Adelie Penguin nest locations on Bechervaise Island

Full description

This dataset represents the locations of Adelie Penguin nests in colonies K, L and Q on Bechervaise Island, Holme Bay, Antarctica. Attributes include colony, nest number and tag colour.

The dataset contains three files - an image file and two zip files.

The image file, mapping_grid.jpg, is a diagram showing the grid used for plotting the colony L nest locations.

The zip file, bech_penguin_nests.zip, contains shapefiles representing the Adelie Penguin nest locations, Bechervaise Island.

The zip file, transform_nests_colonyL.zip, provides further information about the georeferencing of the colony L nest locations.

Lineage

Progress Code: completed

Statement: The data includes a Qinfo attribute which identifies how the locations were captured. The Qinfo value is 547 for all the nests in colonies K and Q, except one which has a Qinfo value of 203. Qinfo = 547: Survey by Aaron Read (surveyor) using a Sokkia Powerset Total station 22 February 2002; estimated planimetric accuracy 0.05 m; estimated vertical accuracy 0.02 m. Qinfo = 203: Survey by Lisa Meyer (Australian Antarctic Division) in February 2000. The distance was measured from the colony marker to the nest then a compass bearing was taken from the nest back to the marker. The location was calculated from this data using the location of the colony marker. The marker for colony K was surveyed by Roger Handsworth (Australian Antarctic Division) in the same summer. The Qinfo values for the colony L nests are 548, 549, 550 or 595. Qinfo = 548: Locations plotted on a grid on paper by Lyn Irvine (Australian Antarctic Division) and later georeferenced. The grid was established in the following way. A rectangular border was surveyed around the penguin colony (colony L) using a theodolite. The eastern and western edges of this border were marked at 2m intervals with a measuring tape and stringlines run across the colony, splitting it into discrete 2m lengths. A small wooden grid, measuring 2 x 2m and split into squares of 20 x 20cm by stringlines, was run along the stringlines to accurately map the nests. The method of placing the border around the colony was as follows: (i) A mid-line was placed through the colony by lining up two datum points on Bechervaise Island and continuing the line north. (ii) The datum points lined up were the 'Bechervaise peak trig point' and the datum point situated above L colony at 67 degrees 35.244 minutes S, 62 degrees 48.760 minutes E. (iii) Two rectangular sections were surveyed on either side of the mid-line to enclose the colony. The section west of the mid-line measured 14m x 22m, while the section east of the mid-line measured 12m x 22m. Several control points were surveyed by Aaron Read. (Refer to the survey report for further information). Refer to the link below for a diagram showing the grid used for plotting the colony L nest locations. The locations of the penguin nests were hand drawn in the field on this local coordinate system and later digitised by John Cox (Drafting Officer, Australian Antarctic Division). The locations were then georeferenced using nest locations surveyed by Aaron Read as control. The georeferencing was done using a Spatial Adjustment with a Projective Transformation in ArcGIS 8.2. The RMS error achieved using all control points was 0.3m. It should be noted that when comparing the transformed data with the control points that there were a couple of 'outliers'. The UTM survey control coordinate data are quoted to 0.1m. Hence the locational accuracy for the transformed data are of the order of 0.5m. Qinfo = 549: Eyed in based on location indicated by Lyn Irvine on a print showing the colony L nest locations with Qinfo = 548. Qinfo = 550: Used to georeference the nest locations with Qinfo = 548. Surveyed by Aaron Read (refer to Qinfo = 547) then location adjusted in the georeferencing process to achieve the best fit with the data with Qinfo = 548. Refer to the link below for a zip file containing further information about the georeferencing. Qinfo = 595: Location estimated by Judy Clarke (Australian Antarctic Division) based on field experience and position of nest in relation to other nests.