Keyhole Glider (Tramea basilaris)

The photo above (by Gerhard Diedericks) can be viewed in OdonataMAP here.

Find the Keyhole Glider in the FBIS database (Freshwater Biodiversity Information System) here.

Family Libellulidae

Tramea basilaris KEYHOLE GLIDER

Identification

Medium sized

Length up to 50mm; Wingspan attains 93mm.

Most resembles Tramea limbata (Ferruginous Glider). That species is similar in both size and shape but has narrower, darker markings at the base of the hind wings and a dark brown face. Tramea basilaris has a red face with a variable amount of yellow.

Click here for more details on identification.

Tramea basilaris – Male
Mpempe Pan, KwaZulu-Natal
Photo by Ryan Tippett

Habitat

Utilises a wide range of freshwater habitat types, but favours the still, ephemeral waters of pans, pools and marshes. Regularly found away from water especially in open, grassy areas with scattered bushes and trees.

Habitat – Mkuze Game Reserve, KwaZulu-Natal
Photo by Ryan Tippett

Behaviour

More often seen in flight than perched. Has a smooth, gliding flight as it patrols back and forth along an irregular route. Sometimes hovers for a few seconds before continuing on its way. Perches on top of bushes, trees and reeds. Often found singly but is likely to be gregarious at favourable sites. A highly nomadic species that moves about in response to rainfall.

On the wing from November to May.

Status and Conservation

Common but highly nomadic and erratic in occurence. May be abundant at certain sites. Listed as of Least Concern in the IUCN Red List of Threatened Species.

Distribution

Widespread throughout Sub-Saharan Africa. Liable to be encountered almost anywhere but most common in the savanna regions. It’s range extends beyond Africa into parts of the Middle East and Asia. Also occurs on Madagascar and many of the Indian Ocean Islands.

In South Africa it is mostly found in the north and East but vagrants can turn up anywhere.

Below is a map showing the distribution of records for Keyhole Glider 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.