Plumage & Buzzard question

Just a quick post from the Llyn Peninsular. I remember asking Andy C last year how to separate M&F Nuthatches and he mentioned that the male bird had a much more rich colour to it and this would be obvious when seen as M&F together. Having now got a pair regularly feeding from the nut feeder right outside my office window. The difference is glaringly obvious with the male having a much richer orangish/brown colour to his flanks and being generally much richer in colour overall. Once one has seen the differences its glaringly obvious, but not so easy just by looking at ID guides....thanks to the Tall Man. One other aspect of Nuthatch behaviour that has changed in the last couple of weeks is that they no longer spend most of the day near the feeders grabbing as much food as possible and then stashing it all around the area in tree bark and ground. The behaviour has now changed to feeding maybe four or five times a day with food eaten from the feeders direct and no longer stored. Both birds feed together but always on adjacent feeders. Despite being a pair they obviously still keep some of the typical Nuthatch behaviour and will not tolerate any other bird on the feeder, even their mate.

As I sit working at the computer I can watch the coming and goings at the feeding station and have noticed that the more "advanced" the breeding plumage of the males of various Greenfinches and Chaffinches that the more dominant or more aggressive they are towards other males. I assume these are not just the older birds but the more dominant in the flock pecking order who tend to come into breeding plumage earlier. Many of the males who have not yet reached full colour are less likely to be aggressive towards other whilst feeding but the more advanced males will not tolerate any other males anywhere near them and spend more time chasing off other males than feeding ! By far the most aggressive species on the feeders (after the Nuthatches) is Goldfinch. Whenever I hear a squabble start up outside I know at once the Goldfinches have arrived to feed.

A final question; I have noticed in recent weeks that Buzzards are around again in groups of anything of up to 7 birds at a time. Most of the winter the birds have been seen as singletons but have now obviously grouped back up again. I would have thought I would have seen pairs together now readying for breeding but its seems they have mixed in larger groups which do not seem to be in conflict/competition. Are these groups likely to be family groups from last years breeding or do Buzzards display in groups before pairing ?