In mid-February, I helped capture a few of the adult Crested Caracara we had been monitoring at nest sites. Adults were still tending to their nests and chicks, and were very territorial. This makes it easy to target the area near the nest to trap the adults. We used a “lure” bird, a captive Crested Caracara to draw in our target adults. Using a lure bird has proven to be the most effective way to trap adult Crested Caracaras, who are quite upset to see an intruder on the core of their territory. During trapping, we placed the lure bird on a tie-out in the safe zone of a type of elongated Bow net, and as the target bird walked in to the capture zone, the trigger was pulled.
We banded both Crested Caracaras that we captured with the typical USFWS metal band, and gave each a GPS satellite transmitter that will give a good idea of territory size over time. Both adults are on land adjacent to proposed development sites, which have the potential to drastically change their territory sizes.
Source: Capture Methods for Crested Caracaras. Joan L. Morrison and Steven M. McGehee. Journal of Field Ornithology Vol. 67, No. 4 (Autumn, 1996), pp. 630-636