View the above photo record (by Gerhard Diedericks) in OdonataMAP here.
Find the Keyhole Glider in the FBIS database (Freshwater Biodiversity Information System) here.
Family Libellulidae
Tramea basilaris – KEYHOLE GLIDER
(Palisot de Beauvois, 1817)
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 of the Keyhole Glider.
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.
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
Tramea basilaris is 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.
Further Resources
Virtual Museum (OdonataMAP > Search VM > By Scientific or Common Name)
More common names: Loerswewer (Afrikaans)
Type Locality: Nigeria, no locality data available.
Recommended citation format: Loftie Eaton. M; Hofmeyr S; Tippett RM; Underhill L. Keyhole Glider Tramea basilaris. Biodiversity and Development Institute. Available online at http://thebdi.org/2020/05/12/keyhole-glider-tramea-basilaris/
