Natural RTOW
 

Just watched a crow come into our garden where we had put some stale bread rolls. The 'early bird' (sorry) crow landed on our table and picked the biggest piece of bread. Compared to the AUW of the crow - it must have been a significant weight (notwithstanding that it had just rained so "contamination" was involved). Anyway, when the crow eventually organised the load, it got airborne and (just) made it over our fence , flew downwards along our sloping field, and eventually gained some altitude and flew away. As a human ex 744 operator, I was impressed that birds can do all those calcs without a computer anywhere.
I know - it could have dropped the bread but you know what - it didn't.
Well done Mr Crow without Perf "A".:ok:

Then there is the matter of African Swallows carrying coconuts...

Reminds me of a scene I witnessed at a food court in Siglap, Singapore, some years ago. A crow swooped down and helped itself to most of the contents of a momentarily unguarded bowl of noodles and struggled to make it to a tree on the opposite side of the road! Many shouts of protest and abuse from the previous owner but to no avail.

The calculations are done through a super computer known as instincts, which in the air even the best human does not possess. But therein lies his greatness. Even without the instinc he flies where no bird can.

There was a time when man started out flying small planes in difficult conditions "possibly" above max AUW in hot/high conditions and jerked the aircraft in the air, nursing it to stay airborne by feel, keeping it over the fine line of being airborne or stalling. Alternatively they felt that it didn't feel quite right on takeoff then they closed the throttles and made another plan which contributed to his survival.
Perhaps that instinct of a bird was developed. It sure ain't developing in today's rule based/procedures written to the lowest common denominator airline world.

*by man/his I mean all of humanity who have taken the reins of a aircraft and demonstrated the above mention skill. For those of you who still don't get it, I mean woman as well.

*by possibly I'm not saying I did it, but I'm not saying it never happened. However that's not the point of the post.

The birds have to learn by making mistakes, just like humans. I was watching some blue jays come in to land at a raised platform feeder in our back yard one day, with a 25 kt wind. The platform had a raised edge that they landed on. They came from a tree which was upwind.

The adult birds knew all about landing into wind. They would leave the tree, fly past the feeder, turn 180 degrees, and land into wind. One juvenile jay decided the 180 degree turn wasn't necessary, and landed downwind. The ground speed at touch down was excessive, and he collapsed forward, doing a belly flop onto the platform - no apparent injury. The other jays seemed most amused.

Where I live there is a football field with tall arc lights. These poles are about 45 metres high.

Saw a magpie streaking at 12 inches above the field using ground effect and at amazingly high speed heading towards the base of one of the arc light poles. Then it simply pulled up with wings outstretched but not flapping and with perfect energy control arrived with landing gear extended at zero airspeed on the arm of the arc light. Beautiful to watch and the perfect climbing forced landing.