Cardinals are among the prettiest of north Texas birds - especially in the winter, when there's a paucity of outside color. To achieve their natural color, they need to eat plenty of nutritious seed.
Cardinals, however, have a problem. They can't turn their heads easily. Their natural "eating position" is head/neck straight, and food in front of them. They can adjust somewhat to a traditional perch, but it's not easy for them. They also have a little trouble perching securely, whereas most other birds can clamp tightly onto a feeder or other perch.
So if you want your yard to become a Cardinal hangout (in our yard we usually have at least 6 at a time) I recommend having seed feeders that respond to their physical differences. Like a tray feeder or hopper feeder (pictured) or any of several other feeder types available that doesn't discriminate.
What cutting down all dead trees means It means that lots of birds will go homeless and will face the full brunt of winter. “Cavity-nesters” are kinds of birds that roost and nest primarily in old holes in trees. Usually, the holes were made originally by a Woodpecker. Examples locally are Chickadees, Titmice, Bluebirds and Wrens. When dead and dying trees are totally removed (cut almost to the ground), it reduces the number of potential nesting sites…and eventually the number of birds.