Omission deeds are infinite - such as failing to save all sapient species/individuals.
As such, saving all of them cannot be, realistically, an obligatory requirement for one's morals.
But saving the ones you can save is morally salutary.
And saving the ones you can easily/relatively easily save (with little risk to yourself, with relatively little resource expenditure) IS morally obligatory.
Also - in detemining such actions, you must consider the individuals/species that exist NOW, not that may or may not exist in some ambiguous future.
And yes, sapience is the criterion - or, at least, one of the main criteria - for choosing whom to save. As Belz said, Sentient beings > non-sentient beigns.
As such, saving all of them cannot be, realistically, an obligatory requirement for one's morals.
But saving the ones you can save is morally salutary.
And saving the ones you can easily/relatively easily save (with little risk to yourself, with relatively little resource expenditure) IS morally obligatory.
Also - in detemining such actions, you must consider the individuals/species that exist NOW, not that may or may not exist in some ambiguous future.
And yes, sapience is the criterion - or, at least, one of the main criteria - for choosing whom to save. As Belz said, Sentient beings > non-sentient beigns.