Weight Management in Passage RTs

[Master Yarak]

Considerations of weight
Why do we weigh? Is it simply hunger that motivates?
What correlation is their between weight and hunger.
Survival is the basic drive in all animals. In predators it manifests itself in the killing and eating of other animals. Most predators kill only for food. This is true of raptors as well. They must take in more energy than they expend or they will starve. A bird at high weight will respond almost like a bird at low weight. Why? When you understand this, it makes perfect sense. Neither bird wants to waste energy. The fat bird is content to save the energy. The low bird has none to waste so he waits for a sure thing. Once the bird knows we always have food you can begin to raise the birds weight. Why? It requires little energy to aquire. The intake outweights the expenditure. It is my goal to have a bird kept in the condition of a tri-athlete not a high percentage of body fat, but still maintains some fat for energy expenditure.
Rhythm, it too is part of all things. It is part of the nature of Red-Tails. What is the most valuable meal to a Red-Tail? It is the evening. Why? It gets colder at night. The birds metabolism speeds up to maintain body temperature. If it wakes up in the morning already in the negative energy collum, it is in for a long day. You see them one place on your way to work and another on your way home. Morn and eve meals. By regimenting the bird's eating schedule we can influence that rythm.
That is why I weigh at the same time, and I fly at the same time. That can also add predictability, a rare comodity in this sport. It also allows a wider weight range. The bird can still be "heavy" and fly well if it is a afternoon/evening. Her rythm is telling her the dinner bell is ringing. All her drives are in place, yet she is not hungry... well not by her weight. Her stomach rumbles and tells her it has been 24hrs since her last meal. If she is not "fat" she will be well motivated. It relates to hunger drives without being too low. Even in good condition a bird that is "low"will not have much stamina. It will take longer for the energy to return after an unsuccessful chase. You will notice a rise in reckless attempts that seem hopeless. The bird is getting desperate. Not desireable for hawk or hawker. To me falconry is being a part of nature. That said I want to exploit the nature of this hawk. That is done through rythmic regimine. Like clockwork. That is how the state of "Yarak" is induced. The bird anticipates the hunt it becomes hyper-stimulated in preperation of killing.
Now dont get wrong their is some variation life is like that. If you make it a priority, all the time, you might be suprised by the results. This is applicable to all falconry birds. Weight alone is not always the answer. So many times their are other factors overlooked that contribute.
In conclusion, I would like to say that this is not a declaration of facts. Merely observations and recorded data. I am NO expert, just passionate. Their is more I could say but I am a very slow typist. I will however be pleased to clairify any points made or to give further explanation as requested. I hope this helps.
Yarak

[Weasel]

Good post. I had something similarly written on weight management on another thread regarding the difference between being at a weight and how you get to that weight. ;D

[Weasel]

Here is what I wrote in an old thread in the general link.


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I will simply state that there are many methods to find a flying weight but I chose a close variation of Gary's methods. The best way to say why a birds weight needs to be closely monitered is that they are an equivalent to an Olympic athelete. They need to be lean and focused on the job at hand. It is the equivalent of you skipping breakfast and lunch, by dinner time you could eat the @$$ out of a dead mule! You want the bird to be in great physical shape while being hungry enough to crash into quarry with reckless abandon. There is a fair gap for too high and too low in weight (thankfully) for the RT which is why it's a great bird to learn the skills of weight management.
If the bird is too fat, then it will take less chances at taking quarry because she feels that it's unneccisary at the moment to chase that hard to catch squirrel when she can sit on this tree and pounce on a rat. If the bird is too low you will have very similar signs(as I have seen first hand). They will really want the squirrel(or bunny) but are trying to conserve every ounce of energy for the absolute payoff, not a "possible catch" so the signs look fairly similar in too high and low. Trick is finding the mid point of these where she has the energy to fly at the intended quarry and not check off due to being fat and uninterested or lethargic in nature when flying because she is low. There are different things to look at in weight management as well as a number. If I had a bird at 1300g and her hunting weight was 1100. I could simply not feed her for a few days and she would reach that weight. The other method involves bringing the weight down slowly while feeding a rich diet to keep her metabolizm going so nutrients are being used not stored. After awile of doing this you will actually be able to drop her weight just as fast while feeding the bird as not. The benifit of feeding is obvious as her body is staying much more healthy as she burns the food rather that shutting the body down to conserve energy. This conserving will only lead to strange behavior in flighing and training. I'm sorry but this isn't easy for me to type out so I may be rambling on a bit so bear with me if you can make any sence out of it. If you can understand the difference between having a number and how you get to that number then things will go smoother and you will have a content and healthy bird. All in all I beleive that a good sponsor should be watching your progress and so make the decision as to what flight weight will be. Some birds are more pig headed that others and can really throw you for a loop by not reacting like "the book says" and it can lead you to make some serious mistakes in judging her weight. Alright, that's enought for now as I have already forgotten the original question?....?...?

[Bob Dale]

AT what point is the motivation of hunger replaced by the influence of operant conditioning?

[Weasel]

I'd guess that it will depend on the learning curve of the bird. My bird is used to hearing the call when food is around. She is hog fat right now at almost 1500g and will still fly to the fist sight-un-seen for food when she hears the call. I think that after the initial weight drop from trapping they learn very quickly what signals mean food as this is all they care about. when you raise the weight they do it from memory, not hunger. When I had my bird to 1550g she would still fly to the fist quite well but she would only pick at the food and not wolf it down like she normally does.

[Bob Dale]

Ok, i see. But you're talking about fly to the fist. Does that translate to flying at game as well?

[Weasel]

I guess they do to a point. Yarak's bird will fly at squirrels like it's the last one on earth within a 4-5 ounce window while hog fat. She doesn't respond to the fist as well at that weight, but she WILL nail a tree rat. I think this is burned into her mind that "this is what is supposed to happen" when we go to the woods.

[Master Yarak]

BobDale said:

AT what point is the motivation of hunger replaced by the influence of operant conditioning?

Well, that is not an easy question to answer. One of the determining factors would be the degree of the conditioning. I am not sure that it ever is replaced. What is does do is rewire the food program. The closer to starvation the animal gets the stronger the survival drives become. I THINK as the weight goes up and food drives recede it is easier to obtain the desired response
from the conditoning. I have sought to influence my bird as little as possible. The conditioning I have done is minimal compared to others. I rely heavily on the cyclical nature of the bird. Being very consistant has worked very well for me. I have chosen to sacrifce some control for weight. Prey drives are a strong motivator themselves in some animals. Look however in the variations of prey drives in the same breed of dogs. Just because it works for this particular bird does not mean it will for others. Operant conditioning when done correctly will remove that variation and thus produce more predictable patterns in behavior.....I told you it was a difficult question. Steve Layman seems to be on the leading edge of OC in raptors he would be a far better source of info on this topic than I.
Yarak

[Master Yarak]

*BUMP*

[alex2]

In Kestrels I dont believe you can have that much of a "window" for error when it comes to weight. 5g could be equivilent to 5 ounces to a RT.

Im not sure about being able to raise there weight after a long period of time either. Unless you give them a real work out each day and build muscle tone.
I dont know anybody that has kept a kestrel long enough to seriously lure fly it
or try flying at higher weights over a long period of time.

( just trying to shake the life back into this thread)

[bq93]

At the risk of getting lambasted for what I may be doing wrong I think it is important to get this stuff out there so that others can learn -

I think this has been one of the hardest areas for me to get. I know the bird is learning, but this is only my second year so I’m learning too.

I trapped my bird around Thanksgiving at 1600 g with a full crop and fat as a pig. It’s hard to estimate the weight of that crop, but she was down to 1400 g pretty quickly so I’ll use that as my starting point.

She still hasn’t made a kill. She is flying free, but seems to have a very narrow window as far as weight management goes. I had to take her down to 1050 to get her to fly to the fist. Although she is sharp (my sponsors observations) at 1100 she could care less. If she is above 1050 it has to be on the creance if I want to keep a bird this year. Even at 1050 she is not as aggressive on the lure as you would expect. She has shown some of the weak flying that comes with taking a birds weight down so I want to bring her weight up a little, but she is having no part of it. It looks like she is going to have to fly between 1000 and 1050 for now. I believe if I fly her higher than that she is on her way to Mexico.

Apprentices take note – keep a journal so you can remember how cold it was – how much you flew – how much you fed. There is more to this than just trapping a bird and going out in the woods. In fact those are the easy parts.

Feel free to fire away.

[Joby]

Sounds a LOT like my first FRT Catcher. She was trapped at 54.5 oz and ended up flying at 35.75. She only had a 10 gram window. Anything above and she would just sit. Anything lower and she was too low. She ended up catching two rabbits on our last two outings of the year, but it was a great education in the powers of careful weight management.
-Joe

[K9JaY]

iamtheweasel said:

Here is what I wrote in an old thread in the general link.


If I had a bird at 1300g and her hunting weight was 1100. I could simply not feed her for a few days and she would reach that weight. The other method involves bringing the weight down slowly while feeding a rich diet to keep her metabolizm going so nutrients are being used not stored. After awile of doing this you will actually be able to drop her weight just as fast while feeding the bird as not. The benifit of feeding is obvious as her body is staying much more healthy as she burns the food rather that shutting the body down to conserve energy.

I would like to hear you guys elaborate on the use of rich and not so rich food. I'm trying to make sure I understand this correctly. So you use rich foods to drop weight slowly, which increases metabolism. Does that mean, then, that small portions of rich food should be given throughout the day? What would be an example of this? Ice cream is rich, for instance. But as an example, if I tried to increase my metabolism by slowly bringing my weight down with a plan of rationing ice cream, I think it may turn out to be a REAL slow process... as in never ;D lol. I also understand crow and quail for intance, being rich foods, but what do we mean when we say "rich?" Rich in what? calories? Protien? Carbs? Fat? All of the above? Thanks for any replies in advance.

[Master Yarak]

Most people mean "rich" as in protein. It tends to be lean with little fat and high in muscle. It is processed quickly and tends not to be rib-sticking. Too much protein is not a good thing long term. I noticed the trailing edges curling up one year, I asked my vet he said too much protein. I was feeding a much higher portion of beef heart that year during the moult. I gave away lots of squirrels to my apprentice.
Yarak

[Bridget]

I had Storm (FPRT) flying sharp on the creance the day before her first hunt, came to the lure well, but the next day I took her hunting and she wouldnt respond to me. Just flew off after about 20 mins of flushing and there were soo many bunny tracks in the snow. >.< Tried brigning her back to the lure but nothing would work. Spent several weeks looking for her.

So my question: Is there a big difference between good creance-flying weight and hunting weight?

FG