Can spanish moss kill a oak tree?

Spanish moss itself does not kill oak trees; it is an epiphyte that merely grows on them for support. It does not derive nutrients from the tree and doesn't harm the tree's health directly. However, if the tree is already stressed or weakened by other factors, the additional weight and shade from heavy Spanish moss growth could potentially contribute to its decline. Overall, healthy oak trees can coexist with Spanish moss without any significant adverse effects.