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.
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.
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:
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):
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:
I showed the birds a colored bowl (Do they pay attention?)
The birds were given two bowls to choose from (How do they interact with the bowls?)
Novel arena and fear response
The birds experienced a stressful situation, alone or with me in the room (How does human presence affect behavior?)