You start from a fairly ill-informed depiction of early European settlement.

There was no indiscriminate or intentional 'slaughter' as you put it by all accounts, but rather, an intention of co-existence. Problems arose at some settlements because the original peoples had no concept at all of ownership. So, what happened, was where Europeans farmed and produced, somE could not conceive the animals and produce were not there for the taking, so they would regularly just take the domesticated farm animals (bare in mind they were considered crucial by the settlers for their survival and prosperity) and so settlers were forced to defend or shoot to save their own skins.

This is more or less how any deaths came. The growing distrust and actions did not help, but it was not a case that there was indiscriminate or random slaughter.