Then you go do something else that's relevant to your top-tier utility function.

You can contrive a situation where the lower tier matters, but it looks like someone holding a gun to your head, and threatening to kill you if you don't choose in the next 5 seconds whether or not they shoot the sparrow. That sort of thing generally doesn't happen.

And even then, if you have the ability to self-modify, the costs of maintaining a physical representation of the lower tier utility functions is greater than the marginal benefit of choosing to save the sparrow automatically because you lower tier utility function says so over choosing alphabetically.