Weight Management Training Demystified

Weight Management (WM) and Food Management (FM) are used by animal trainers every day; however, this is something many experienced trainers only understand the basics of. This means that when newer or lesser-experienced trainers set out to train an animal using these techniques they often do not fully understand what they are doing right or wrong, why it is or is not working for them, and how to improve their training skills altogether. I train many birds for free flight each year and often times when training an older bird, wild caught, or parent reared bird, I will utilize WM, because the animal with a challenging background normally sees you as something to avoid in the beginning and this helps to change that and allows you to build a trainer/student relationship, as well as properly motivating the animal to respond to your cues and actively seek direction as a way to earn rewards. Both techniques are using Primary Reinforcement so I will not discuss Secondary Reinforcers here.

Simply put, the most common form of Food Management (FM) is either 1: making it so that the bird ONLY eats during training (popular with early Behaviorists such as B.F. Skinner while he trained animals in a laboratory setting, they would become conditioned to perform a certain behavior such as pushing a lever which would earn them a reward - this was NOT normally requested of the animal by the trainer or done on cue), or 2: you discover the animals’ favorite food items and only offer those during training - meanwhile the bird is given less desirable food items that it can eat at its leisure. A good example where #2 is useful is when we begin training a bird who was previously fed an all-seed diet, we would convert the bird to pellets which it would view as less desirable than the seeds and therefore it would then value the seeds as a reward during training. The animal would ONLY get the seeds during training sessions. They can still have all the pellets they want and can eat all day, but when done properly they are still sufficiently motivated to earn the seeds even with a visibly full crop in some cases.

Weight Management (WM) on the other hand is FM taken a step further; the trainer carefully maintains the animals’ weight within a certain range, often called a “target weight”, “working weight”, “fly weight” or “flying weight”. It is hard for novice trainers to imagine working with a freshly caught bird of prey for example, but professionals deal with these birds all the time. The animal might have been flying wild only a very short time ago and often has a natural fear of humans. Weight Management is crucial to those practicing Falconry or working with performing birds that will perform high-profile behaviors where the bird is given lots of choices as to whether or not they will continually behave the way we desire them to. If you are giving a presentation and the bird flies off, the entertainer or trainer giving the presentation can call the bird back at will if the animal is trained properly. They willingly return because doing so earns them a food reward. The goal of a trainer who uses WM should always be to fly or work the bird at the highest weight possible while still maintaining good responses from the bird. A bird flown at too high a weight may become unresponsive. They can start doing their own thing and ignoring the cues we give them which is bad for all involved.

There are many opportunities to make mistakes and the most common is to underfeed or overfeed the bird. Disaster can occur either way so attention to detail is key. Smaller birds especially will need to be weighed as much as 3 times per day in some cases to accurately gauge and control the weight within a certain parameter. Sometimes maintenance within a 10^th of a gram is required for smaller species, so it can be very intimidating. Do not make the mistake of thinking the fly weight will be the same with every member of a species, for example, many people see me flying a bird and wish to do the same with their pet back home and I get asked questions such as “What is the flying weight for a Galah”? The answer is that it will be different with each bird and even changes from time to time with an individual animal as we “fine tune” them to perform the best they can (which is a constant process). A bird flying at 86 grams at one point in time might be flying at 78 grams later on and again at around 93 grams only a few months later. Fly weights should never be static. Again we should always be working towards flying or working at the highest weight possible. Once we find out a good working weight we ever so slightly begin to raise them up until eventually they can be flying well above the weight they would be at even if they were allowed unlimited access to food all day every day.

Before we begin training a bird using WM we first have to record their “ad lib” weight, which is the weight of the bird if it was on “free-feed” or “feed-up” (free-feed is allowing the bird unlimited access to food and feed-up is when we allow the bird to eat as much as it wants a few times per day but we remove the bowls to prevent spoilage etc in between feedings.) Measure the weight of the food the bird is eating each day so you know exactly how much he is eating to maintain the ad lib weight. Once we determine the ad lib weight and the amount of food required to sustain that weight we can begin training using WM.

When we first begin the bird will typically shy away or bate or even nearly injure itself trying to avoid you in some cases. This is normal when working with wild-caught birds, fearful birds, rescues and so on. At first they might not even take a treat from your hand when you offer one freely but this is normal when working with challenging subjects and you shouldn’t let this discourage you. As the days progress the animals’ natural motivation for food sets in and this becomes a thing of the past as they come to see you as pleasant (a food source) instead of something they need to fear or avoid. It is amazing to have a bird take its first hops to your arm when they were viciously attacking you only a week before.

The following is a demonstration of Weight Management with a Greenwinged Macaw

Say the ad lib weight was 1000 grams when you first start. The bird is fed equal portions of seeds, pellets and vegetables, yet when given a choice he prefers the seeds and eats them first – so these will be reserved for training only and he can have the pellets and fruits/vegetables left in the cage or aviary to eat at will. The bird tries to avoid you as soon as you walk in the room and it won’t even take a food treat from you even though it has not been fed yet this morning. You immediately drop a treat in the bowl and leave the room which ends the session on the best note possible. The birds’ weight is dropped 15 grams by reducing the amount of food given (pellets and vegetables are reduced, the seeds remain the same amount) leaving his new target weight at 985 grams. That might seem excessive but bear with me; the drop in weight is only just over 1% (and usually the bird is a bit overweight before training begins). After trying this weight again next day it is slightly more responsive but only for a moment so the weight is lowered again by another 15 grams to a target weight of 970 grams that the bird will work at the following day. That is exactly 3% reduction in weight from the original ad lib weight where the bird was allowed to eat as much as it wants but the results are already very noticeable the next day. You are able to begin training the flying recall indoors for a short time before it becomes full. Since the bird only remained responsive for a short time we again decrease the weight by 10 grams leaving his new target weight at 960 grams. Now the bird is performing reliably for short sessions flying Point A to Point B Recalls on cue (flies to you when asked) indoors for a few days and he really seems like a new bird. The animal has transformed from fearful or aggressive bird into a bird that reliably performs a behavior on cue. We have achieved this by simply reducing an already overweight birds’ body mass by only 4%.

We maintain him at this weight until eventually the bird is introduced to a new handler. Upon introduction of the new person the bird becomes unresponsive and we observe a breakdown in his behavior. We again reduce the weight, this time by 10 grams leaving his new fly weight at 950 grams. He does poorly over the next few days so we once again reduce the weight by 10 grams leaving him at 6% less weight than free-feed and weighing 940 grams. He improves remarkably and even when we move outdoors without restraints he is reliable. We teach him to fly from A to B on cue, Station on a platform above the stage, fly from trainer to trainer and he is right on target learning quickly and becoming increasingly confident when exposed to new and different objects and situations.

Here is where the more experienced trainer will begin slowly increasing the birds’ weight, while the new or inexperienced trainer keeps the bird at his target weight of 940. If you paid attention you will notice we dropped the birds weight in chunks of 10-15 grams each time – but now that we are raising it back again we do this very slowly and meticulously because we increase the body weight at a much slower rate than when we decrease the weight. You do not want the increase in food/weight to be noticeable to the animal. So we only raise the bird 1-5 grams a day. We have him working well until we get all the way back up to 985 grams, when we begin to train a new behavior and the bird needs a bit more motivation. We reduce him to 975 grams and the problem is fixed – but the lesser experienced trainer is still working the bird at 940, so he drops the weight to 925 grams while my bird is performing the same quality at 970 grams . That is a difference of 45 grams and we have only just begun. Now we introduce the bird to crowds, cameras, lights and so forth. I had increased his weight over time to 1005 grams and he was working fine until now. I reduce his weight to 995 and the problem is fixed for my bird – but the other trainers bird is still at 925 and is still reduced further to 915. Now we are at a difference of 80 grams between my bird and the other trainers’ bird. I slowly increase the weight over time all the way until the bird is flying at 1025 when he finally gets unresponsive and/or responding too slow to my cues so I cut him back 10 grams and he is performing superbly at 1015 – 100 grams heavier than the bird trained the old fashioned way and 15 grams ABOVE the ad lib weight that he would be at if he were just left in a cage eating all day. How is this possible?

The secret is that there is a “mental hunger” that can be used. The birds’ weight is reduced in quick, noticeable increments but when we increase the weight it is not noticeable, so even though the bird weighs 1015, he is still mentally working and flying at 940 grams. This psychological hunger was first used by trainer Steve Martin to my knowledge and is very important to use because having the animal at higher weight means the bird is healthier, less prone to disease and infection etc. I can’t stress enough that we want the bird flying at the highest weight possible. Flying at the highest weight possible is the most positive, least intrusive solution and that should be the goal of all animal trainers across the globe, regardless of the species of animals you are working with. From raptors to penguins to parrots, all of these will respond to this technique. It was my hope in writing this that the people wishing to train birds using WM would have a decent starting point explained by a professional member of IAATE (International Association of Avian Trainers and Educators) and for those of you who are already utilizing weight management I hope that the idea of psychological hunger finds its’ way into your “toolbox”. Food Management, Weight Management, even food rewards themselves are not the end of the road for the avian trainer. Always strive to explore new territories and grow.

Happy Flying!

-Chris Harris