Dove experiment In a study to observe how the Barbary dove's sleep patterns are affected in the presence of various flock sizes , D. W. Lendrum set out to prove that bigger flocks would decrease the overall vigilanceand that an apparent increase in predation risk by being surrounded by fewer doves would harm their sleep cycle. To start the study the doves would sleep in isolation and for the study they would be caged alone , or in pairs of  two, three or six doves. They would proceed to put the doves into two different environments. One trial condition included Lendrum walking by the cage unaccompanied. This was the calm environment, while the other was with a domesticated ferret accompanying Lendrum. This was an aggressive environment. Birds were observed midday between 10 am and 12 pm. Lendrum discovered that birds that slept in the low-risk cage (no ferret) spent substantially more time with their eyes closed than those that were in the high-risk cage (ferret) . Lendrum also collected data for the study that showed the frequency of the dovesin both eye-opened sleep and closed-eye sleep state. The data showed that flocking was associated with an increase in the bird's overall eye closure time . Flocking also affected the duration spent in the eye-opening state. Data showed a decrease in the amount of eye-opening when in the presence of a flock . In the presence of a predator, Lendrum found that the doves exhibited higher levels of individual vigilance and an increase of time sleeping with their eyes opening. This, in turn, limited the active-sleep component of the dove's total sleep time.
Dove experiment In a study of how the Barbary dove's sleep patterns are affected by flock size , D. W. Lendrum intended to prove that larger flocks reduced overall vigilance, and the apparent increase in predation risk of a smaller flock would harm the doves' sleep cycle. At the beginning of the study, the doves were caged alone or in pairs of cages containing two, three or six . They were then placed in one of two environments. In the calm environment, Lendrum walked alone past the cage between 10 am and noon; in the aggressive environment, Lendrum walked past the cage with a domesticated ferret at the same time of day. Lendrum discovered that the birds in the calm environment spent substantially more time with their eyes closed than those in the aggressive environment . Lendrum collected data on the doves' opened- and closed-eye sleep ; flocking was associated with an increase in a bird's overall eye-closure time and a decrease in its amount of eye-opening . In the presence of a predator, Lendrum found that the doves exhibited higher levels of individual vigilance and increase in open-eye sleep; this reduced the active-sleep component of their total sleep time.
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To start the study the doves would sleep in isolation and for the study they would be caged alone ,
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doves. They would proceed to put the doves into two different environments. One trial condition included Lendrum walking by the cage unaccompanied. This was the calm environment, while the other was
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accompanying Lendrum. This was an aggressive environment. Birds were observed midday between 10 am and 12 pm.
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