We tested whether habitat selection by adult dragonflies or differential survival of larval dragonflies, both in response to tree canopy cover, determines where dragonfly larvae are found. Research was conducted at Koffler Scientific Reserve (KSR). See French and McCauley (2018).
Canopy cover surrounding aquatic mesocosms limited the number of visits by adult dragonflies, but did not affect the survival of larval dragonflies. It is therefore likely that previously observed patterns of decreasing larval dragonfly diversity with increasing canopy cover (McCauley et al. 2008) are driven by the limited attraction of adults to closed habitats.
Aquatic mesocosms situated under artificial shading ("open" and "closed") at KSR. The white netting was removed before experiments. © Sarah K. French 2013.
We examined whether forests or forest edges imposed a barrier on the movement of adult dragonflies at small scales. Research was conducted at Koffler Scientific Reserve. See French and McCauley (2019).
When released at forest edges, more dragonflies flew towards fields than forests. However, there were species-specific responses to forests in terms of movement and flight times. Open environments such as fields therefore likely facilitate the movement of dragonflies at small and large scales, but forests may not be complete barriers for movement.
When released at a forest edge, Leucorrhinia intacta individuals (black abdomen and thorax) were less likely to take flight than a Sympetrum species (red abdomen and thorax). Across species, dragonflies flew more towards fields than forests when released at a forest edge © Sarah K. French 2019 and published online by John Wiley and Sons.
The influence of landscape matrix conditions on the recovery of larval dragonfly communities following a drought. In collaboration with researchers through the Edwin S. George Reserve.