abandoned?

we have the cutest birdhouse hanging out back that sean got as a present

it's been hanging up for some time - like over a year
we've never seen birds in it
but i like to look in it anyway now and then and noticed something that looked like grass in it
sean was so excited
he decided we should clean it out so someone else could build a house in it
to our surprise this is what we found

so we put the house back together and have been watching for the mama bird
we're yet to see one
so we're thinking these were laid last year and abandoned
we're both so sad
there were 5 eggs in there
we have no idea what kind they are (if anyone knows please leave a comment)
we're going to keep on the lookout and check back in the fall
if they're still there in the fall we'll assume they were abandoned and clean out the little house
and hope we'll have someone make a house in it next spring
and not abandon them
we're also going to move it to a shady spot when we clean it out
i'll be sure and let you know