Odd URL

I just noticed today on my site that the URL has an odd end on it. The site is http://www.stdavidparish.org. The home page URL displays fine, but when I click on any other sub-page, say for example, the History page, it appears in the address bar like this: http://stdavidparish.org/history/#.UuPPPmAo7IU Then the trailing item will change periodically.
The page appears fine if you manually enter it without the odd trailing item.
Could anyone tell me where this may have come from? Could it be a by-product of a plug-in perhaps? I do have the permalinks set to display the post-name. Thank you.