The scope of North America's invasive species problem is enormous. For many folks in urban areas, it's possible that you might go your whole day only encountering one native bird species (American Crow), but a whole host of invasive species (Rock Pigeon, House Sparrows, European Starlings).
History shows that early, active intervention can pay enormous dividends. For example, Alberta remains the only area in North America without non-native rats due to a major interventions: https://www.alberta.ca/history-of-rat-control-in-alberta.asp...