While it is important to know your birds bottom weight - it's not a bad idea to know their top end as well.
I found out Tess' this weekend.
One of the beautiful things about harris hawks is that they have a large weight window in which they will fly. For instance, Gonzo will fly between 575 and 675. Not only will he fly - but he'll hunt. I've never tried to fly him higher, but at 675 I start to lose responsiveness. ( Read that as he don't come back as quick). I'm not afraid of losing him - but I like instant recall in my birds.
When I acquired Tess two years ago, I was told that her flight weight was around 800 grams. Seemed like a good place to start. I flew her most of the first season between 800 and 850. That weight has migrated higher and now she flies mostly between 940 - 960. She hunts hard and her response is great. The birds will both fly at slightly higher weights if they are hunting together. One will egg the other on, and as my catch per outing ratio tells me - I'm doing well at these weights.
But Saturday was different. Gonzo was way too high, so he stayed home. Tess was high - awww, but what the heck. It was cold, cold, cold. She hasn't been eating as much as I had rationed her food. She should be motivated.
She was at 1020. She followed, she chased - but she never really connected. There was a classic chase - the squirrel scampering across the ground, Tess hot on his tail. It should have been a gimme, but Tess aborted, pulled up early, and the squirrel went on.
At one point we found a spot where something had been hoarding what it must have thought were eggs, but I believe these eggs will be very hard to eat.
Later, we got a squirrel moving through the trees, it shot up, above the canopy. I could see Tess coming down from above. There was a tussle in the tops of the trees. I could hear the bells and see the branches rustling.
Tess raked off to a nearby tree.
We continued on Tess finally committing to a chase off in the distance. I chased her through the cane brake to find a squirrel racing down the side of a tree with Tess hot on his rear. The squirrel corkscrewed around behind the trunk and disappeared where the trunk met a large, partially frozen,vernal pool. The next thing I know, Tess is following something that is swimming across the water.
It was a nutria that had been hiding under the base of the tree.
She followed it intently, from
tree to tree through the swamp, me tagging along on the shore. It was like she was trying to figure out the best angle from which to grab the thing.
But it soon disappeared under a root ball.
It was time to call it a day. I'd found the weight at which Tess didn't chase with abandon - And she is still rationed until she gets lower. I also found a small bite on her toe - the bottom of her toe, beneath the talon. I don't think chaps would have stopped it, but that explains why she stopped the tussle in the tree tops.
It's good to know that she does have a high end.