California Department of Fish and Wildlife

BIOS Tutorial: Tricolored Blackbird


Analyzing Statewide Tricolored Blackbird Data

In the BIOS Mapviewer:

  • First, open the BIOS Data Catalog by clicking the "Add BIOS Layers" tool (1).
  • Then, filter the list of Available Layers by selecting the "Layer Name" filter field (2) and entering the search term "tricolor" in the Search Term box (3).
  • Add the filter (4) and then check the "Tricolored Blackbird Breeding Surveys" item (5) to add it to the "Checked Layers" box on the right.
  • Then click the "Add Checked Layers to Map" button (6) to add this layer to the map.

Back in the map:

  • Click the checkbox next to the added layer name to turn it on (7).
  • Click on the layer name text to make it the "Active Layer".
  • Finally, click the "Refresh Map" button to reflect your changes.

Next, select active nesting colonies:

  • Open the attribute query dialog box by selecting the "Attribute query" tool (8).
  • Clear any previous query parameters (9), then double-click the "nesting" item in the right query panel (10)
  • Click the "=" operator (11)
  • Double-click the "y" attribute (12).
  • Execute the query (13). This query will select only nesting colonies recorded as active by survey observers.

Note that the colony locations considered to be active during the survey are now highlighted in yellow (14). In addition, the results panel is now populated with the selected records (15), and a small yellow icon (16) indicates that the active layer has a selected record set.

Now we will reduce the selected set of active nest colonies to only those with a nesting substrate that includes blackberries.

  • Open the "Attribute query" tool (17) and clear any previous query conditions (18).
  • Begin constructing the query by double-clicking the "substrate" item in the right query panel (19), followed by the "like" operator (20) and the "blackberries" item in the left query panel (21).
  • The "like" operator allows you to put wildcard characters in your query. This will result in the selection of not just entries that are an exact match to the value you enter, but also all entries that contain the value you enter along with possibly additional text before or after the value. So, you would end up with all values equal to "blackberries", but also possibly "blackberries, willows" and "himalaya blackberries". To take advantage of this, you need to place "%" characters (the percent sign) at the beginning and the end of the value. So manually change "blackberries" to "%blackberries%" in the Query Command window.
  • Next choose the "select from set" option near the bottom of the query dialog box (22), and execute the query (23).

Note that the selected records center around the greater Sacramento region (24), and information regarding each selected colony location which was identified as active (25) and occurring in a blackberry or mixed-blackberry substrate (26).