The study group consisted of four subgroups:
The first subgroup was the White Leghorn, a domesticated breed of chicken. This breed is considered a “layer,” meaning that they are raised for egg production.
The other three subgroups were different breeds of the red junglefowl, the wild ancestor of all domestic chickens.
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The red junglefowl subgroups were: the unselected “ancestral” breed, and two lineages that had been divergently selected for high and low fear of humans. This was based on a fear-of-human test (see here for details), and has continued over 11 generations.
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Because domestication is believed to be a process initiated by selection for tameness, this “low fear” group can be thought of as a simulation of the domestication process.
The four subgroups were housed in pairs during testing:
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Four identical pens were constructed inside of the lab room, and the subgroups were housed in pairs throughout the testing period.
After the testing had concluded, the birds were given a colored leg band to indicate that they had already volunteered their time, then they were returned to their home pen (after leaving a nice Airbnb review).
In total, there were 7 pairs of White Leghorns (WL), 8 pairs of the unselected group (RJF), 8 pairs of the high fear group (HF) and 3 pairs of the low fear group (LF).
The testing period for each pair lasted for one week (Monday through Friday):
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Familiarization
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First, I familiarized the birds to my presence. This means that for the first three days of the testing week, I went into the test pen for each group and spent 15 minutes sitting and talking to them.
You can imagine that by week 7, I was running low on things to say…
After familiarization, I began with the behavioral tests:
Attentiveness
I showed the birds a colored bowl (Do they pay attention?)
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Choice task
The birds were given two bowls to choose from (How do they interact with the bowls?)
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Novel arena and fear response
The birds experienced a stressful situation, alone or with me in the room (How does human presence affect behavior?)
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