Yes. I have rss feedburner, it has a feature that can track who your subscribers are.( their email address) I don't know with other rss
Feedburner is widely regarded as the best way to track subscribers, though figures do fluctuate from time to time. Bear in mind that the figure that is shown is the number of people who viewed the feed through their newsreader the day before, which is why it goes up and down day to day.