I would imagine that you'd probably get as far as Princes street, about a 800 yards from the station, before collapsing in a heap on the pavement, or if you were one of the guys down my pigeon club you probably would not even reach the end of the station platform.

Quite a tough test on one bag of popcorn and a glass of water, and yet that is the equivalent of what we ask our pigeons to do each racing season. For those who fly South road try an equivalent exercise, but this time take the train to Limoges.

So how does a pigeon do it? How does that small bundle of muscle, bone, air and feathers, fly distances as far as 500 mile and sometimes further, on a crop full of corn? It seems inexplicable that a pigeon could ever complete such a journey at all, and yet it can.

The answer is that pigeons have exquisitely fine tuned metabolisms. They can generate energy from their food in a highly efficient manner. In addition to this they have evolved ways to carry a great deal of stored energy onboard as fuel. Finally, during flight, they have a superb power to weight ratio.

By studying and understanding how a pigeon utilises it's food, stores it, and burns it up as fuel, we can modify and adjust the type of food with give depending on the type of racing we plan to do. This will get the best out of the pigeon allowing it to perform to its maximum capability.

A pigeon is a little like a machine and any machine that performs work needs energy. For example a car needs fuel such as petrol. The amount of fuel it gobbles up and how fast and how far it can go relies on several factors, how much the car weighs, how big the engine is, and how much the tank can hold. In addition the amount of fuel that the car consumes will be influenced by how efficient the fuel injection system or carburetter is, and how aerodynamic the body is, and whether there is a tail or head wind. Similar principals apply to the pigeon.

If it weighs too much, i.e. it is too fat, it will need to work harder just to keep it in the air, let alone, propel itself forward. The size of the muscles and heart, the pigeon's engine and fuel injection system will also make a big difference. Powerful muscles and a strong heart will pump fuel and oxygen around to maximum efficiency. A pigeon with a poor vascular supply, serving a small out of condition muscle, won't fly very fast for very long.

The pigeon's fuel tank will be equivalent to how much fuel it had managed to store on board. This can be in the form of fats that can be mobilised easily and carbohydrates stored as glycogen in the liver and muscles. The muscles hold most of the pigeon's glycogen, in fact two thirds of the total glycogen in a pigeon is held in the muscles. It therefore follows that the larger the muscles, particularly the flight muscles which are the biggest, the more glycogen the pigeon can carry. Training increases the size of the muscles and that is why it is an essential part of a successful racing pigeons management. So amongst other things, training makes one of the major fuel tanks bigger.

However, regarding fat deposits, if they are in excess, they can be very heavy, and too much weight would override any benefits that the energy they held, would provide. That is why, just the right amount of stored fats is important. Glycogen stored in the liver and muscles is very light compared to fats, but it can soon get exhausted if the race is very long. So fats will play a big part in a pigeon's ability to fly at speed, particularly over long distances.

You would have thought that the crop would be a useful place to store food as a useful source of energy, but this is not the case. Undigested corn weighs proportionately heavy for it's true calorific value. This is because it contains a great deal of waste material that cannot be used as fuel, such as the fibre. The pigeon first has to digest this corn, and extract from it, the useful components that it needs. Waste products are then excreted. During flight it is unlikely that this raw fuel can be mobilised while the pigeon is in flight. It will need to be absorbed and digested before anything useful can be made of it.

This is why it is inappropriate to put a pigeon into a race carrying a great big crop packed with corn. It could be argued that if the pigeon was due to be in the crate for several days before liberation that it might be an advantage to take a 'packed lunch' and indeed, if you could predict a long journey and then an equally long holdover then this might be a good ploy. However there is usually no guarantee that the pigeon wouldn't regurgitate the corn during the journey, and in any case, pigeons are usually fed during long holdovers.

The other major factor that will influence how much fuel the pigeon will need to burn during it's flight home is how aerodynamic it is. The car example can illustrate this well. Simply put a roof rack on your car and measure the drop in fuel consumption that occurs. It is the same with pigeons. A pigeon with an ungainly shape, course feather and poor aerodynamics will have to burn more fuel to maintain a good speed than say a pigeon with a silky smooth streamline profile.

This is why pigeons tuck their legs inside their under feathers whilst in flight. Aeroplanes adhere to the same principals when they take off. Raising the undercarriage reduces resistance during flight. This is particularly true when flying against a head wind.

During a long arduous flight, the overall package that is needed with any pigeon is a perfectly balanced power to weigh ratio. Again the car example serves well to illustrate this point well. Fill an old Volvo up with 5 burley pigeon fanciers and their luggage and drive against the wind to Blackpool and measure how much fuel you have to put in the tank. It will be considerably more than a single person driving the same distance at the same speed in a Mini.

Quite simply the Volvo has poor power to weight ratio. It is not an aerodynamically designed vehicle and the situation is made worse by the fact that there is a head wind, and in addition, it will be carrying a great deal of weight. This probably goes a way to explain why most successful distance pigeons have a small to medium frame, aerodynamic balanced shape and silky smooth feathering. In particular hens seem to fit this bill well, and this goes a way to explain why they perform admirably, in the distance races, in tough conditions.

One factor that contributes to the utilisation of energy by a pigeon is how much oxygen it can absorb whilst in flight. Large efficient lungs with a considerable internal surface area are essential for extracting the maximum amount of oxygen. This oxygen is required for 'burning' the glucose released from the stored glycogen. Again, the car example can serve to illustrate this point. A car with a highly efficient and properly tuned fuel injection system or carburreter will take the correct amount of air into the engine to mix with the petrol for perfect combustion. A carburetter with partially blocked jets won't take in enough air, as the car accelerates faster, and the engine will splutter and stall.

Similarly a perfectly clear and disease free respiratory tract is essential for the pigeon's breathing to perform to its maximum effectiveness. The pigeon has one additional aid to maximising air intake during flight. It has air sacs. These serve to briefly store and warm the air during flight so that the pigeon is never flying out of breath, with a deficit. The example that serves to illustrate this is with bagpipes. The person playing the bagpipes, fills up a reservoir or bag with air as a reserve. He or she then releases this air by pressing on the bag tucked under their arm. The bag is then refilled by the piper, when it is needed, during the performance. Air sacs in pigeons serve a similar purpose.

The added bonus of large lungs and big air sacs is that thy cut down the overall weight of the pigeon considerably. Widowhood flyers often comment that when their widowhood cocks are on form they blow themselves up like balloons and feel like they are made of cork. During the height of their sexual display behaviour they pump up their air sacs to maximum capacity. This peak in form is partly due to the increased ability of their air sacs and lungs to take in large amounts of air, for the maximum extraction of oxygen during a race.

Now when this oxygen combines with the glucose that is being liberated during flight, energy is released. This energy is released as something called ATP. It's a chemical which can hold large amounts of energy trapped within it's chemical structure to be readily released when needed. So why have the energy produced from glucose locked up in ATP? Why not just release it to be used straight from glucose? Well the energy has to be transported to where it is needed within the muscle cell and ATP serves to do this.

To give you an idea of how much energy is needed during a pigeon in flight, a working muscle, during flight, needs a 10,000 fold increase in the amount of ATP generated per minute compared to when it is resting. When you consider that 1 molecule of glucose is only capable of producing 38 molecules of ATP, you can see that a pigeon requires an awful lot of glucose for every minute that it is flying. Furthermore, when you consider that a pigeon can be in the air for up to 12 hours, that's 720 minutes, that's 189,473 molecules of glucose, just to get it home.

Luckily glucose is not the only source of energy to make ATP. In the chart below you can see that lipids are a much richer source of energy. Lipids are released from fats just as glucose is released from glycogen. The breakdown of Lipids will generate energy and this too is held within the high-energy phosphate bonds of ATP. In addition to both these energy sources, pigeons can also utilise proteins as a source of energy. This is usually as a last resort when all the glucose and lipids have been used up. Which makes sense, as the protein is primarily present in muscle, and the pigeon does not want to start using up its muscle unless it is absolutely necessary.

Glucose gives 3.75 kcal/g
Protein gives 4.1 kcal/g
Glycogen gives 4.3 kcal/g
Lipid gives 9.5kcal/g

You can see from this table that 1 gram of lipid holds much more useable energy than 1 gram of glucose. This explains why many distance flyers first load up their birds with carbohydrates before a big race but then super load with fats using such things as peanuts. It also explains why distance fliers will train hard but then allow a resting period before a long race. This allows a small reserve of fats to build up. Using a hen that is sitting eggs for 10-14 days is a prime way of guaranteeing rest and the build up of a useful fat reserve. However it is essential to get the amount of fats stored on board, just right.

One further aspect of energy utilisation is that energy is not only released and used for mechanical work such as flight but also for generation of body heat.

During muscular activity, the major portion of energy appears as heat and during rest nearly all the energy generated is released as heat. It is essential that a pigeon does not get overheated when flying. However, a flying pigeon will remain relatively cool because of the cooling effect of air passing over its body as it flies. To help with this cooling, the lungs and airsacs provide a large surface area from which to dissipate heat as the pigeon breathes in and out.

One major consideration is that pigeons can also lose a large amount of moisture when flying in hot conditions, this is why it is essential that it gets a good drink whilst in the transporter. Also, it is to its advantage if the pigeon can get an early liberation before the sun gets too hot in the day. A transporter full of pigeons sitting in the mid day sun soon heats up. Some more modern transporters particularly some of those in Belgium and Holland have in-built ventilation fans to maintain a good airflow and hold temperatures down.

I have mentioned that pigeons will as a last resort use proteins as a source of energy. Degradation of tissue proteins, primarily those of skeletal muscle, provides amino acids for manufacture of glucose in malnourished pigeons. That is why pigeons that fly on, after having exhausted all their glucose and fats, start to breakdown their muscle to use as fuel. This happens when birds try to fly long distances without adequate fuel reserves and also when youngbirds that get lost keep flying on without rest. Very often these birds are found 'flown out' and examination of their breast muscle shows it to be dramatically reduced.

So how can a pigeons energy reserves and power to weight ratio be influenced by good pigeon management? Well let us consider what happens during two very different forms of management.

When fanciers fly sprint races using widowhood cocks, they usually adhere to a similar basic management system. They generally fed a lighter breakdown mixture at the beginning of the week. They also let their pigeons out twice a day for exercise and they keep the cocks in a temperature stable closed in loft. The cocks also only see the hens as little as possible.

A lighter breakdown mix at the beginning of the week will cause a widowhood cock to burn up any lactic acid within its muscles that has built up after a race. Lactic acid is the waste product that builds up during exercise. If this is present in too high a quantity during flight the pigeon's muscles will begin to hurt. A similar feeling in humans is when you are running and you get a 'stitch'.

A stable loft temperature will allow the pigeon's metabolism to fall into regular low-key tick over. If the temperature fluctuates wildly the metabolic processes will be up regulating then shutting down in cycles that will disrupt the use of energy efficiently. Any fuel will start to be burnt off as heat. When the pigeon is then asked to do work i.e. fly, the metabolism will be in - energy for heat mode rather than - energy for work mode.

During widowhood, by keeping the cocks separate from the hens their sexual ardour will increase. Sexual hormones will be released. These result in behavioural changes such as an increase in aggression and a change in metabolism. Circulating adrenalin becomes elevated which stimulates the metabolism to go into a higher gear. Too much will cause problems such as loss of appetite and wild erratic behaviour. This sometimes happens with yearlings whose immaturity and lack of experience cause them to behave unpredictably.

Similar changes can be seen in young people as they go through puberty, their newly secreted hormones cause all sorts of irregular behaviour that any parent can tell you about. However in pigeons this inexperience sometimes holds advantages during some races. Whilst older wiser pigeons stick with the crowd, cruise home or simply rest over when the going gets tough, yearlings will fly on, often striking off on their own to get home with great determination.

Natural flyers use different ways to stimulate a pigeon's metabolism to maximum efficiency while allowing the pigeon to store large amount s of fuel, particularly in anticipation for the longer races. To do this natural flyers will train their pigeons to get them fit, and capable of the task in hand. By then getting them to go down on eggs the pigeons metabolism will go up a gear. Sitting causes the release of hormones that prepare the bird for the task ahead.

Firstly the bird's body temperature must increase slightly so that the incubation of the eggs will be successful even in cold weather. To get this raise in body temperature the metabolic rate increases. This is why sitting pigeons often seem to gleam whilst on the nest. Their feather shine and their eyes sparkle with condition. The increased metabolism is also preparing the pigeon for the other tasks ahead that go with rearing youngters, such as feeding, flying great distances to get food and defending the nest from outsiders. Fats are readily stored during this sitting period particularly if the feed is rich and plentiful. To prevent too much fat being stored fanciers will give the birds short tosses back to the nest, which also instills great homing motivation.

When natural flyers have pigeons that fly better when returning to youngsters they are feeding, they have found ways to prevent the pigeon, that is due for a big race, giving up all it's fuel. They use tricks such as switching large youngsters for smaller ones before sending the parents off to a race. This means that the cock or hen is gorging food to feed 2 big appetites and yet hardly has to give up any food, as the smaller youngbirds do not need as much. Alternative ploys are to get surrogate parents from another nest to feed the youngbirds and then switch the youngbirds back to their original parents. The food-laden parents then try to feed the youngbirds but they are already full.