Tell Me Why?

So today at work, I was working on the budget.  
 
Very intense, spreadsheet-to-spreadsheet work, checking numbers, converting currency, and by 2 pm my eyes were crossed and red. 

I took a step outside to look into the distance. 

Truth be told, I took a step outside to see if there had been a plane crash.   

The Runway is about 400 yards away and runs parallel to my office.  I am always aware of planes taking off and landing and you are used to the noise and it melts into the background.

Today, this one started rev'ing - about 200 yards behind me.... rev'ed and rev'ed, and then started to rumble down the runway.  Just as it drew level with me, the noise cut out, and the wheels screeched.

There was a silence over the office, and gradually we all stood up and looked over.   I think the moment's silence was us waiting for the explosion.   Thank heavens it never came. And suddenly the plane roared into life again shot off down the runway and took off ... still didn't sound particularly good, but it got off and was well away from me within minutes.

I stood for a moment and examined the ground for chestnuts... I've got three now.   But Some squirrel has been pigging out big time..  As I stood, I heard a noise and I looked up and a little kestrel was above me, hovering. So I ran in and grabbed my camera. 

I snapped away wildly for a while trying to capture its colour (impossible against the sky), and then suddenly a massive screech, and a heron flew up from the bushes and rushed at it. 

There then followed quite the air battle.  I was mesmerized. 

Kestral outflew the heron - but tell me this.  Why does the heron look like I've copied and pasted a cartoon one?