Habitat characteristics and odonate communities at selected sites used by Mortonagrion hirosei Asahina (Zygoptera: Coenagrionidae) in Hong Kong

Abstract

Mortonagrion hirosei, a Near Threatened species, is a small damselfly recorded from several isolated sites across its entire range in eastern Asia. Previous research has indicated a strong affinity for brackish wetlands, including reedbeds and marshes, where potential predation or competition by other odonates is reduced. Results from surveys conducted in Hong Kong during 2009-2011 provide information on the habitat at a number of sites occupied by M. hirosei and report on the presence of populations in mangrove and mangrove-mosaic habitats as well as brackish marsh, often in association with a diversity of other odonates. Information is also provided on two previously unreported sites in Hong Kong. These new findings indicate that the species uses a greater diversity of habitats than the odonate-poor Phragmites reedbeds in which it has been well-studied in Japan, and consequently may be more widespread than previously supposed. Given that coastal habitats are threatened throughout its range, it is hoped this broader understanding of the species’ habitat requirements will encourage others to explore other coastal sites and to aid in its conservation.