Question-and-Answer Service Student Guide
April QAS 4/10/18
Questions 42-52 are based on the following
passage and supplementary material.
This passage and accompanying figures are adapted from
Sam Hardman, “Gouldian Finches’ Head Colour Reflects
Their Personality.” ©2012 by Ecologica.
In order to determine if head colour really does
indicate personality traits in Gouldian finches,
researcher Leah Williams and her colleagues tested a
number of predictions. First they looked at pairs of
black-headed birds, which were expected to show less
aggression towards each other than pairs of
red-headed birds. This makes sense since red-headed
birds had previously been found to exhibit higher
levels of aggression.
The second prediction was that red-headed birds
should be bolder, more explorative and take more
risks than black-headed birds. This hypothesis is
based on previous studies of other species that have
shown a correlation between aggression and these
behavioural characteristics. However, there is
another possibility. Red-headed birds could take
fewer risks for two reasons: first, they may be more
conspicuous to predators due to their bright
colouration and second, it may pay black-headed
birds to take more risks and be more explorative so
they find food resources before the dominant
red-headed birds do.
In order to test the first prediction, paired birds of
matching head colour were moved into an
experimental cage without food. After one hour of
food deprivation a feeder was placed into the corner
of the cage where there was only enough room for
one bird to feed at a time. Aggressive interactions
such as threat displays and displacements were then
counted over a 30-minute period. The results were
striking. Red-headed birds were significantly and
consistently more aggressive than black-headed
birds.
To test the birds’ willingness to take risks, the
researchers deprived the birds of food for one hour
before the birds’ feeder was replaced. After the birds
had calmly begun to feed, a silhouette of an avian
predator was moved up and down in front of the
cage to scare the birds from the feeder. The time it
took for them to return to the feeder was taken as a
measure of their willingness to take risks. Birds that
returned quickly were considered to be greater risk
takers than those that were more cautious.
This time the results were surprising. Red-headed
birds were considerably more cautious than those
with black heads at returning to the feeder after a
“predator” had been introduced. They took on
average four times longer to begin feeding again than
the less aggressive black-headed birds.
Finally, the researchers investigated the birds’
interest in novel objects or “object neophilia,” which
is defined in the paper as “exploration in which
investigation is elicited by an object’s novelty.” To do
this a bunch of threads were placed on a perch within
the cage. The time taken for the birds to approach
the threads within one body length and to touch
them was recorded over a one-hour period. In line
with the results from the risk-taking experiment it
was found that the aggressive red-headed birds
showed less interest in novel objects than did black-
headed birds. The difference is not as striking as it
was in the previous experiments but was statistically
significant nonetheless.
These experiments were repeated after a
two-month interval and showed that different birds
differed in their responses but the responses of
individual birds were consistent over time. Head
colour was found to predict the behavioural
responses of the birds. Red-headed birds were more
aggressive than black-headed birds but took fewer
risks and were not explorative.
What is surprising about these results is that
aggression does not correlate with risk-taking
behaviour. However, the researchers do provide a
convincing explanation, suggesting that red
colouration has been found to be conspicuous
against natural backgrounds, and more conspicuous
birds have been found to suffer higher predation
rates. Thus, selection could favour more conspicuous
red-headed birds taking fewer risks.
Interestingly, boldness [in investigating novel
objects] and risk-taking behaviours were found to be
strongly correlated: regardless of head colour they
always occurred together, forming a “behavioural
syndrome.” This implies that there is selection in
favour of specific combinations of traits and of head
colour in relation to those traits. Selection favours
aggression in red-headed birds and the boldness/
risk-taking behavioural syndrome in black-headed
birds. This makes sense when you consider the high
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