I'd like to suggest the potential to add a new encounter, the Blue Quail. More specifically, Synoicus/Coturnix adansonii.

From what I gather, this bird tends to habituate grassy areas with ample seclusion opportunities, and doesn't like to come out into the open.
There seems to be enough coverage provided between the Savannah and Shrublands, and so it'd be a viable low-level encounter. If your king happens upon a scrape, the bird might be flushed out momentarily. In the case she were brooding, perhaps it might even feel threatened or protective of her eggs.
This could provide an option to either attack in return, scavenge for eggs, or leave the quail be. If we wanted to shake things up a bit, attacking directly might not be an option, but scavenging could definitely provoke the bird to attack you if you fail to snatch up any eggs. The Bird Eggs item already exists, so that's simple enough to find. This may or may not affect karma if successful.
To keep things interesting, this quail might even decide to become a little more frequent during the rainy season, since that appears to have an effect on migratory habits.

As far as I know, there are all of two bird-related battle encounters outside of events, one if your king is under level 16. This would provide an additional chance in the two lowest-level areas.