skylark: Skylark population data
In rtrim: Trends and Indices for Monitoring Data

The Skylark dataset that was included with the original TRIM software.

The dataset can be loaded in two forms. The skylark dataset is exactly equal to the data set in the original TRIM software:

Column	Type	Description
`site`	`integer`	Site number
`time`	`integer`	Time point coded as integer sequence
`count`	`numeric`	Counted skylarks
`Habitat`	`integer`	Habitat type (1, 2)
`Deposition`	`integer`	Deposition type (1, 2, 3, 4)

The current implementation is more flexible and allows time points to be coded as years and covariates as factors. The skylark2 data set looks as follows.

Column	Type	Description
`site`	`factor`	Site number
`year`	`integer`	Time point coded as year
`count`	`integer`	Counted skylarks
`Habitat`	`factor`	Habithat type (`dunes`, `heath`)
`Deposition`	`integer`	Deposition type (1, 2, 3, 4)
`Weight`	`numeric`	Site weight