What to do if nastersions go yellow?

What is a screech owls predators? What is spotting like? Is a mudlark a magpie or a sparrow or a skylark? How long can a nesting bald eagle go without food? Is an osprey a kind of hawk? How much do dodo birds cost? You live in SW Connecticut and saw 2 large birds with black feathers and red crowns and heads They looked like somewhat like vultures They perched on a large rock for a while Any idea what they are? Where can you get a lisence to keep a pet hummingbird? What sound do parrots make? How much do Pineapple green cheek conures cost? Do hummingbirds mate like other species? Will a handreared cockatiel get on with a handreared green cheeked conure? Is the roadrunner an omnivore or carnivore? Who harms or eats a condor? How far away can you hear a turkey gobble? Is a kakapo a Carnivore? WHAT does a swallow nest look like? In my backyard I have these birds nesting and when I go near they attack They have a yellow beak they are black capped they have a grey body and are white breasted Can any one tell me what they are? Does feather rhymes with father? Who invented the first birdhouse?