[Tweeters] Doves?

[jimbetz at jimbetz.com]

Hi to the Doveaholics,

   So for the past month (at least) there have been two doves that visit
our backyard at least every morning and evening.  Always one Mourning
Dove and one European Collard Dove.  I'm getting the impression that
these two birds are "keeping company" (hanging out with each other).
And that they are "local" - there are here every day at the same time
of day and seem to arrive and depart together (at the same time).

   Do doves do this (hang out together)?  Even across species?  Is it
common?  Do they interbreed - and if so what is the result?
                                                               - Jim