Students & Associates
Honorary Research Associate
Dr Thomas Flower
PhD (University of Cambridge, UK), MSc (University of Pretoria, SA), BSc Hons
(University of Bristol, UK)
Tom’s principal research interest is in behavioural ecology, specifically why
animals behave the way they do and how they acquire and produce their
behaviour. Tom’s research has investigated deception, animal communication,
cooperative breeding, kleptoparasitism, vocal mimicry, animal mutualisms and
brood parasitism. Tom is additionally involved in research on behavioural
flexibility in response to environmental change and the conservation of a
critically endangered bird, the Raso Lark.
Tom did his PhD at the University
of Cambridge with Prof. Nick Davies investigating food theft and deception
by an African bird, the fork-tailed drongo (2008-11). Prior to this, Tom was
the manager of the Kalahari Meerkat Project and Kuruman River Reserve
(2004-07), run by Prof. Tim Clutton-Brock (University of Cambridge) and
Prof. Marta Manser (University of Zurich), which investigates the
evolutionary causes and ecological consequences of cooperative breeding in
meerkats (Suricata suricatta). While managing the meerkat project, Tom did
his MSc research (2006-07) on the factors affecting competition for food in
meerkats and more specifically, whether meerkats use competition for food as
a means of suppressing their reproductive competitors. Tom has also worked
on conservation of the critically endangered Raso Lark (2008-2011), whose
entire population is confined to a single island in the Cape Verde’s off the
west coast of Africa.
Tom joined the Fitz in January
2012 to begin a postdoctoral research fellowship investigating the
strategies employed by animals in deceptive communication. In 2013 Tom was
awarded a University Research Council Postdoctoral Fellowship to continue
this research and further investigate how animals acquire and produce their
Tom uses a combination of observations and experiments to investigate the
deceptive alarm calling behaviour of a habituated and colour ringed
population of wild Fork-tailed Drongos (Dicrurus adsimilis) in
the southern Kalahari Desert. This work is undertaken in collaboration with
Dr Amanda Ridley (University of Western Australia). Tom’s previous PhD
research showed that drongos steal food from other animals (kleptoparasitism)
and commonly do so by producing false alarm calls, including mimicked alarms
of other species, which cause targeted individuals to drop their food and
flee to cover. But just as in Aesop’s fable ‘The boy who cried wolf’, other
species cease responding to drongo alarm calls when false alarms are made
too often. However, drongos can evade this problem by employing vocal
mimicry to vary their false alarm calls and thus keep their deception racket
going. This fascinating behaviour raises a number of important questions
about animal communication and Tom is currently investigating:
(i) How deceptive signallers use feedback from their receivers behaviour to
vary their communication strategies.
The Kuruman River Reserve also hosts the Pied
Babbler Research Project run by Dr Ridley and the Kalahari
Meerkat Project run by Prof. Tim Clutton-Brock and Prof. Marta Manser.
It has therefore been possible to closely observe drongo interactions with
the habituated populations of pied babblers(Turdoides bicolor) and meerkats (Suricata
suricatta), studied by these projects which has greatly assisted drongo
(ii) How drongos acquire the ability to produce deceptive alarm calls.
collaboration with Dr Claire Spottiswoode,
Tom has initiated research investigating coevolution between the African
Cuckoo and its host, the Fork-tailed Drongo. African Cuckoos lay their eggs
in the nests of drongos and upon hatching, the cuckoo chick evicts the
drongo’s own eggs and chicks from the nest, thereby monopolizing parental
care for itself. Drongo eggs are highly variable in colour and pattern and
evidence suggests that drongos reject cuckoo eggs dissimilar from their own.
However, the cuckoo’s eggs are similarly variable and appear to mimic those
of the drongos making rejection decisions difficult and potentially highly
costly if a mistake is made. Dr Flower and Dr Spottiswoode are therefore
investigating whether drongos in populations more frequently exposed to
cuckoos are more likely to reject cuckoos eggs. This could have resulted in
selection for new drongo egg pattern/colour morphs, resulting in greater egg
variability in more exposed populations of drongos and comparable variation
in the eggs of cuckoos that parasitize them. Additionally, Dr Flower and Dr
Spottiswoode will exploit the wealth of knowledge on the life histories of
drongos in Tom’s Kalahari population to investigate how age, sex and cuckoo
parasitism experience affect egg rejection decisions by drongos.
Behaviour and Conservation
While at the Fitz. Tom has
additionally collaborated on several projects employing research on animal
behaviour to inform conservation. With Dr Lorien Pichegru, Tom has
investigated the behavioural flexibility of breeding African Penguins in
response to human disturbance. With Dr Rowan Martin, Dr Susan Cunningham and
Dr Ben Smit, he has investigated how environmental change, and specifically
increasing temperatures, will affect bird population viability. Finally,
with Davide Gaglio and Dr Timothée Cook, Tom is investigating how
kleptoparasitism by Hartlaub’s Gull affects the breeding success of Swift
Inge Adams. Context-specific alarm mimicry by
the Fork-tailed drongo. BSc Honours. (Supervisors: Thomas Flower, Peter
Bruce Baigrie. 2013. Mutualism benefits and
the evolution of an interspecific sentry call in associations between
Sociable Weavers and Fork-tailed Drongos. BSc Honours. (Supervisors: Thomas
Flower, Peter Ryan).
Recent peer-reviewed publications
Baigrie, B.D., Thompson, A.M. & Flower, T.P. 2014. Interspecific signaling
between mutualists: food-thieving drongos use a cooperative sentinel call to
partners. Proceedings of the Royal Society B 281(1791):20141232.
Gribble, M. & Ridley, A.R. 2014. Deception by flexible alarm mimicry in an
African Bird. Science, 344, 513-516. Doi: 10.1126/science.1249723
Flower, T.P., Child, M.F. & Ridley, A.R. 2013. The ecological economics of
kleptoparasitism: pay-offs from self-foraging versus kleptoparasitism.
Journal of Animal Ecology 82:245-255.
Brooke, M.de L., Flower, T.P., Campbell, E.M., Mainwaring, M.C., Davies,
S. & Welbergen, J. A. 2012. Rainfall-related population growth and adult sex
ratio change in the Critically Endangered Raso lark (Alauda razae).
Animal Conservation doi:10.1111/j.14691795.2012.00535.x
Child, M. F., Flower, T.P. & Ridley,
A.R. 2012. Investigating a link between bill morphology, foraging ecology
and kleptoparasitic behaviour in the fork-tailed drongo Dicrurus adsimilis.
Animal Behaviour, 84, 1013-1022.
Flower, T.P. & Gribble, M. 2012. Kleptoparasitism by attacks versus false
alarm calls in fork-tailed drongos. Animal Behaviour 83:403-410.
Nielsen, J.F., English, S., Goodale-Copestake, W.P., Wang, J., Walling, C.A., Bateman, A. W.,
Flower, T.P., Sutcliffe, R.L., Samson, J., Thavarajah,
N.K., Kruuk, L.E., Clutton-Brock, T.H. & Pemberrton, J.M. (in press).
Inbreeding and inbreeding depression of early life traits in a cooperative
mammal. Molecular Ecology. doi: 10.11.11/J.1365-294X.2012.05565.x
Flower, T.P. 2011. Fork-tailed drongos use deceptive mimicked alarm calls to
steal food. Proceedings of the Royal Society B-Biological Sciences.
Brooke, M.de L., Flower, T.P. & Mainwaring, M.C. 2010. Scarcity of females
may constrain population growth of threatened bird species: case notes from
the Critically Endangered Raso Lark Alauda razae. Bird Conservation
Clutton-Brock, T.H., Hodge, S.J., Flower, T.P., Spong, G.F. & Young, A.J.
2010. Adaptive Suppression of Subordinate Reproduction in Cooperative Mammals.
The American Naturalist, 176:664-673. doi: 10.1086/656492
Copyright: Percy FitzPatrick Institute of African Ornithology 2014
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