I have a friend who interpreted the two predator birds as two signs:
He said that the crow represents scavengers that eat the bodies of the dead; that eat the bodies of dead people if they're lying out in the open air, exposed to the elements.
He said the seagull represents a WORLDWIDE effect and by extension, the universality of the Church, because seagulls are found in every nation of the world, and their domain is ubiquitous, as is that of truth.
Furthermore, he said that there may be a mistake, that the 'crow' was actually not a crow, but a raven, and ravens are larger birds, scavengers as well, but their numbers have been greatly on the INCREASE in recent years. He has observed raven populations to have grown three times in just the last two years. He thinks this is God's way of preparing for the widespread deaths that are soon to come when bodies of people will be left lying outdoors exposed, and the scavenger animals will devour them.
St. Ignatius of Antioch, one of the glorious Martyrs of the Church, whose name appears in the Canon of the Mass, in the Great Invocation, a.k.a. Hanc igitur, was eaten ALIVE by ravenous lions.