Why do scavenger birds come after the great battle in the Middle East?

Les explains that the passage is not speaking of birds in the throne room but of the fowls that fly in the midst of heaven, the birds in the air around us. These are vultures and scavenger birds, and the pronoun refers to them. They are told to gather to the supper of the great God so they can eat the flesh of kings, captains, mighty men, horses, those who sit on them, and all men, both free and bond, both small and great. This great conflagration will fall upon assembled armies, especially in the Middle East. The birds of prey and scavengers come and sort of have a cleansing effect, getting the earth ready for the soon appearance of the kingdom. Les notes that all the Old Testament speaks of this event, when scavenger birds actually feast on these gathered armies, which is why it is called the supper of the great God. He also mentions, with caution, reports that a major Middle Eastern scavenger bird normally laid only two eggs and had one brood, then allegedly doubled to four eggs; he takes such reports with a grain of salt but later read it is more or less documented that this specific scavenger bird is multiplying at almost double normal in the Middle East.