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Dataset from Allison and Cicchetti (1976) of 62 mammal species on the interrelationship between sleep, ecological, and constitutional variables. The dataset contains missing values on five variables.

Format

mammalsleep is a data frame with 62 rows and 11 columns:

species

Species of animal

bw

Body weight (kg)

brw

Brain weight (g)

sws

Slow wave ("nondreaming") sleep (hrs/day)

ps

Paradoxical ("dreaming") sleep (hrs/day)

ts

Total sleep (hrs/day) (sum of slow wave and paradoxical sleep)

mls

Maximum life span (years)

gt

Gestation time (days)

pi

Predation index (1-5), 1 = least likely to be preyed upon

sei

Sleep exposure index (1-5), 1 = least exposed (e.g. animal sleeps in a well-protected den), 5 = most exposed

odi

Overall danger index (1-5) based on the above two indices and other information, 1 = least danger (from other animals), 5 = most danger (from other animals)

Source

Allison, T., Cicchetti, D.V. (1976). Sleep in Mammals: Ecological and Constitutional Correlates. Science, 194(4266), 732-734.

Details

Allison and Cicchetti (1976) investigated the interrelationship between sleep, ecological, and constitutional variables. They assessed these variables for 39 mammalian species. The authors concluded that slow-wave sleep is negatively associated with a factor related to body size. This suggests that large amounts of this sleep phase are disadvantageous in large species. Also, paradoxical sleep (REM sleep) was associated with a factor related to predatory danger, suggesting that large amounts of this sleep phase are disadvantageous in prey species.

Examples

sleep <- data(mammalsleep)