Scholarships for Graduate Studies at School of Biological Sciences,
University of Canterbury, Christchurch, New Zealand
Topic: Predation risk and the evolution of odours in island birds
Two fully funded Ph.D. scholarships are available to study the evolution of
odours in island birds and role these may play in increasing predation risk
from introduced mammalian predators.
Background to project:
Some New Zealand birds appear to have strong odours. For example, even to
the insensitive human nose, kiwi smell like ammonia, while the odour of the
kakapo has been likened to a dusty violin case. Strong odours are unusual in
birds, but common in mammals, which use odours for communication and
locating food. Preliminary work has revealed that strong odours may be
widespread among New Zealand birds, and that these odours arise from the
preen waxes produced in the uropygial gland. Preen waxes function to
maintain feathers, but may also attract predators that use olfaction to
locate prey. The first objective of this project is to determine if there
are differences in the composition of preen waxes between island and
continental birds and if these are the result of their differing
evolutionary histories with predatory mammals. The New Zealand area provides
an ideal system for studying odours and predation risk as the preen wax
composition can be compared across a number of island birds that evolved
without mammalian predators and their close phylogenetic relatives that
co-evolved with predators in continental Australia. The second objective of
this project is to then test whether differences in odours now put island
birds at greater risk from introduced mammalian predators. This study will
not only increase our understanding of the evolution and function of odours
in birds, but also determine whether these odours are now playing a
previously unrecognised role in the decline of island birds.
1) Ph.D. Project 1: Does the composition of preen wax and the ontogeny of
preen wax production vary with predation risk?
Predation is the greatest source of nest failure for continental birds, and
it is not unusual for 50-80% of nests to be lost to predators. Most
predation is due to mammals which locate nests through the odours of eggs or
nestlings. In contrast, birds on many oceanic islands, including New
Zealand, evolved in the absence of predatory mammals. This difference in
risk should select for reduced odours in continental species, in order to
camouflage nests from predators locating prey by olfaction. In this part of
the project, the candidate will test this hypothesis by comparing the
composition of preen waxes of a variety of island and continental birds. If
predation has shaped the evolution of avian odours, then the preen waxes of
island species should be relatively more volatile than those of their
closest continental relatives. Differences in the ontogeny of preen wax, and
the seasonal pattern of preen wax production are also expected to differ
between island and continental species. This project will involve field work
in New Zealand, Australia and several offshore islands.
2) Ph.D. Project 2: Do the odours of island birds increase their risk of
predation from exotic mammalian predators?
The vulnerability of island birds to exotic predators (e.g. rats, feral
cats) is well known and has been attributed to their behavioural naivety
towards novel predators and life histories that limit their ability to
tolerate high predation rates. As island birds also appear to have more
conspicuous odours than continental birds that co-evolved with mammals, the
production of more volatile preen waxes may also increase the probability
that island birds and their nests are detected by exotic mammalian
predators. In this part of this study, the candidate will test if the odour
of island birds and their nests increases the risk of predation by exotic
mammalian predators using a variety of field and lab-based studies. Field
work is required in New Zealand, Australia and offshore islands.
Applicants for either position require either a B.Sc. Honours or M.Sc. in
Biology. Candidates must be prepared to work in remote field locations and
travel for several months at a time. Scholarship includes stipend of $NZ
25,000 per year and cost of tuition fees. Duration of scholarship is 3
years. Non-residents of New Zealand will be required to obtain a student
visa for the period of study.
Application deadline: 1 March 2011
Start date: by negotiation but before 1 June 2011
To apply: Please send C.V. and cover letter to Dr. James Briskie (address
above) or by email (Jim.Briskie@canterbury.ac.nz).
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