The question you raise around extirpation is, I think, if we're uncertain that we can get things back, then is it reclamation? In some cases I think we have to accept that this is a transformed landscape that, as you said, may not be in its original shape but should be in a safe and functioning state.
This really highlights the need for planning in advance to avoid those areas where there simply isn't a substitute for certain habitats. We draw attention to woodland caribou because it's in sharp decline in many parts of the country, and because all the science I've seen—and Matt can speak to this with more authority—suggests that they simply do not repopulate disturbed land, whether it's forestry or oil sands land. In those cases, we have to be very careful about where we expand and how we expand, because some things are simply irreplaceable.
This calls for needing to step back a little and look strategically at the ecosystem's services and the habitat level values that are still there, now while we have a choice, and to make choices that are for the social good in the long term. While we may be able to re-engineer some elements of the landscape to a safe place, there are some for which we simply have to agree that we cannot and will not. If we choose to make that sacrifice, we should do so with all the information and all the public debate that goes along with it.
Again, I call for a broader view on the values, and some humility in knowing that some values will not be replaceable.