Due to this obsession displayed about something immaterial, I have looked at sundry images, and quite frankly there are several that have similarities. Birds whilst being the same family do not look exactly the same.. Look at your chickens.
I do wonder why there is this obsession with trying to dictate what is happening in MY country. These birds what ever they are called are breeding pairs, and they circle and gyrate all year round. They LIVE HERE. They are not as per one of your links about broad winged something or other part of a flock.
And no I am not proud of killing them, that is your perception of what I should be feeling. You seem to be very good at putting your take on things. Maybe you should try asking rather than thinking.
I had stated previously I respect them, and admire them, and wish them well when they are catching lizards, mice, rats, other peoples chickens. But I am not going to stand by like a loon and gaze admiringly while they eat at my expense. Every chick, small bird taken is revenue lost.
Were I aware of them being endangered I would perhaps create or buy a sonic device to avoid killing them. As per the link I have provided a couple of times, there is only ONE endangered species, it is the National Bird, and it's demise as far as I can see is being brought about by the stupidity of the Government. Who are allowing development in the one area it lives, saying there is a special place being created for them as part of the project... So you disrupt their habitat, and make a special place for a creature that has run away and died.
As it is it is, stock protection is part of Farm husbandry. You kill Chickens, you kill livestock for food, you kill foxes, Coyotes, and sundry other critters that predate, maybe there is a coyote foundation out there ready to challenge their demise, because they are furry.
Finally, I see them fairly frequently, you may not be able to tell from the picture, but all of them are around the same size, and as they tend to gyrate in pairs they are NOT immature anything, and I repeat not part of a migratory flock.