ex0218: Peter and Rosemary Grant's Finch Beak Data

In Sleuth3: Data Sets from Ramsey and Schafer's "Statistical Sleuth (3rd Ed)"

Description

In the 1980s, biologists Peter and Rosemary Grant caught and measured all the birds from more than 20 generations of finches on the Galapagos island of Daphne Major. In one of those years, 1977, a severe drought caused vegetation to wither, and the only remaining food source was a large, tough seed, which the finches ordinarily ignored. Were the birds with larger and stronger beaks for opening these tough seeds more likely to survive that year, and did they tend to pass this characteristic to their offspring? The data are beak depths (height of the beak at its base) of 751 finches caught the year before the drought (1976) and 89 finches captured the year after the drought (1978).

Usage

ex0218

Format

A data frame with 840 observations on the following 2 variables.

Year

Year the finch was caught, 1976 or 1978

Depth

Beak depth of the finch (mm)

Source

Ramsey, F.L. and Schafer, D.W. (2013). The Statistical Sleuth: A Course in Methods of Data Analysis (3rd ed), Cengage Learning.

References

Grant, P. (1986). Ecology and Evolution of Darwin's Finches, Princeton University Press, Princeton, N.J.

See Also

case0201

Examples

str(ex0218)

Example output

'data.frame':	840 obs. of  2 variables:
 $ Year : int  1976 1976 1976 1976 1976 1976 1976 1976 1976 1976 ...
 $ Depth: num  6.1 6.1 6.2 6.3 6.2 6.3 6.5 6.5 6.6 6.7 ...

Sleuth3 documentation built on May 2, 2019, 6:41 a.m.