Common Thorntail (Ceratogomphus pictus)

View the above photo record (by Chris Willis) in OdonataMAP here.

Find the Common Thorntail in the FBIS database (Freshwater Biodiversity Information System) here.

Family Gomphidae

Ceratogomphus pictus COMMON THORNTAIL

Identification

Medium-large size

Length up to 53mm; Wingspan attains 69mm.

The sexes are similar but females are more robust and have broader abdomens with smaller foliations.

Most similar to Ceratogomphus triceraticus, but is smaller and paler. Ceratogomphus pictus has thin black edging on the abdomen foliations, compared to the thick black border found on Ceratogomphus triceraticus. In addition C. pictus has a small, thin, forward projecting spine at the top of segment ten. In C. triceraticus this spine is broad.

Click here for more details on identification of the Common Thorntail.

Ceratogomphus pictus – Male
Mkuze River, KwaZulu-Natal
Photo by Ryan Tippett
Inset by Gregg Darling

Habitat

Inhabits both still and running water habitats, including streams, rivers and dams. It prefers open and exposed areas with bare ground and rocks.

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

Behaviour

Often perches on bare ground or on rocks close to the water. Sometimes sits on low twigs or bushes near the water. Hunts from a perch and has a fast, powerful flight.

Status and Conservation

Common and widespread. Listed as of Least Concern in the IUCN Red List of Threatened Species. Readily utilises man made habitats like farm dams and is often present at eroded or overgrazed margins of water-bodies.

Distribution

Ceratogomphus pictus is a Southern African species extending from South Africa up through Namibia, Botswana and Zimbabwe to Southern Zambia. It is widespread in South Africa but is mostly absent from the humid lowveld and coastal parts of NE KwaZulu-Natal. It is also absent from most of the Karoo but is present along the middle Orange River.

Below is a map showing the distribution of records for Common Thorntail in 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.