I Missed My Tern

Saturday was World Migratory Bird Day
I am now surprised to learn
And among many many birds that fly the aerial highway
There’s none like the Arctic tern.

Whole flocks fly from Arctic to Antarctic and retern 
Ha! now, isn’t that a super cool pun to kill?
A round trip of 60,000 km (your tummy will churn)
Before they settle down with a beer to chill.

A mysterious silence descends before they leave home
Are they meditating on the flight ahead
Or checking Insta and reconfiguring 4G settings to Roam?
No clue.  But biologists call this behaviour ‘dread’.
ps.  I dread meditation too, it’s definitely a syndrome
So, am I a tern intern crossbred?  

Now, if you see a flock of this Migration’s Star Emblem  
And (because you studied engineering) your idioms are wrongly honed
Don’t rush to pick the nearest rock and fling it at them
Because, you’d read, one must never leave a tern unstoned.