## Cuckoo Eggs Data

### Description

Length and breadth measurements of 120 eggs lain in the nests of six
different species of host bird.

### Usage

cuckoos

### Format

This data frame contains the following columns:

- length
the egg lengths in millimeters

- breadth
the egg breadths in millimeters

- species
a factor with levels
`hedge.sparrow`

,
`meadow.pipit`

,
`pied.wagtail`

,
`robin`

,
`tree.pipit`

,
`wren`

- id
a numeric vector

### Source

Latter, O.H. (1902). The eggs of Cuculus canorus. An
Inquiry into the dimensions of the cuckoo's egg and the relation of the
variations to the size of the eggs of the foster-parent, with notes on
coloration, &c. Biometrika i, 164.

### References

Tippett, L.H.C. 1931: "The Methods of Statistics". Williams & Norgate,
London.

### Examples

print("Strip and Boxplots - Example 2.1.2")
attach(cuckoos)
oldpar <- par(las = 2) # labels at right angle to axis.
stripchart(length ~ species)
boxplot(split(cuckoos$length, cuckoos$species),
xlab="Length of egg", horizontal=TRUE)
detach(cuckoos)
par(oldpar)
pause()
print("Summaries - Example 2.2.2")
sapply(split(cuckoos$length, cuckoos$species), sd)
pause()
print("Example 4.1.4")
wren <- split(cuckoos$length, cuckoos$species)$wren
median(wren)
n <- length(wren)
sqrt(pi/2)*sd(wren)/sqrt(n) # this s.e. computation assumes normality