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Explanations to the file "gridcell.csv"
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gridcell.csv is a semicolon-delimited table consisting of 10 columns and 1208 rows (excluding a row with column names).

Each row corresponds to one grid cell at the coast of Northern Norway. The columns contain the following data,

lat:	northern latitude of the centre of the grid cell [degrees]
lon:	eastern longitude of the centre of the grid cell [degrees]
mainld:	variable indicating whether the grid cell contains coastline of the mainland  [0, no; 1, yes]
island:	variable indicating whether the grid cell contains coastline of any island(s) [0, no; 1, yes]
coast:	variable indicating the definition of coastal grid cells suitable as seabird colonies [0-4]
pairs:	number of pairs of cliff-nesting seabirds breeding within the grid cell [count]
order:	variable indicating the order of grid cells if arranged linearly from southwest to northeast [integer]
shelf:	shortest distance from the coastline within the grid cell to the shelf break [km]
protr:	shortest distance from the outermost point of the coastline within the grid cell to the average coastline [km]
protx:	variable indicating whether "protr" could be estimated unambiguously [0, no; 1, yes]

The grid has a latitudinal resolution of 0.075 degrees and a longitudinal resolution of 0.15 degrees. (This means, e.g., that the southwestern ["lower left"] corner of a grid cell is 0.075 degrees to the west and 0.0375 degrees to the south of its centre, which is provided in this file.)

A grid cell may contain coastline of both mainland and islands. Grid cells without any coastline are excluded, as are gridcells outside the range of the seabird colonies considered (i.e., to the south of Lovunden and to the east of Ranvika; cf. Supplementary Table 4). Four different sets of grid cells were considered as potential sites for seabird colonies. The widest set consists of all cells that have "coast" >= 1. The narrowest set is indicated by "coast" = 4.

Numbers of breeding pairs are based on the maximum count available for each grid cell. Only counts of at least 5000 pairs are included (i.e., counts below 5000 are represented by 0).

Protrusion (column "protr") is positive for grid cells that lie outside (seaward of) the average coastline, and negative for grid cells that lie inside (landward of) the average coastline. The average coastline is estimated using major axis regression of the outermost points of the grid cells within stretches of 80 km (40 km on both sides of each grid cell, only considering grid cells with "coast" = 4). For some grid cells (those with "protx" = 0), protrusion was not estimable in the way described, and approximate values were assigned manually.

Missing value are indicated by "NA". Missing values occur only in the columns "order" and "protr" (for grid cells that have "coast" < 4).

For questions, please contact Hanno Sandvik (hanno@evol.no).