All three of the major search engines bid to become the default on iOS devices, but as most of you will know, Google is the default option on the iPad and iPhone. It has now become apparent that 2/3rds of all mobile searches actually come from iOS devices.
The information comes from Susan Creighton who testified under oath that all three of the networks bid to be default and that Google has been chosen (as it has for a few years). Apple [AAPL] does get some revenue from this deal.
Although Android has made a large dent in the mobile traffic on the web, it seems that iOS still is in the lead in terms of how many mobile searches are done from iOS based devices. Remember that millions of iPads have been sold in the last 18 months which will also account for a good portion of that.