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To broadcast or not to broadcast?. How structure call-broadcast?. all surveys broadcast same suite of species 6 pre-defined suites of species all surveys broadcast 5 species all surveys include 5 min of broadcast 1-13 spp in broadcast, survey duration varies.
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How structure call-broadcast? • all surveys broadcast same suite of species • 6 pre-defined suites of species • all surveys broadcast 5 species • all surveys include 5 min of broadcast • 1-13 spp in broadcast, survey duration varies
Maximize analytical capabilities of pooled data 11-min survey in LA 9-min survey in MO
Detection probability may change following wetland mgmt actions
Detection probability likely varies spatially population density plant communities nesting stage
Capture-recapture models to estimate vocalization probability
Call types help reduce observer bias 2001 observer #1 2006 observer #2
Call types can help explain temporal or spatial differences in # counted
Recording repeats reduces observer bias observer #1 observer #2
Was bird detected at previous point? - local (50m) vs regional (400m) needs
Multiple-observer surveys allow estimation of observer bias - call type - distance - one line per bird
Spp recorded at all sites • Spp recorded at all sites but calls not broadcast • Spp recorded at all sites but not 1 indiv per line • Spp that some sites record, some do not
190 sites in 51 states/provinces 104 different broadcast sequences ~150,000 detections 3-day training workshops
Additional passive period at end • 3 counts per point per year • - variation in spp breeding dates • - high daily variation in detection • many end up with 1-2 counts • still know very little about rare spp
Where to place survey points? • - water edge • - upland edge • - interior
Surveying interior marshes would be disruptive in some regions
Record location of survey point • - water edge • - upland edge • - interior