of the favourite books in our family is the story of Peter Pan. To be able to fly above the rooftops, almost touching the moon, has been one of the oldest dreams known to mankind. Remember the tale of Icarus? Yet, it wasn’t until the end of the 19th century that we could at least begin the realisation of that dream. Why did it take us so long? Being able to fly is the most difficult of all methods of movement. It requires not only an enormous amount of energy and a very special design of the wings, but also a specific construction of the whole body. We still don’t know everything about a bird’s flying mechanism because our learning models, the birds, fly in so many different ways, depending on the type and family group of species. As we humans are not able to fly naturally, we don’t seem to have the same feeling, or inherent “know-how”. With the progress of aviation we have acquired an understanding of the way a bird’s body is designed. That is why contemporary aeroplanes are much closer in their outer design to the shape of a bird than the first planes were. Different types of planes reflect their specific flying method; for example a glider resembles closely the gliding flight of an eagle. We still don’t know how to fly by the action of wings alone. Our planes have to use the energy of the propeller and jet engine.
Apart from birds, the other creatures able to fly are bats, insects and flying fish. But only birds have achieved the perfection of this method of movement. How do they do that? Let’s start with a wing, which as far as body design goes, corresponds with our arms. In principle, a wing has the same bone structure as a human forelimb but the number of fingers is reduced to three, as is the number of smaller wrist bones. It is this reduction of bones, and the fact that the remaining ones are strongly fused together, that gives wing structure much greater power compared to that of the human hand. It also forms a formidable base for the most important and strongest of bird’s feathers – the flight feathers. A bird’s body shape is wholly designed for flying, from its hollow, flexible bones to its skeleton’s aerodynamic build that is specially reinforced to withstand the rigours of long-distance flying. Their internal organs are simplified and very light, as are the virtually weightless feathers. Many birds have sacs among the muscles or beneath the skin, and these serve as internal air conditioning which aid the permeated air chambers in the bird’s lungs to cool the body during the flight. But the secret of a bird’s ability to fly lies in the airfoil shape of the wings and the structure of its feathers which allows the bird to stay airborne as long as air flows over and under it. The flight feathers have to be strong to withstand and overcome the force of gravity, strong air currents and air resistance, and the bird’s own body weight. The different needs of various types of birds are reflected in their wing structure, but generally, they are arched in a similar way to our brows, and each flight feather has the flexibility of a spring. During the flight, feathers become either flatter or open, similar to window blinds, a design that was inspired by the attachment of flight feathers to the bird’s wing. At downstroke, extended wings create a large flat surface which catches the air and propels the bird up. As wings move up, they open spaces between its flight feathers, allowing air through. It is this characteristic ability of balancing the lift, drag and weight that enables birds to fly and keep level.
The movement of flying is difficult to explain in words alone, but understanding the complexity of the feathers’ design, internal as well as their external arrangement, shape and size, can at least give us a greater understanding and respect for nature’s wonderful way of solving problems; and it isn’t just “flying on a wing and a prayer”….
J.M. Barrie wrote: ‘The reason birds can fly and we can’t is simply because they have perfect faith, for to have faith is to have wings.’