Snapped a pic with iPhone as nest is about 9 feet off the ground and I cannot see in it without stepladder. The day before this, I took a photo and there was only one egg in the nest. The day I took this (4/25/17), there were two other eggs of the same color and markings nearby on the ground.
You mentioned you found some matching eggs on the ground below this nest. Brown-headed Cowbirds, a brood parasite, have eggs very similar to cardinals and will toss out the eggs of the cardinal and lay their own eggs in their nests for the cardinals to raise. You likely have some Brown-headed Cowbird and Cardinal eggs in this nest, but unfortunately, they’re hard to tell apart. Learn more at http://nestwatch.org/learn/general-bird-nest-info/brown-headed-cowbirds/
You mentioned you found some matching eggs on the ground below this nest. Brown-headed Cowbirds, a brood parasite, have eggs very similar to cardinals and will toss out the eggs of the cardinal and lay their own eggs in their nests for the cardinals to raise. You likely have some Brown-headed Cowbird and Cardinal eggs in this nest, but unfortunately, they’re hard to tell apart. Learn more at http://nestwatch.org/learn/general-bird-nest-info/brown-headed-cowbirds/