Wednesday, July 5, 2017

concerning dispersal

Matthew comments on dispersal when the season is past its peak. I have noticed, both here and in Switzerland, that females may be seen flying decisively, at low altitude, and in a straight line, away from a wood. They are presumably seeking another wood in order to spread their progeny as far and wide as possible. We saw this again two days ago. In mid-Bucks there is a wonderful private estate within which there are 6 ancient woods, all within an area of 9 sq. km. Iris is found in all 6 woods, and, since the distances between neighbouring woods is not more than a few hundred metres, HIM will fly from wood to wood [although we would need to carry out marking and recapture to prove this.....tricky with HIM!].
In one of the high point territories, we watched 3 males engaged in aerial battles for 20 minutes; one of them, the largest, always prevailed and returned to patrolling his canopy between two ashes and an Oak.
We returned to our cars parked near a farmhouse several hundred yards from any of the woods when we saw a female fly past us at head level at a rate of knots, on her way to the wood we had left.

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