Home Forums Hunting & Shooting Hunter's Campfire Falconry Friday! - it's all about the weight (pics)

"Weight management" is a buzzword (words?) in falconry, to the point that one gets really sick of hearing about it, but the reality is that weight is pretty much the whole ballgame.

One of the required pieces of equipment to get a falconry license in the first place is a quality scale (0.1gram resolution for smaller birds and 1.0gram resolution for bigger birds).

Most have more than one (I have three).

Here's the sitch -- there's a 3% difference between aggressive and couch potato and a 10% difference between aggressive and dead.

I know 10% seems like a nice cushion, but 10% of a 100gram Kestrel is 10 grams -- about the weight of a 3 day mouse "pinky".

And a 100 gram Kestrel will burn 15% BW per day -- at rest. At room temp.

So birds get weighed once a day, often twice a day , and falconers become adept at the alchemy of calories per gram of mice,rats,rabbits,starlings,quail, et al.

Sounds a little like reloading, no ?

Some examples:

When we were flying our Kestrel, her capture weight was 112 grams. That was the starting point. She'd give a good-faith effort at 112 but nothing special. At 115 grams she could care less. At 109 grams, she was on it. I flew her as low as 105 once, but that's really pushing the safety envelope.

So her total window was 6 grams and her ideal window was 3 grams. This with eating 20-25 grams of mouse per day.

The Harris Hawks came to us at 1070 grams (pig fat) and didn't start really paying attention until they hit 960 grams.
At 930-935 grams they're on it.

Now Harris' are notorious liars when it comes to food but they'll hunt over a much wider range of weights than any other bird.

If you tried to fly a 935g Red Tail or Gyr at 960 you'd be spending the night under the tree it flew up into waiting for it to get hungry enough to come down (and yes, this happens all the time. )

Yesterday, my girls started out at 965 - still huntable but I knew we were in for a long outing >>> at 935 they'll catch about 1 in 3 jacks, at 960 it's more like 1 in 10.

(In my defense, if there is one, I'd been feeding about 40 grams of wild jack but had switched to farm raised rabbit at 30 grams. It wasn't enough of a reduction in volume as farm rabbit is like switching your diet to Kobe beef after a month of venison).

Anyway, it did indeed take them 11 tries to catch one. Here we are having pushed nearly up to the snow-line. buggers!











fat & happy



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Very interesting Matt. Lots of details involved wow!

Excellent, informative post (a lot I did not know) and two beautiful Harris Hawks. Thanks.

I don't exactly know why, but I always look forward to the falconry posts on here. Fascinating information, and the pictures are fantastic.

Thanks for posting.

Kurt

Great info and pix, Matt!

Huh, I never knew about the weight aspect as it related to hunting. Ver cool!

This is great stuff! Love the details. Thanks for posting.

RS

Great info, I've been around a couple of falconers in the past, but did not realize the amount of effort involved in keeping them healthy.

These are always so cool.

as long as you're weighing the birds at least once a day (twice a day is pretty much mandatory for birds under 400 grams) you can adjust.

many things can throw you off:

exercise intensity (this one should be pretty obvious)

weather - seems obvious but a bird's metabolic rate is so high that a 30* drop in temps might triple their energy requirements

caloric density of the food (switching both lean-to-rich and rich-to-lean can initially cause a sharp drop in weight)


I've had periods where daily feeding varied from 20-80 grams per bird just to maintain current weight.

Thanks for the interesting info and updates. I really look forward to your posts each week. Keep them coming.

same here.....always fun to learn new stuff, one of the things i look forward to here every week now is this post....

Me too!

Nice. I like how they "fan" over their kill! I saw an article on a deer being taken down by an eagle in Russia. I recall that Golden Eagles were used to protect sheep and could take down wolves? Awesome none the less.

it's called "mantling" and is supposedly to hide food from overhead predators.

Mongolians hunt wolves with eagles - but those wolves are somewhat smaller than our Timberwolves, IIRC in the 60-70 # range.

I guess the take-away of that is to not turn the birds into Democrats!

Interesting stuff!

I know next to nothing about falconry, so this was a very interesting and informative post- reminds me of why I joined The Campfire . What is the range of Harris hawks in the US ? I live in S. Ind and had never heard of them before .

Those birds are cooler than cool! Please keep posting on them.

So if I understand you correctly these birds must have a very high mortality rate in the wild with stats like that?

they're primarily a Sonoran desert breed (think Mexico and Central America) but do range into southern Texas, Arizona, and New Mexico.

they have very long legs (heat dissipation) and very little down.

they're prone to frostbite if night time temps get below about 25* (30* for males) and we bring them in under 30* at night.

here are a few more pics of them if you haven't been following along: