Re-bloom on once blooming bushes

Does anyone have any info on what actually triggers blooming on once blooming roses?

I have noticed that this past autumn here in Australia that many of the feral R.eglantine have re-bloomed. Also, my bush of Schrooners Nutkana ( I may have misspelled that ) gave a few blooms as well.

We did have major bush fires over summer with considerable smoke haze for some weeks.

Just to add to the confusion ( mine, that is ), when in the tropics, I put some bushes into a cold store for 4 weeks at 2 deg C, after which S. Nutkana did not bloom but others did, including Refulgence.

Is it a combination of factors that change with each variety, as I suspect?

I have heard that here in California in the US a few people had reblooms of Alba and Damask roses during a few years ago during El Nino weird weather season. Who knows why this happens, and it would be worthwhile studying.