Racing Pigeon Digest Featured Article

Back To Archives

Pigeons and the Conditioned Reflex
By Rod Adams

It all began with dogs, Pavlov's dogs.

Ivan Petrovitch Pavlov (1850-1936) was a famous Russian scientist who was Director of the Physiological Laboratories Institute of Experimental Medicine and Academy of Sciences, Leningrad, Russia. He won the Nobel Prize in 1903. It is pretty much common knowledge that he did most of his experimental research using dogs as his laboratory animals and that he could make them salivate profusely simply by ringing a bell.

But what is not so widely known is how and why this came about. Any real understanding of the processes involved is dependent upon at least a working knowledge of nervous reflexes in general and conditioned reflexes in particular.

Their whole study was initiated by two very simple experiments carried out by Pavlov himself. He found that if he introduced a mild acid solution into the mouth of a dog it produced the usual defense reactions of active movements of the mouth to get rid of the solution and a copious flow of saliva to wash it away. But if he repeatedly rang a bell just before introducing the acid as before, after a while the sound of the bell alone would produce the same reactions of mouth movements and salivation. Quite obviously two different mechanisms were involved but what brought the second one about? And anyway, what relevance has all of this to the sport of pigeon racing? And how important is it to the fancier to know about it?

In an attempt to explain what is, after all, a fairly complicated process (so that fanciers can decide for themselves on the relevance and importance of the conditioned reflex) we must begin at the very beginning and first deal with the straightforward nervous reflex.

What is it? Well, in its simplest form, it is an inborn, involuntary response to a stimulus. Perhaps the most well-known reflex of this type is the knee jerk used by doctors when testing the nervous systems of their patients. The patient sits with legs crossed and the doctor taps the uppermost leg just below the knee with a tendon hammer and if all is well the leg from the knee downwards involuntarily kicks sharply upwards.

This is a pure nervous reflex and it happens like this. The receptor (a part of the muscle in the thigh which is stretched by the tap on the tendon) receives the stimulus (the actual tap), a nerve carries the message to this effect to the reflex centre in the spinal cord which in turn sends a message back, via another nerve, to the effector (the thigh muscle proper) which contracts and moves the leg.

All this happens very quickly (much quicker than if the patient were asked to move the leg voluntarily on a given audible signal) because of the relative shortness of the nervous pathways involved. This is because the pure reflex is acting directly through the spinal cord whereas the voluntary action is via the ears, brain and then the spinal cord, which of course is a much longer route.

All the important bodily functions such as the movements of respiration, digestion etc. are controlled through reflexes, some of which we, as human beings, are aware of. Others we are not.

So in the first of Pavlov's experiments he was demonstrating exactly what I have just written about. The pure, unconditioned reflex. A reflex produced without any preparation. He put the acid in the dog's mouth and the dog reacted reflexively. In the second experiment, however, actual sound was needed to produce the same effect. In other words, the difference between a nervous reflex and a conditioned reflex is that nervous reflexes are inborn but conditioned reflexes depend upon previous experiences. Actually, conditioned reflexes probably form the basis of all training in our birds but it is not easy to establish exactly where reflex or involuntary behavior ends and where pure voluntary behavior begins.

What then is a conditioned reflex and how is it set up? As a simple example (and because Pavlov's work was on salivary secretion in dogs) it seems logical to look at this first but as all conditioned reflexes are formed on the basis of unconditioned reflexes this is where we must start.

Food enters the mouth and stimulates the actual nerve endings. Messages travel down the taste nerves to the salivary centre in the brain which in turn sends messages back to the salivary glands to start a flow of saliva. All very simple. And completely involuntary. But, and this is important, at the same time the sight of the food becomes associated with its taste and as well as messages going to the salivary centre in the brain they go from the eyes to the visual centre (again in the brain) and these two centers become linked forming what are known as "association pathways" in the brain, so that, eventually, the sight of food alone will produce salivary secretion by acting through the visual centre to the salivary centre then to the salivary glands with no actual stimulation of the nerve endings in the mouth by food having taken place.

This then is a conditioned reflex. A reflex conditioned by the association of taste with the sight of food. In Pavlov's dogs the association was the sound of the bell and dilute acid being placed in the mouth, so that in time the sound of the bell alone will produce the normal salivary effects.

Equally well the smell of food, the thought of it or any sound associated with it can establish a conditioned reflex of this type. Conditioned reflexes can be similarly established to many things other than food but hunger is a very powerful driving force in most organisms and the vast majority of fanciers try to control their birds, if not solely by food, then certainly through it. In a hypothetical perfect environment an animal could theoretically survive on its unconditioned reflexes alone but in the ever-changing environment that actually exists without conditioned reflexes it could not hope to survive. In the wild a pigeon could not live by just eating what happened to be in front of it. It has to be able to "know" how to find its food first, and then how to eat it. In other words the reflex act of eating is by itself useless. There must also be present the conditioned reflex of knowing where and how to find its food and which "clues" or conditioned "signals" will eventually lead to it.

The commonest, most basic, conditioned reflex utilized (unwittingly or not) by pigeon fanciers is the one produced by the association of food with a particular sound, usually a whistle, which is used to call the birds into the loft. Ideally it should be set up in pigeons at the age of weaning and reinforced by regular use thereafter. This association of food with a signal is produced quite simply by repetitive calling, whistling or even the waving of a handkerchief just prior to, and during, feeding.

This obviously becomes associated with food and thereafter it alone should suffice to induce the same reaction as feeding proper would do. Bring the birds into the loft. What matters most about setting up a conditioned reflex is eliciting the desired response.

Setting up the actual conditioned reflex can and often does occur without the fancier being aware of it. So, in this case the end effect of setting up this particular conditioned reflex has to be to bring the pigeon into the loft, hungry or not, or it is of no use to the fancier.

In the initial stages therefore the feeding-calling procedure must be carried out well inside the loft and only there as the call has to be associated here with a particular place as well as with food and feeding in general. This is what really matters. Likewise the signal or call has to remain constant for it to be really effective and as fanciers know only too well (in the case of a vocal call being used) the human voice can vary considerably under conditions of excitement or stress! A recommendation perhaps for the use of mechanical whistles, a rattle or even a bell. At least they ensure constancy of call and guarantee that if several people are involved in the day to day loft management the signals remain exactly the same.

It is only a short step from the conditioned reflex just described to producing another food-based one initiating good fast trapping, especially with young birds. The idea is to get the pigeons to associate food with the urgency to get home and into the loft as quickly as possible. It is very easy to put this idea into practice. One such system is this: shortly after weaning the youngsters are let out of their compartment always using a door and with no food call being used. They are let back in always via a trap or box-let (being put through this by hand the first two or three times if necessary) with food awaiting them inside and this routine is adhered to inflexibly throughout their young lives.

Simultaneously in these early stages the conditioned reflex to the food call is initiated by being inside the loft yourself, beside the corn tray when they come in. Thereafter this call can be used to get them into the loft proper they soon associate the food call with the need to get back into their compartment and knowing how the trap works will run through it in response to the call. This is kept up on a daily basis until their training program for racing starts.

In order to reinforce your control over them young birds should never be trained until they have taken what voluntary exercise they will and are hungry. The last thing any fancier needs is for his youngsters to take their normal complement of exercise over strange territory before coming home! Young birds must be taught that when released from the training or racing basket they must take the shortest way home and at the fastest possible speed. It is easier by far to get slightly tired and hungry youngsters to do this than those with corn in their crops!

So the system is as follows. Youngsters are given their normal early morning exercise and only lightly fed, then given their normal evening fly and taken away immediately afterwards for the training flight. Whilst they are away their food is put into the compartment and the loft got ready, exactly as it would be on race days, trappers and all.

Upon arrival the youngsters are got straight in using the food call and the trap and fed up for the night. This process being repeated for every training flight. In essence they are either in the loft resting or feeding or racing to it to feed and rest. There is no aimless wandering home half-fed or mooching about outside of the loft.

This process will pretty soon have them arriving home hard and fast from training flights and fairly rushing through the trap to be in. They now associate racing home with food and the need to get to it quickly.

You will then have established another useful conditioned reflex. It is relatively simple to reverse the process. Letting them out through the trap and not via the door inhibits their normal routine of out through the door and up into the sky. They will not associate this unfamiliar means of exiting the loft with the need to fly. With a little practice the fancier will find out that it is now possible to let them out in this way even when they are fully fed and to get them in at will in the usual way by using the conditioned reflex described earlier!

When you can do this you will have established absolute control over your birds. And you will be well satisfied. Take it from me. Finally, it is probably worth mentioning that once the youngsters have been taught to race straight home and have been at it for some time it becomes unnecessary to make them have their usual exercise before going on a training flight. They can then be taken straight from the loft.

As I wrote in a previous article, "The Home Environment," forced exercise can likewise be controlled by setting up the required conditioned reflex. This time not by using a food/reward system but by associating an unpleasant stimulus with the need to fly. This unpleasant stimulus need be nowhere as near drastic as the mild electric shocks given to rats when attempting to teach them to correctly negotiate a maze (or when producing a conditioned reflex in them for one reason or another) but some kind of stimulus is initially necessary to go with the signal.

It is unreasonable to chase pigeons around the loft with the doors open then expect them to come in immediately when asked to do so. All this produces is total confusion in the pigeons causing them to become insecure and weakens their attachment to the loft.

They should be put out as gently as possible to fly and the door closed. The actual signal used can be a flag flying, a bucket outside the loft or simply the closed door itself. The initial unpleasant stimulus need be nothing more than say a noisy clapping of the hands, flag waving or the throwing of a tethered tennis ball at them whenever the flock looks like wanting to land.

After sufficient time they will come to associate the signal with the unpleasant things that have happened to them when they are out at exercise and will react to the signal alone by flying for as long as they can see the it. And then no chasing them around will be necessary. Getting them in is simply a matter of removing the signal, opening the door and giving the food call. The response will be immediate and total. It is that simple.

The only note of caution is that like all conditioned reflexes a degree of reinforcement is necessary from time to time. Without an occasional reminder that the original unpleasant stimulus is still there the intensity of the conditioned reflex will diminish and the response will become poorer. The pigeons will then begin to ignore the signal and you will have lost your control over them.

One important reaction, usually massively oversimplified, is that known as the "fight or flight reaction." This enables people, animals and birds to react effectively in emergencies, in circumstances demanding special efforts, or in stress situations. It is a nervous reaction involving the release of adrenaline into the bloodstream. This causes the pupil of the eye to dilate and admit more light, increases the blood supply to the vital organs, causes the blood sugar levels to go up and the skeletal muscles to tire less easily and thus to function more efficiently. It is a naturally occurring reaction, one which enables our pigeons to successfully face emergencies.

But, and it is a big but, it is a reaction which can be unwittingly conditioned to occur completely unnecessarily through the actions of careless fanciers causing fear to be associated with these. For example, nobody has ever been killed by the sound of a car horn, but this noise occurring unexpectedly behind someone (even someone who has never been in a car accident) will produce all the classic effects of the "fight or flight reaction," simply because the person involved associates that particular noise with cars which they know fine well can kill. They have been conditioned to the noise of a car horn meaning danger and will react to it accordingly. This kind of arousal stimulation can be modified even if originally it was an inherent one.

For instance young pheasant chicks which have never ever seen a hawk will react by "freezing" or running for cover if any silhouette resembling one (short neck, short wings, long tail) is passed overhead but later in life experience modifies this reaction and they can very easily differentiate between the classical hawk shape of the Sparrow hawk and the very similar shape (to them) of the Cuckoo and they will react completely differently to the latter.

The big gulls are not natural predators of pigeons. Nevertheless pigeons will show alarm if one flies suddenly overhead calling and with neck outstretched. They may well flee in panic displaying the "fight of flight reaction" but close and continual exposure to this kind of unpleasant stimulus will modify their reactions. A friend of mine moved his loft from a garden site onto the roof of his riverside business premises. As there is a nearby fish quay and lots of tall warehouses there is a large and permanent population of big gulls breeding and roosting on the rooftops.

Initially there were problems with the pigeons bursting off in panic each time a screaming gull flew overhead but despite a couple of deaths caused through actual gull attacks the pigeons became accustomed to the gulls though remaining wary of them. The situation was described to me as "now serious but not desperate like before." The young pigeons, of course, reacted much more strongly than the adults which is exactly what you would expect. Strangely enough the form of the racing loft remained fairly constant. Probably the result of the birds having had all of the close season to accustom themselves to their new surroundings and new dangers.

The most threatening thing to a pigeon is something suddenly appearing above them in a downward dive. As this is a common form of attack used by aerial predators it will induce panic in the birds even if the diving bird happens to be another pigeon which the flock just has not seen coming. The initial work on this form of behavior was done using captive geese held in pens in an open field. The investigators used a cable strung between two trees to slide their various bird-shaped cutouts along and noted down the reactions of the geese to each shape.

One day a shape that the birds had never previously reacted to, a round disc, fell off the cable near to the pen causing absolute chaos. The geese were reacting to this "harmless" shape dropping down fast towards them exactly as they would do to an aerial predator. These same geese also demonstrated how easy it is to accidentally set up a conditioned reflex. To send their shapes along the wire the researchers had first to climb up a tree. One pen of geese quickly associated this with the hawk shape passing overhead on the wire and thereafter produced the alarm reactions whenever an investigator climbed the tree, long before the hawk shape appeared. They then had to be removed from the experiment! It is exactly this kind of accidental conditioning that fanciers have to be aware of.

Fanciers should do all they can to avoid undue stress by preventing the unnecessary occurrence of the "fight or flight" reaction. Especially if they themselves are unknowingly causing it by conditioning. The commonest cause of this fear reaction being set up is the association of something unpleasant with a signal. This can be seen most easily in those pigeons which seem to have an almost pathological fear of being handled.

I have written about the use of hands before and I make no apologies for doing so again. If a fancier uses his hands wrongly by chasing his birds around with them, by roughly taking hens off the nest, by carelessly grabbing them off the floor or from their perches then of course they will associate those hands with unpleasantness and react to them accordingly. Then when the fancier does need to pick them up they will panic and try to avoid the hands that are coming at them.

Conditioning has led to hands meaning rough treatment and discomfort. There is no way that these pigeons can know, as the fancier knows, what his hands are going to be used for on any given occasion. They will react as their conditioning has taught them to react. With fear. Now what is wrong with using a bamboo cane or a telescopic judging stick to move them about the loft and to put them out to fly using hands only for the good things in their lives, like giving them tidbits and playfully teasing them? The opportunities for unwittingly setting up these kinds of unwelcome reflexes are there all the time. Any unthinking action by the fancier, producing alarm that can be associated with anything definite can do this. Bad as well as good conditioned reflexes are equally easy to set up.

The brain can override the straight nervous reflex by conditioning. This means that to a limited extent it is possible to modify reflex action. Take the light reflex for example. This manifests itself as changes in pupil size if the eye is exposed to sudden changes in light intensity such as going from a dark room into bright sunlight or in changing from near to distant vision. It is a protective mechanism for the eye as well as improving its performance. It is relatively straightforward to associate some stimulus with the actual happening of the light reflex and for the person so conditioned to produce the reflex reaction in the absence of any need to do so. By signal only.

So it is feasible to produce favorable conditioned reflexes in our birds which can override any unfavorable "straight" reflexes to our advantage when training the birds to conform to a personal system of management. Reflexes can occur at all levels of the brain and spinal cord. Swallowing for example is an act initiated voluntarily but once the food is in the esophagus it is then reflexively transmitted to the stomach. Vomiting is also a reflex action which in people can be caused by fear or disgust as well as by other physiological factors.

In pigeons (which do not have a stomach as such) the cause is probably irritation of the nerve endings in the crop or esophagus. Fear of course can have a similar effect in both man and birds, leading to vomiting, but the point I want to make here is that any pigeon that is vomiting is involuntarily carrying out a reflex response to some irritation and needs watching. Feeding by regurgitation as pigeons do is reflexively initiated and triggered off not by local irritation but by and in response to the begging behavior of their young.

Pigeons can be conditioned to respond to any shape, size or color. And to carry out certain actions accordingly. They have been successfully trained by conditioning them on a task and reward basis to sort out pills passing in front of them on a conveyor belt. They can be made very quickly to learn to peck at a lever or a button each time they see a pill that does not conform to the normal pattern. They have become conditioned to "know" that a peck will produce food. But only when a particular shape or color is on the belt.

The pecking action is the outcome of the association between food and shape or color. A similar exercise was once carried out where pigeons were trained to spot life-rafts at sea on the basis of the orange color of the rafts. Their visual acuity being far better than the human eye they were much more effective at this than the human observers. The mainly academic exercises carried out in this field have little practical value (other than to perhaps research psychologists) but it does illustrate the almost unlimited scope of the technique of conditioning reflexes in racing pigeons to the benefit of those fanciers intelligent and patient enough to master it. And many of them have done just that!

All pigeon fanciers (whether they are conscious of it or not) are constantly establishing conditioned reflexes in their birds. What is important is how this technique, which is vital to them, is established and reinforced in their birds. And to what end? To use Pavlov's own words "The mere accumulation of facts without a general idea in mind, without a plan, is a useless occupation." We all of us have access to the facts. How many of us, I wonder, have a plan?