These two juvenile Great Northern Divers were in the bay by the sea-watching hide at the weekend during the northerly gales (and were part of a record-breaking 11+ I had on the day), and behaved in a way I've never seen or heard of before; maybe it's not so rare, and the photos are pretty crappy in the poor conditions, but worth posting as an aside.
The two birds were a considerable distance apart and began calling to each other - a high-pitched, eerie moan - before swimming directly towards each other, still calling frequently. They then circled each other closely a couple of times, and began bill touching - apparently non-aggressively - for a good ten seconds or more, which included gently gripping each other's bills, before circling each other closely again and swimming off side by side.
