No onscreen deaths but a few are heavily implied.
Some scenes imply death via natural selection, but are quickly glazed over. One brief scene where a predator is holding a decapitated bird head, no blood is shown. Bright Bill's parents are presented dead by Rozz pulling up a limp wing, nothing more is shown than the single wing.
A puddle of green hydraulic fluid is shown on the ground after an anthropomorphic robot is injured. Another character asks the robot about it, the robot replies that she is fine. (The hydraulic fluid in this instance is treated like blood, even though it's green.)
A number of attack robots self-destruct in a forest and ignite, setting off a large fire that threaten many animals.
A goose injures its wing flying through a window. No gore is shown, it just flaps its injured wing awkwardly for the rest of the scene, and confirms that it can't fly.
A number of attack robots descent upon a greenhouse and start shooting lasers at a flock of geese that the audience has become familiar with. It's implied that many geese die, although there's no detail.
Many animal bones are shown in an eagle's nest. No gore, just bones, some recognizable as animals.
A number of "dead" robots and robot pieces are shown onscreen. One is reanimated, even if its half-rusted and barnacled state. Given that the audience has become familiar with these robot shapes, the scene can be thought of as a zombie scene.
The wild robot could be recommended to kids of any age who could handle the abovementioned violence.
There is moderate violence throughout the film.