I don't have an exact ethological answer as I'm not knowledgeable with hawk behaviour. But with some basic knowledge of physiology and tactical analysis I can give you a "common sense" answer.
Many avian species have the ability of synchronized flight. A result of a combination of evolutionary traits such as physical dexterity, acute vision, and fast neuron connections between the two.
Similar to two people dancing, many of the movements are practiced but often improvised. One person leads while the other reacts accordingly. But bird brains are much more specialized for the activity.
It takes practice (birds practice every day), and eventually "muscle memory" removes the need for conscious processing between eye and muscle. A direct connection between the two brain functions is created, making the movements of the two seem almost instantaneous. Human visual processing is not sufficiently fast enough to distinguish the extremely small delay between the two birds' movements.
As to why they do it, it is likely a social behaviour; a way of playing and a form of bonding between mating pairs. It could also have some practical function to improve hunting success. In pairs, chances of sighting a meal is doubled, tactics such as flanking and ambushing are made possible. Meanwhile, with synchronized flight the chances of detection and preemptive evasion by prey remains the same as if there were only one bird. This at the cost of sharing a meal, which is of no consequence if food is plenty, but if meals are scarce it's more beneficial to keep the family alive rather than spare one bird from hunger.
If you were looking for some philosophical or spiritual "meaning", I'm sorry to disappoint you. Those may be emotionally satisfying. But as with every "system" in the universe and even the existence of universe itself, this has a scientific explanation based in truth once you allow ascertainable facts to drive your conclusions rather than arbitrarily assigning mystical properties to things we don't immediately understand.
probably because they are just traveling in a group possibly they are all male and they are looking for mates
A docent from a desert museum advised me that when the current year's young birds have learned to fly, the parents (male AND Female) "introduce" their new young to the area's other families of hawks. So it's sort of like their version of an "ice cream social". I had seen a large group like that, all soaring on the updrafts, but not really hunting anything, or protecting anything from each other. They were "just socializing".
They are migrating:
http://www.enature.com/outdoors/hawkwatch/
It means you probably aren't looking at Red-tailed hawks.
Only in times of migration.
It is normal for Red Tail Hawks to flock during migration.
fly
The NC law regarding to Hawks, is clear: The Hawks are free to fly.
no owls do
Broad-winged hawks.
they fly
Pigs do not fly.
It can fly over 40 miles long.
Keaton means "Where Hawks Fly".
The soft wings.
it is a animal that has two legs and acan fly
Occasionally, you will see hawks flying in groups or "kettles". But not usually.