Ummm, have to say that sort of thing has crossed my mind. In 2006, walking towards Villamayor de Monjardin, I stopped for a break and just stood watching the birds high above me. After a few minutes of standing still, I realised they were circling me and getting closer and closer. What I took to be eagles were, in fact, vultures. A couple of hours later arriving pilgrims mentioned they had seen vultures devouring a dead sheep in much the same area I'd been in.
Food for thought there? Sorry, not a very good pun! But we do tend to forget that, while we think we are invincible and better than other creatures, we are just part of the food chain.
Trudy
EDIT: Perhaps I should point out that vultures only eat dead creatures, they are not going to pounce on unsuspecting pilgrims!