E-Fauna BC: Electronic Atlas of the Wildlife of British Columbia

Cordulia shurtleffii
American Emerald
Family: Corduliidae
Species account author: Robert Cannings.
Extracted from Introducing the Dragonflies of British Columbia and the Yukon (2002)

Photo of species

© Jeremy Gatten  Email the photographer   (Photo ID #16092)

E-Fauna BC Static Map
Distribution of Cordulia shurtleffii in British Columbia
Details about map content are available here.

Species Information


Description

The face is dark with brilliant green eyes. The thorax is metallic green-bronze and, unlike those of many Striped Emeralds, has no pale marks on the sides. The abdomen is black after segment 4 and the male’s is widest at segment 8. Male’s appendages are forked in views from below and the side. Female’s vulvar lamina shown in figure. Length: ♂ 45mm, ♀ 46mm.


Flight Period

B.C., early May to early September; Yukon, late May to early August.

Genus Description


Remarkably similar to their close relatives, Striped Emeralds (a much larger genus). There are only two species of Common Emeralds – ours and the Downy Emerald (Cordulia aenea) in Eurasia – but as the English genus name suggests, they are widespread and common.

Biology

Family Description

Medium-sized dragonflies most often seen around lakes, boggy streams and peatlands in the mountains or in the north. Of 16 species in our region, 13 have Northern or Beringian ranges. The eyes, often brilliant green, meet broadly on top of the head. The shape of the anal loop in the hindwing is distinctive. Adults seldom perch during feeding and males frequently hover when patrolling for mates; when resting, they normally hang vertically or obliquely from vegetation. In flight, a male frequently arches its abdomen, which is often narrower at the base and tip. Larvae are usually squat and rather hairy; they sprawl in the mud and detritus in the bottom of the waters where they live.
Field Notes

The most commonly seen emerald in our region. Flies early in the season, usually well before Striped Emeralds appear, but both genera fly together later in the summer. Males patrol energetically and aggressively around forest lakes and peatlands, chasing off males of their own and other species.

Distribution


Northern. Widespread in B.C. and the Yukon.

Status Information

Origin StatusProvincial StatusBC List
(Red Blue List)
COSEWIC
NativeS5YellowNot Listed
BC Ministry of Environment: BC Species and Ecosystems Explorer--the authoritative source for conservation information in British Columbia.

Additional Photo Sources

General References


Recommended citation: Author, Date. Page title. In Klinkenberg, Brian. (Editor) 2021. E-Fauna BC: Electronic Atlas of the Fauna of British Columbia [efauna.bc.ca]. Lab for Advanced Spatial Analysis, Department of Geography, University of British Columbia, Vancouver. [Accessed: 2022-05-19 11:00:44 AM]
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