Butterflies of Africa
Family - PIERIDAE
subfamily - COLIADINAE
Veronica Coetzer www.coetzernaturephotography.com
The Grass Yellows
are all fairly small butterflies, readily recognised by their bright
yellow wings and their habit of gathering in small groups on patches
of damp sand or soil. Despite their name, none of their caterpillars
feed on grasses - the name is derived from the fact that most
species are found in disturbed grassy habitats.
are among the most familiar of tropical butterflies.
There are 70
known species worldwide, of which 36 are found in the Neotropical
region, 13 in North America, 10 in Africa, 25 in the Oriental region
and 10 in Australia / Papua New Guinea. Many are migratory in
the ranges of several such as hecabe
overlap into in 2 or more of the zoogeographical regions.
is found across the entire African continent including Madagascar.
It also occurs in Arabia, the Indian subcontinent, south-east Asia,
Papua New Guinea and Australia.
This is a savannah and grassland species but it
sometimes enters forests during the dry season.
The larval foodplants
used in Africa include
Sesbania, Albizia, Tephrosia ( Fabaceae )
and Hypericum ( Clusiaceae ).
In other regions of the tropics Desmodium,
Pithecellobium ( Fabaceae ) and
Erioglossum ( Sapindaceae )
are also used.
often gather in huge numbers to imbibe mineralised moisture from damp
ground and there are many accounts in literature of migratory swarms
aggregating in this way. Larsen for example describes seeing
"riverbanks turned yellow by vast hordes of mud-puddling males".
The images here and
on the following page were taken by wildlife photographer Veronica
Coetzer who vividly recalls watching these butterflies at Chobe in
Botswana in March 2012:
"The highlight of
the trip was the extraordinary sighting of many thousands of tiny
yellow butterflies at Elephant Valley and the fascinating behaviour
of animals and birds towards them. White-crowned Lapwings and
Blacksmith Lapwings looked like they didn't really enjoy eating the
butterflies - they would first dip them into water before swallowing
them. A Little White Egret was in a feeding frenzy running
frantically around and in its typical way stalked its prey.
Strangely enough it ignored all the thousands of yellow butterflies
and only picked out brown coloured ones. What we enjoyed most were
the baboons! They ran through them, played between them, tried to
catch them and just sat and stared at this phenomenon. Elephants,
warthogs and kudu also ran through them and it was just such a
magical sight - this yellow confetti dancing all around them".
It could be
concluded from the above description that the yellow colouration of
Eurema species is aposematic and
intended as a warning towards birds and reptilian predators that the
butterflies are unpalatable or noxious.
more photos by Veronica Coetzer