Like other hawkers they are strong flyers, and are frequently seen hawking for prey
well away from breeding sites. Woodland rides and clearings are often chosen as
feeding grounds, but A. grandis is equally likely to be seen over open parkland, heaths,
rough ground around mineral-extraction sites, or urban waste-ground and parks. At
breeding sites, males are territorial in the defence of their beats along water-margins.
Females lay their eggs singly, and unaccompanied by the males. For this purpose they
typically settle low down on the upright stem of an emergent plant such as Reed-mace,
the abdomen is curved round so that its tip touches the surface of the plant-stem, and
the eggs carefully placed, either just above the water-line, or below it (the female
gradually lowering herself until the lower part of her abdomen is submerged). The
nature of the perch or substrate for deposition of the eggs seems to be unimportant. Egg-
laying is frequently observed upon dead sticks, floating logs, or other debris, the key
requirement being, presumably, some solid support for the female which enables her to
lay eggs at around the water-line without becoming wholly immersed herself. Longfield
(1937) reported that females of A. grandis vibrate their wings whilst ovipositing, and this
has also been observed by D. S. Walker (pers. comm.), though I have frequently watched
ovipositing females which do not exhibit this behaviour. The flight period is very close
to that of Aeshna cyanea - from early July until the end of September.
Doubleday's (1871) Epping list gave it as common, it appeared on F. A. Walker's
(1897) Wanstead Park list, and Harwood claimed that 'probably it is acquainted with
every parish in the county'. It is mentioned in similar terms on subsequent lists, and
results of our current survey bear out the continued validity of Harwood's comment.
Since 1980 it has been recorded from forty-six 10 km. squares in Essex, including the
71