What are 2 unique characteristics shared by all birds? answer quickly!

Two unique characteristics shared by all birds would be:

1.  How they live, eat, and survive. This is a unique characteristic because, different kinds of birds eat and survive differently. Depending on the species and environment.

2. How they mate with each another. This is another unique characteristic because, every kind of bird species has a unique way to their mating rituals.

Hope I helped!

- Amber

Dna overload will occur