Chemical signal
exploitation in predator prey interactions
Chief Investigators: Peter Banks |
Signalling lies
at the heart of behavioural and
evolutionary ecology, being the primary
means by which animals choose mates and
socialise. Yet social signals are open
to eavesdropping enemies, including
predators which may use prey cues to
improve their foraging. This research is
examining how potential prey balance the
risk of communication with the benefits,
and we focus on signal receivers who are
often most at risk from eavesdropping
predators.
Different sensory modes pose different
risks of signal exploitation, influenced
by the longevity of the signal (temporal
scale ) and the association between the
signal and its donor, receiver or
eavesdropper (spatial scale) (right). We
are using olfactory signallers and
predators for our model system because
they offer the greatest opportunity to
incorporate space and time into
experiments which are designed to
untangle the differing costs and
benefits to all players.
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Relationship
between spatial and temporal scales of
signals for the three main sensory
modes. |
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Conservation
Implications
In Australia, prey
naiveté to alien predators is one reason
why invasive species have been so
devastating, yet we know little of
how predators find their prey. This
research program also aims to develop a
new understanding about the exploitation
of social signals by both predator and
prey. In doing so we aim to generate new
theory on the reactive foraging
behaviour of predators and use this
theory to solve conservation problems.
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PhD Research
Projects
● Ben Russell (2006)
- The ecology of alien and native
predator and prey behavioural
interactions amongst Australian mammals
● Catherine Price (PhD) - Novel
strategies to protect prey from alien
predation
● Nelika Hughes (PhD) - Signal
exploitation in house mouse predator
prey interactions
Honours Research Projects
● Alex Carthey (2007)
– Odour and the spatial scale of
foraging in house mice, an olfactory
predator
● Alexis Watson (2007) – A test of the
prey archetype hypothesis for foraging
rats
● Joanne Lenehan (2003) - Mechanisms of
browsing deterrents to protect plants
from marsupials
● Candida Barclay (2004) - Mechanisms of
road crossing behaviour in small mammals
● Louise Pastro (2003) - House mouse
responses to chemical signal
exploitation in predator-prey
interactions.
● Jenna Bytheway (2005) The role of
odour in the foraging behavior of
rodents
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Recent Published
Results
● Pastro & Banks 2006 Behav Ecol Soc 60:101-7.
Aim: Is house
mice foraging sensitive to predation
risks associated with accumulations of
con-specific odours?
Methods: We applied 8ml or 40ml
of mouse urine to seed trays in open
(risky) & closed (safe) habitats
Results: Mouse foraging was not
sensitive to potential risks from
attracted predators (right) Giving up
densities (GUDs) were higher in open,
risky habitats but unaffected by the
addition of con-specific odours. What
then are the social costs /benefits of
receiving signals under such
eavesdropping predation risk? |
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Giving up
densities for house mice foraging in
seed trays treated with different doses
of mouse urine in open and closed
habitats in wheat fields.
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| ● Nelika Hughes
(PhD) – Receivers, not signallers pay
the cost of signal exploitation
(submitted).
Aim: Do
receivers trade off the predation risk
costs of receiving with signal value? Do
mice behave differently as receivers and
signallers under predation risk? |
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| Methods: We presented mice with their own odours
(low social receiving value) and those
from an unknown “intruder” (high social
receiving value) under high (cat urine
added) and low (water added) perceived
predation risk. |
The relative
rates of receiving and signalling in
response to odours of low (own) and high
(intruder) social value under high
(predator) and low (control) perceived
predation risk. |
| Results: Mice maintained high
receiving rates of high value intruder
odours under increased perceived
predation risk, but reduced receiving
rates under predation risk when the
odour was their own. In contrast, rates
of signalling did not vary with the
level of perceived predation risk.
The costs of
communication were borne more by the
receivers than the signalers. The
influence of the risks to receivers on
the evolution of communication systems
may have been underestimated. |
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