| habitat | the specific environment where an animal lives |
| reptile | ectothermic vertebrate that has lungs and scaly skin |
| urine | liquid waste that is produced in kidneys |
| bird | an endothermic vertebrate with feathers and a four-chambered heart |
| contour feathers | large feathers that give shape to a bird's body and help with flying |
| down feathers | feathers that trap heat a keep a bird warm |
| insulator | material that helps to keep something warm |