Fact : #7

                                                                       Birds

• There are close to 10.000 different species of birds.

• All birds are warm-blooded vertebrate animals.

• Birds are endothermic, meaning their body temperature stays the same no matter what the temperature is outside.

• Birds bones are hollow and their vertebrae are fused together for strength. 

• Flying requires a good supply of oxygen, so it makes sense that birds have extremely efficient respiratory systems.

• A system of air sacs helps to insure that the lungs receive a constant supply of fresh air.

• Birds beat their wings when they take off to get thrust and lift.

• The color of the bird's feathers will often tell you whether it'd male or female.

• Females have more muted tones that provide camouflage so they can protect their eggs.

         Notes taken from : BrainPOP.com