Master's and Doctoral scholarships in African Ecology: the role of
birds in shaping networks of interactions between plants, arthropods and fungi.
What will the World be like without birds? We know that birds
pollinate many plant species, they disperse the seeds of an even
greater number, in addition they are predators that prey on
innumerable insects every day. Nevertheless, the world without birds
is difficult to imagine because so many factors interact in complex
ways to shape the natural world around us. To answer the question of
the ecological significance of birds we have conducted a bird
exclusion experiment on an unprecedented scale. "The World without
Birds" consists of six walk-in cages, each of which excludes birds
from a 20 X 20 m area of natural Fynbos vegetation in the spectacular
Jonkershoek Valley in the Cape Fold Mountains of Africa. The
experimental setup, which is already in place, offers the opportunity
to test a range of ecological theories with direct implications for
conservation. Two important avenues of research remain open: How
important are birds as predators; and as vectors of mites and fungi
that live inside Protea inflorescences? An overarching aim is to gain
a general understanding of how networks of ecological interactions
form, and respond to species loss. Both projects have a strong
theoretical basis, while at the same time requiring detailed natural
history observations.
One of the most basic ecological questions concerns the control of
herbivore populations. In the trophic pyramid of life the herbivores
are sandwiched between the plants and the predators and their
abundance can potentially be controlled from the bottom up, by
plants, or from the top down, by predators. Will the loss of bird
precipitate an ecological cascade in whichherbivorous insect
populations explode and consume all the plants, or will the plants
defend themselves? Predation by birds may also affect the
architecture of the plant-herbivore interaction network in
fascinating ways. Networks may become more generalized if herbivores
spill over onto new host plant species in the absence of predators.
It will be fun to test these ideas with the powerful new network
analysis tools that have recently become available. An ambitious
student may additionally want to tackle evolutionary questions
related to the selectionpressures imposed by birds on herbivore populations.
Surprisingly, birds might be important links in intricate fungal
networks too. Many Proteas store their seed in cones in the canopy.
When fire kills the adult plant the cones open and the new generation
is released into the burned landscape. The cones are also home to
unique Ophiostoma fungi, which may help to protect the seeds against
attack from other malicious fungal species. It is now known that the
fungi are transmitted among flowering plants by Protea itch mites
(Proctolaelaps) which themselves are carried by flower visiting
beetles and birds. The bird exclosures provide the perfect setting
for assessing the role of birds as mite and fungal vectors and
secondarily for assessing the ecological significance of the fungi.
The Botany and Zoology Department at Stellenbosch University has a
vibrant Plant-Animal Interactions study group consisting of several
researchers and students. These projects are supervised by Prof.
Anton Pauw, Dr. Francois Roets and Prof. Cang Hui, who specialize in
evolutionary ecology, entomology and mathematical
ecologyrespectively. For primary consideration, applicants should
apply by 30 April 2014. Informal inquiries, priorto formal
application, are welcomed. To apply, please email: 1) a one-page
letter explaining why you are interested in this project, why you are
qualified for it and when you can begin; 2) your university
transcripts; 3) your curriculum vitae; 4) the names and email
addresses of three referees. The successful applicant will be
informed by mid May.
Anton Pauw, Department of Botany and Zoology, Stellenbosch
University, Private Bag 1X, Matieland 7602, South Africa,
<mailto:[email protected]>[email protected], Tel +27 21 808 3314, Cell
+27 83 682 4177.
