Wildlife on passage from Borneo to Belitung

What mixed weather we are having on this passage. We have been sailing and/or motoring 3 days and two nights now. As I write this we are motoring on a relatively calm sea along the northern coast of Belitung which looks to be quite mountainous. This afternoon we had a sudden local front come through with squalls of up to 27 knots catching us unprepared under full sail. That was some fun sailing! Half an hour before we had lunch on a mirror-like sea with not a breath of wind. We've had one early morning of rain preceded by good sailing wind through the afternoon and night.
I have seen a variety of wildlife: quite a large pod of dolphins a little way off the boat - they don't come close here to accompany the boats as they do in the Pacific - are they a different breed or have they learnt to be wary of nets? Large schools of fish jumping out of the water - Tuna we thought, accompanying them were white Terns. We passed though an enormous area of blue saucer-sized jelly-fish and watched flying fish skimming across the water - mostly at night. Land birds get attracted to the masts and rigging. One evening as we sat having dinner just before nightfall a little swallow turned up and flew inside the cockpit, landing on Catherine's head - he then re circled and took up a perch on the railing, where he stayed for most of the night. We were about 15 nm from land at that stage. Then at about 5 am in heavy rain a whole group of swallows kept circling the boat shrieking loudly. They followed us for about an hour. Today, within sight of land, we had a small group of sparrow like birds circling and perching on the mast.