Assessing habitat fragmentation in birds using radio-frequency ID (RFID) systems.

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Forest birds, such as chickadees, are reluctant to cross large habitat openings, such as those created by pipeline or transmission line rights-of-way. For nearly two decades, monitoring of willingness of forest-generalist birds to cross such openings has been used by researchers and consultants conducting Environmental Assessments to determine the impacts of habitat fragmentation. One typical technique used to test gap-crossing is playback of chick-a-dee mobbing calls (used when harassing small predators, like owls or falcons) from one side of a habitat gap, with researchers measuring the route and time taken for birds to cross the gap and approach the speaker. A long latency to respond and use of longer routes to minimize distance of crossing open spaces are considered as evidence of reluctance in gap-crossing. This technique, however, suffers from problems associated with motivation - if gathered birds perceive that the predator is on the other side of a large opening, an unwillingness to cross this gap may simply reflect their perception that the threat is distant, rather than unwillingness to make crossings. Further, the technique measures gap-crossing decisions on only a short temporal scale (several minutes). We propose to use feeding stations fitted with radio-frequency ID (RFID) antennas to track PIT-tagged (passive integrated transmitters) birds as an alternate means of assessing gap crossing decisions. Rather than using a negative stimulus (presence of a predator) to attract birds, they use a positive reinforcer (food). Thus, there is a positive enticement that would encourage gap crossing. Second, movement patterns of birds can be tracked over extended periods with the use of PIT tags and RFID units (days to months), providing detailed long-term assessment of spatial use of the landscape. This novel application of RFID tracking has potential to increase the accuracy of assessing habitat fragmentation issues associated with seismic lines, transmission corridors and pipeline routes. We will be developing and testing this methodology with Environmental Dynamics Inc - a consulting firm specializing in environmental assessments - to determine its potential application to the field.