> 1. Why focus on Swifts as opposed to any other species in decline? They state that they are "iconic", so maybe that's the answer? Are they more "iconic" than any other specifies in Scotland?
They are a red-listed species whose population in the UK has declined by two thirds in 30 years. They are also a species for which there's an obvious measure that can be taken to reverse one of the changes which we know has happened over that time (improved building standards reducing the availability of nesting spaces).
If we can't take simple steps to protect swifts I don't think there's much chance that we'll protect anything. Conservation wise, this is really low hanging fruit.
> 2. Why are these bricks the best solution? Why not take that money that would be spent on bricks and instead preserve land, or just build them dedicated houses elsewhere?
Swifts are extremely site-loyal. You can't just hope that they will move elsewhere. Before buildings they nested in caves and tree cavities. Caves in particular don't move from year to year, so as a result the birds have a strong preference to return to the exact same location where they themselves were born and are slow to colonize other places.
Also your suggestions sound extremely expensive compared to this plan. Swift bricks cost like 30GBP retail. Yes, that's a lot more than the normal house brick they replace, but it's trivial compared to the other costs of building a house.
> 3. Why does this need to be done via government mandate versus voluntarily asking people to build Swift housing in existing buildings or land?
That's more or less the current situation in England, and perhaps unsurprisingly it's extremely rare for developers to actually install swift bricks. Indeed it's relatively uncommon for developers to actually follow through on their existing legally mandated ecological commitments [1].
Making something mandatory everywhere is also cheaper than making it only required in certain places: it eliminates all the bureaucracy around deciding whether this or that development is in the right area, and makes it extremely easy to follow and enforce the rules.
Now it is possible that the lack of nest sites isn't the dominant factor in the decline of swifts. For example it could also be related to the decline in flying insects, or changing weather patterns induced by climate change. We aren't really sure [2], however from that study: "it would be precautionary for conservation efforts to continue to focus on ensuring that safe and productive nesting sites are in sufficient supply", and we also know that the swift bricks will be used by many other bird species as well as swifts.
[1] https://wildjustice.org.uk/lost-nature-report/
[2] https://www.bto.org/our-work/science/publications/papers/dem...