greater  Zandvlei  Estuary  Nature  Reserve

Displacement of Cape Spurfowl by Helmeted Guineafowl at Zandvlei Nature Reserve.
(this is an abstract from the paper presented at the annual Fynbos Forum 2010)

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Compiled by: Cassandra Sheasby   Cassandra.Sheasby@capetown.gov.za

photograph supplied by Cassy Sheasby

Cassy delivering her paper at the Fynbos Forum 2010.

From 2003 to 2005 ad hoc removal of Numida meleagris (Helmeted Guineafowl) was undertaken at Zandvlei Nature Reserve, Cape Town. From 2006 to 2009 intense removal efforts were undertaken and weekly bird counts from 2003 to 2009 were statistically analyzed to determine whether the removal of Numida meleagris had an effect on the population of Pternistis capensis (Cape Spurfowl).

In order to establish which resources these two species could compete for, a comparison matrix was compiled indicating possible competition for food, shelter and breeding habitat. A total of 334 bird counts were analyzed. From 2003 to 2005 a mean of between 6 and 9 birds showed an increase in the Numida meleagris population with a low mean increase of between 4 and 4.9 Pternisitis capensis per count for the same period. In 2006 to 2009 (intense removal period), the Numida meleagris population showed a strong decrease in mean from 6 to 2.5 birds per count and Pternistis capensis showed a strong mean increase of between 5.5 and 11.5 birds per count.

Annual means for the entire period show a strong inversely proportional relationship between the two species indicating the alien Numida meleagris could have a long term negative effect on the populations of Pternistis capensis in the Western Cape.