EPOW - Ecology Picture of the Week

Southern Banded Groundling

Southern Banded Groundling (Brachythemis leucosticta), Family Libellulidae
top: female; bottom: male
Lake Baringo, Kenya

Explanation:  Here is a widespread and relatively common denizen of much of east and central Africa, the dragonfly known as the Southern Banded Groundling.  

Quite well-named, it is, occurring mostly south of the Sahara Desert region, being obviously banded, and having the habit of sitting on or just above the ground.  

But look at the two main photos, above.  The top photo is the female, brightly yellow banded, and the bottom photo is the male, more drably colored.  And the wings between the sexes differ drastically with different cells of the wings being colored or darkened.   And young males appear the same as females but darken and develop the wing spots as they age.  

Male Southern Banded Groundling.
   

Female Southern Banded Groundling.

  
It was recently discovered that this "most familiar dragonfly" of Africa actually consists of two species (Dijkstra and Matushkina 2009), the Southern and Northern Banded Groundlings, with some distributional overlap.  But the one presented here is the "original" Southern species, where I photographed it at Lake Baringo in southern Kenya along the East Africa Rift Valley.  

Southern Banded Groundlings (and their Northern cousin) are known to use large mammals, including people, to stir up insect prey as they move along.  They will sometimes actually follow you, as you shuffle along, searching for disturbed smaller insects they can snatch on the wing.  This is called "accompanying behavior" (Corbet and Miller 1991).  

Moreoever, this species, and others, of dragonfly can help serve as a bioindicator of toxins and pollutants (Weir 1974) and metallic elements (Lesch and Bouwman 2018) in the environment.  

This is a most interesting, varied, and useful species!  
  

         
Information:
    Corbet, P.S. and P.L. Miller.  1991.  ‘Accompanying’ behaviour as a means of prey acquisition by Brachythemis leucosticta (Burmeister) and other Anisoptera.  Odonatologica 20(1):29-36.
    Dijkstra, K.-D. B., and N. Matushkina.  2009.  Kindred spirits: “Brachythemis leucosticta”, Africa's most familiar dragonfly, consists of two species (Odonata: Libellulidae).  International Journal of Odonatology 12(2): https://doi.org/10.1080/13887890.2009.9748343.
    Lesch, V. and H. Bouwman.  2018.  Adult dragonflies are indicators of environmental metallic elements.  Chemosphere 209:654-665. https://doi.org/10.1016/j.chemosphere.2018.06.029.
    Weir, J.S.  1974.  Odonata collected in and near seasonal pools in Wankie National Park, Rhodesia, with notes on the physico-chemical environments in which nymphs were found.  Journal of the Entomological Society of Southern Africa 37(1): https://hdl.handle.net/10520/AJA00128789_2846.

Acknowledgment:  
    My sincere thanks to Dennis Paulson for identification of this species, and confirming some of its ecological behavior.