Hearing the sound of the birds singing high in the treetops, Jim whistled back at them, smiling when they returned his call.
"Did you hear that, Spock?" Jim asked, enthused.
"I did, it was pleasant to hear," Spock replied, the corner of his mouth twitching upward as he looked at the smile on Jim's face.
"Try it, whistle at them," Jim encouraged, knowing the Spock had a fondness for birds.
"I have never whistled before," Spock admitted, raising his eyebrow.
"Go on, try."
Turning to face the treetops, Spock took a deep breath in and whistled, the birds singing back.