Yesterday in my garden, there were several swallowtails about as usual. Occassionally, they chase each other, sometimes as part of the mating ritual. But one chased a house martin! It was only for a few seconds, or perhaps 20 yards, but nonetheless! I can't imagine it was fooled into thinking the martin was a swallowtail of the opposite sex. So perhaps it was chasing it away?
Also, the swallowtails in my garden are very keen on Crithmum maritimum (rock samphire) for laying eggs on. There are a few more standard umbellifers about, but I have not seen the swallowtails take much interest in them. We don't have much fennel (giant or otherwise) in the area.
