Southern Riverking (Zygonoides fuelleborni)

Zygonoides fuelleborni is a species of dragonfly in the family Libellulidae.

The photo above (by Gary Brown) can be viewed in OdonataMAP here.

Identification

Medium-large to large size.

Length attains 56mm. The wingspan can reach 90mm.

Both sexes are similar in appearance. The most distinguishing feature of this species is the swollen basal segments on the abdomen. This is most noticeable in the male.

Most similar to Olpogastra lugubris but that species has a noticeably long and thin abdomen.

Zygonoides fuelleborni – Adult male
Mkuze River, KwaZulu-Natal
Photo by Ryan Tippett
Zygonoides fuelleborni – Adult female
Mkuze River, KwaZulu-Natal
Photo by Ryan Tippett

Habitat

The preferred habitats are large, strong-flowing savanna rivers with wooded or reed-lined banks. They especially like the faster sections of rivers (rapids, falls), often with exposed rocks or overhanging trees that can be used for perching.

Habitat – Mkuze River, KwaZulu-Natal
Photo by Ryan Tippett

Behaviour

Zygonoides fuelleborni is a busy, active species with a swift, powerful flight. Perches regularly between flights, but seldom for very long. Often perches on overhanging reeds, trees or bushes and frequently sits on rocks close to the water. Frequently joins mixed species hunting swarms at dusk.

Status and Conservation

The Southern Riverking is localised and thinly distributed in South Africa. It occurs primarily in undisturbed habitats, although it is often found near weirs and dams on rivers that create rapid-like conditions. It is listed as of Least Concern in the IUCN Red List of Threatened Species.

Distribution

Zygonoides fuelleborni is found in East and Southern Africa, from Kenya down to central KwaZulu-Natal in South Africa.

Below is a map showing the distribution of records in South Africa for the Southern Riverking. Taken from the OdonataMAP database as at February 2020.

The next 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.

Ultimately we will produce a series of maps for all the odonata species in the region. The current algorithm is a new algorithm. The objective is mainly to produce “smoothed” maps that could go into a field guide for odonata. This basic version of the algorithm (as mapped above) does not make use of “explanatory variables” (e.g. altitude, terrain roughness, presence of freshwater — we will be producing maps that take these variables into account soon). Currently, it only makes use of the OdonataMAP records for the species being mapped, as well as all the other records of all other species. The basic maps are “optimistic” and will generally show ranges to be larger than what they probably are.

These maps use the data in the OdonataMAP section of the Virtual Museum, and also the database assembled by the previous JRS funded project, which was led by Professor Michael Samways and Dr KD Dijkstra.

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.