Why are there multiple Parishes listed for Births & Baptisms in Scotlands People? When searching ScotlandsPeople it sometimes seems to list two parishes together. For example: * Urquhart and Glenmoriston * Old or West Kilpatrick * Ardnamurchan and Strontian or Sunart Why would this be?

There are several different reasons.

For the first example, Urquhart and Glenmoriston, that is the name of the parish, it consists of two places that were previously separate parishes but later combined into one.

Old or West Kilpatrick are two alternate names for the same parish. Apparently the West or Wester name was only used for a while in the 1600's, after a split with the east (new) side of Kilpatrick.

Strontian or Sunart are again two alternative names for the same place (the village of Strontian is in the Sunart area). These were previously part of Ardnamurchan and in an area of very low population so Scotlands People still combines them.

There are good lists of Scottish parishes at Scots Family and (varying levels of detail) Wikipedia.