Western Tiger Swallowtail

Large yellow butterfly with black stripes. The wing span was about 100 mm. There are usually tails on the hindwing but this one had its tails bit off. There was an injury on its abdomen so I have a feeling that this one was near the end of its life. It flew from branch to branch, staying low. My daughter and I were able to right up to it and it didn't fly away.