Diversity of bird species and their potential ecological roles in
habitat maintenance on the wild coast of the Eastern Cape Province,
South Africa
Abstract
Birds provide important ecological services for the maintenance of
ecosystems’ integrity. However, there is limited research on ecological
roles of different bird species in maintenance of habitats in South
Africa yet many bird species are experiencing continuous conservation
threats. In this study, we aimed to document the diversity of bird
species in South Africa’s Wild Coast nature reserves, and to determine
potential role of each bird species in habitat maintenance using bird
feeding mode classifications as a species function’s proxy. Bird
observations were conducted afield over four years (2017 to 2020). Over
864 hours of field sampling in 2017-2020, we accumulated 818 bird
records containing 178 different bird species classified into 58
families. Shannon-Wiener Diversity Indices showed very high overall
species diversity, and across the nature reserves (H > 3.5)
with however, all nature reserves being non-significantly different. We
noted 32 bird species representing 30 families occurring across four
nature reserves with Silaka Nature Reserve having significantly more
diverse bird families than Mkhambathi Nature Reserve while not
significantly different to others. Forest bird species were more
dominant (42.1%; N = 178) throughout observations than other habitat
species. Annual bird species diversity across the observation years
remained very high (H > 3.5) with non-significant
differences across the years. However, the year 2018/2019, showed
significantly higher abundance of birds across all nature reserves.
Among different feeding modes, potential seed dispersers had a
significantly greater number of records than other groups while
pollinators were not significantly different in number compared to seed
predators. A non-significantly different number of birds in medium to
large size body size classes suggest availability of a variety of both
pollinators and subsequent seed dispersal vectors. Consistent with other
studies, conservation status and implications of bird species loss on
sustainable vegetation integrity must be prioritised.