Tropical Bluetail (Ischnura senegalensis)

View the above photo record (by Andrew & Heather Hodgson) in OdonataMAP here.

Find the Tropical Bluetail in the FBIS database (Freshwater Biodiversity Information System) here.

Family Coenagrionidae

Ischnura senegalensisTROPICAL BLUETAIL

Identification

Very small size

Length up to 31mm; Wingspan reaches 40mm.

A small, variable damselfly. Most easily mistaken for a Sprite (Pseudagrion) or Bluet (Africallagma; Azuragrion). The most diagnostic features of Ischnura senegalensis are the bicoloured pterostigmas, distinctively shaped blue marking on segments 8 and 9, and the dark metallic blue patch on segment 2. Note that the sides of the thorax may be green or sometimes blue.

Females are very variable. The side of the thorax is brown or greenish-brown in aged females. Mature females have green thorax sides and immature females show bright orange sides.

Click here for more details on identification.

Ischnura senegalensis – Male
Amatikulu Nature Reserve, KwaZulu-Natal
Photo by Ryan Tippett
Ischnura senegalensis – Immature Female
Near Hluhluwe, KwaZulu-Natal
Photo by Ryan Tippett

Habitat

Able to utilise virtually any still water habitat, from lakes and pans to dams, ponds and marshes. Also inhabits slow-flowing sections of rivers and streams. Occupies both perennial and temporary waterbodies. In addition Ischnura senegalensis is tolerant of high salinities and polluted waters. Normally sits amongst aquatic vegetation like sedge, Reeds, grasses, waterlilies etc. Frequently found on mats of floating algae.

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

Behaviour

Mature males sit close to the water on vegetation. Females are found in the same areas as the males. The immature are often found in long grass and rank growth further from the water.

Most active from September to April, but recorded throughout the year. See Phenology below.

Status and Conservation

Very common and widespread. It is listed as of Least Concern in the IUCN Red List of Threatened Species. Ischnura senegalensis is a very hardy and adaptable species. It is often the most common species in degraded or marginal habitats.

Distribution

Ischnura Senegalensis has a very wide distribution. It is found throughout most of Africa, Madagascar, the Middle East, Central, Southern and South East Asia, Indonesia and on to Papua New Guinea. It is also found in parts of China and Japan.

In South Africa it occurs throughout, including arid areas and provided there is suitable habitat.

Below is a map showing the distribution of records for Tropical Bluetail 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.

Phenology

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.