The Doctor's face lit up with delight. "Oh, I say, you are gorgeous! Hello down there. By all means, speak." He spread his hands.
"We greet you in the name of the Thrikeshaw, who were once all but wiped out in the nanobot wars of Jalopherum. In desperation, we reduced our essence to DNA and seeded ourselves here in an accelerated evolution pod. Thus we developed into these forms in just a few thousand years. We have survived - we were content."
As he spoke, Donna reflected that the voice sounded more like a cartoon character than anything else. It was hard to take seriously. Then again, a talking bird was probably one of the less weird things she'd seen in her time with the Doctor.
The Doctor stuck his hands in his coat pockets. "So what's the problem then?"
The leader stepped forward and craned his neck up. "The nanobots have found us."
River fixed the Doctor with a gaze. He gaped first at the birds, then at her.
"Nanobots, that's bad, right?" hissed Donna.
"Just a bit, yeah. Would have taken over the universe starting from Jalopherum if the Shadow Proclamation hadn't ordered a forcefield set up around that entire system."
The Doctor turned back to River. "How did you get here?"
"Vortex manipulator." She raised her wrist. "Easy peasy. But come on, it's not safe out here."
River turned and led the way into the dark forest. The crowd of birds picked their way after her as Donna watched, fascinated. Left, right, beak. Left, right, beak. Maybe they used to have three legs in their prior form.
The Doctor glanced at Donna and strode off after River. Donna huffed once under her breath and followed. Nothing but a torch, and she was pretty sure that wouldn't help against nanobots.
"You will be safe with us," a cartoony voice warbled from close by.
Donna yelped and thought she heard giggling. "Don't frighten me like that! I nearly died." She looked down at the speaker. "Uh...I'm Donna. Pleased to meet you." She knelt and extended a hand, then almost thought better of it. A bird can't shake hands. But the creature calmly laid its beak into her palm.
A sense of great history came over Donna, a sense of loss and survival against huge odds, and finally a sense of this particular creature's character. Female, fun-loving, single...single? She slipped her hand away. "You're telepathic!"
"Only by touch. My name is Karanga, the song of welcome."
"Donna!" The Doctor called from some distance ahead. "Don't get left behind!"
She and the bird followed along. "So...Karanga. The people around here think you are real birds?"
"Oh yes. Once they even hunted us for food, but now we are venerated as a national icon. Kiwi, they call us, for the sound we make. I'm afraid we haven't learned proper birdsong."
Donna peered down at her new friend. "Hang on...Kiwi. Isn't that a hairy brown fruit?"
"Well." Karanga laughed and fluttered her tiny wings, indicating her own plump hairy body. "What do you think they were named after?"
"How about that." Donna shook her head slightly and worked on catching up to the Doctor and River.