As quick as his name was called, Natus started moving. Stabbing something as large as a roc with a dagger would likely only annoy it. As he was still moving he pulled a flask of oil from a compartment in his clothes and marked with a red line. He threw it at the downed rock and had it literally explode covering a small patch of his body in the sticky, flammable substance. He took out a match and struck it tossing it on to oiled creature causing a patch of his feathers to ignite. 

He then paused, and returned to a ready stance with a second flask of oil ready. He hoped that he would not need to use more of the limited resource, however the more time they wasted fighting the birds, the more time that another threat could attack them.