Blue Emperor (Anax imperator)

The above photograph by Corrie du Toit, can be seen in the OdonataMAP database here.

The Blue Emperor Anax imperator is a large species of hawker dragonfly of the family Aeshnidae.

Identification

Very large

Length up to 79mm; Wingspan attains 110mm.

Both sexes are distinctive and unmistakable in Southern Africa.

Anax imperator – Mabibi, iSimangaliso Wetland Park, KwaZulu-Natal
Photo by Ryan Tippett
Anax imperator – Near Hluhluwe, KwaZulu-Natal
Photo by Ryan Tippett

Habitat

The Blue Emperor inhabits a very wide range of habitat types and can be found virtually anywhere in South Africa. Anax imperator is a highly adaptable and successful species and will breed opportunistically at virtually any fresh water habitat, including cement reservoirs. It is most often seen near water and it has a preference for still habitats with plentiful water plants such as dams, ponds, marshes and pans. The Blue Emperor is also regularly encountered far from water, even in very arid regions like the karoo and the Kalahari. This species is able to quickly colonise seasonal wetlands after rain.

Habitat – Gamka River, near Calitzdorp, Western Cape
Photo by Ryan Tippett
Habitat – Umgeni River, KwaZulu-Natal
Photo by Alex Briggs

Behaviour

This species is a powerful and fast flyer and spends most of its time on the wing. At water males tend to pick a general flight path that they follow back and forth, deviating only to chase down prey or a rival male. Females are most often seen when they visit the water to lay their eggs, otherwise they are inconspicuous. When at rest all Anax species hang vertically. They may be active at dusk on humid evenings, and regularly join mixed species feeding swarms at this time.

Status and Conservation

The Blue Emperor is a common, adaptable and widespread species. It has a high resistance to habitat degradation and can occur at virtually any water body, man-made or natural, including stagnant and somewhat polluted waters. It is listed as of Least Concern in the IUCN Red List of Threatened Species.

Distribution

Anax imperator has a vast distribution and is found virtually throughout Africa. It also occurs throughout most of Europe and central Asia and south to parts of the Arabian peninsular and Southern India.

The map below shows the distribution of records for Anax imperator in the OdonataMAP database, as at January 2020.

Use this link to embed this map of distribution records in OdonataMAP: http://thebdi.org/wp-content/uploads/2020/01/664140-Blue-Emperor-actual-records.png

The map below is an imputed map, produced by an interpolation algorithm, which attempts to generate a full distribution map from the partial information in the map above. This map will be improved by the submission of records to the OdonataMAP section of the Virtual Museum. Use this link to embed the imputed distribution map: http://thebdi.org/wp-content/uploads/2020/01/664140-Blue-Emperor-inner-core-outer-core-and-periphery.png

The map below shows the imputed distribution which has been adjusted for terrain roughness

Blue Emperor record by Christian Fry
Dragonfly Atlas: Megan Loftie-Eaton, Sally Hofmeyr, Ryan Tippett & Les Underhill
Dragonfly Atlas: Megan Loftie-Eaton, Sally Hofmeyr, Ryan Tippett & Les Underhill
Megan Loftie-Eaton is our communications, social media and citizen science coordinator. Prior to her work for the BDI, she coordinated OdonataMAP, the Atlas of African Odonata. Sally Hofmeyr has many years' experience in the academic world, writing her own material and editing the work of others. Her academic background is in the natural sciences: her PhD and first postdoc in ornithology and environmental change (Animal Demography Unit, University of Cape Town). Ryan Tippett is an enthusiastic contributor to Citizen Science and has added many important and interesting records of fauna and flora. He has been a member of the VMU since 2014 and has currently submitted over 11000 records. He is also on the expert identification panel for the Odonata Map project. Prof Les Underhill has been Director of the Animal Demography Unit (ADU) at the University of Cape Town since it started in 1991. Although citizen science in biology is Les’s passion, his academic background is in mathematical statistics.