Western Bluebird

The Western Bluebird dataset is consumed from an external Open Geospatial Consortium Web Mapping Service (OGC WMS) via the following URL endpoint and layer name:
  URL:
  https://www.sciencebase.gov/geoserver/CONUS_HabMap_2001/wms
Layer name: Western Bluebird (Sialia mexicana) bWEBLx v1

OpenLayers

If you are developing in OpenLayers 2, you will want to use the OpenLayers WMS class.

An example of your solution might look similar to the code below.

layer = new OpenLayers.Layer.WMS(
    "Western Bluebird"",
    "https://www.sciencebase.gov/geoserver/CONUS_HabMap_2001/wms",
    {
      layers: Western Bluebird (Sialia mexicana) bWEBLx v1,
      transparent: "true",
      format: "image/png"
    },
    {}
);

map.addLayer(layer);