To broadcast or not to broadcast?To broadcast or not to broadcast?

How structure call-broadcast?How structure call-broadcast?

• all surveys broadcast same suite of speciesall surveys broadcast same suite of species• 6 pre-defined suites of species6 pre-defined suites of species• all surveys broadcast 5 speciesall surveys broadcast 5 species• all surveys include 5 min of broadcastall surveys include 5 min of broadcast• 1-13 spp in broadcast, survey duration varies1-13 spp in broadcast, survey duration varies

Species

Responded During:

Pass 1

Pass 2

Pass 3

Pass 4

Pass 5

BL

RA

LE

BI

SO

RA

VIR

A

KIR

A

AM

CO

KIRA 1             1    

VIRA                     1

 BLRA           1          

Species

Responded During:

Pass 1

Pass 2

Pass 3

Pass 4

Pass 5

LE

BI

SO

RA

VIR

A

CO

MO

LEBI       1  

VIRA             1  

 VIRA     1           1

11-min11-minsurveysurvey

ininLALA

9-min9-minsurveysurvey

ininMOMO

Maximize analytical capabilities of pooled data

Merge data to the extent

possible

Site

Species

Responded During:

Pass 1

Pass 2

Pass 3

Pass 4

Pass 5

BL

RA

LE

BI

SO

RA

VIR

A

KIR

A

CO

MO

AM

CO

LA  KIRA 1             1    

LA VIRA                     1

LA   BLRA           1          

MO  LEBI       1      

MO  VIRA              1        

MO   VIRA     1             1  

Compare first 9 min of each survey

Site

Species

Responded During:

Pass 1

Pass 2

Pass 3

Pass 4

Pass 5

BL

RA

LE

BI

SO

RA

VIR

A

KIR

A

CO

MO

AM

CO

LA  KIRA 1             1    

LA VIRA                     1

LA   BLRA           1          

MO  LEBI       1      

MO  VIRA             1        

MO   VIRA     1             1  

Site

Species

Responded During:

Pass 1

Pass 2

Pass 3

Pass 4

Pass 5

BL

RA

LE

BI

SO

RA

VIR

A

KIR

A

CO

MO

AM

CO

LA  KIRA 1             1    

LA VIRA                     1

LA   BLRA            1          

MO  LEBI       1      

MO  VIRA             1        

MO   VIRA     1             1  

Compare 8 min of similar survey effort

Site

Species

Responded During:

Pass 1

Pass 2

Pass 3

Pass 4

Pass 5

BL

RA

LE

BI

SO

RA

VIR

A

KIR

A

CO

MO

AM

CO

LA  KIRA 1             1    

LA VIRA                     1

LA   BLRA            1          

MO  LEBI       1      

MO  VIRA             1        

MO   VIRA     1             1  

Compare 5 min passive survey only

Detection probability may change Detection probability may change with marsh successionwith marsh succession

Detection probability may change Detection probability may change with marsh successionwith marsh succession

Detection probability may change Detection probability may change following wetland mgmt actionsfollowing wetland mgmt actions

Detection probability may change Detection probability may change following wetland mgmt actionsfollowing wetland mgmt actions

population density

plant communities

nesting stage

Detection probability likely varies spatiallyDetection probability likely varies spatiallyDetection probability likely varies spatiallyDetection probability likely varies spatially

Site

Species

Responded During:

Pass 1

Pass 2

Pass 3

Pass 4

Pass 5

BL

RA

LE

BI

SO

RA

VIR

A

KIR

A

CO

MO

AM

CO

LA  KIRA 1 0 0 0 0 0 0 0 1 0   0

LA VIRA 0 0 0 0 0 0 0 0 0 0 1

LA   BLRA 0 0 0 0 0 1 0 0 0 0    0

MO  LEBI 0 0 0 0 0   0 0 1   0  

MO  VIRA 0 0 0 0 0   0 1 0   0  

MO   VIRA 0 0 1 0 0   0 0 0   1  

Capture-recapture models to estimate vocalization probability

Species

Responded During: Call T

ype

Repeat

Distance (m

)

Pass 1

Pass 2

Pass 3

Pass 4

Pass 5

BL

RA

LE

BI

SO

RA

VIR

A

KIR

A

AM

CO

LEBI         1     1  coo    

CLRACLRA       11                      11   kekkek    

 AMBI                 s          

Species

Responded During: Call T

ype

Repeat

Distance (m

)

Pass 1

Pass 2

Pass 3

Pass 4

Pass 5

LE

BI

SO

RA

VIR

A

CO

MO

LEBI   1   1    coo    

LEBILEBI         11       11         kakkak    

 CLRA      1         1   purr    

20012001observerobserver

#1#1

20062006observerobserver

#2#2

Call types help reduce observer bias

Call types can help explain temporal Call types can help explain temporal or spatial differences in # countedor spatial differences in # counted

Call types can help explain temporal Call types can help explain temporal or spatial differences in # countedor spatial differences in # counted

Species

Responded During: Call T

ypes

Repeat

Distance (m

)

Pass 1

Pass 2

Pass 3

Pass 4

Pass 5

BL

RA

LE

BI

SO

RA

VIR

A

KIR

A

AM

CO

BLRA         1     1  kkrr N 80 

BLRA     1               1  grr N 30

PBGR                 1      owhoop N 230

observerobserver#1#1

observerobserver#2#2

Species

Responded During: Call T

ypes

Repeat

Distance (m

)

Pass 1

Pass 2

Pass 3

Pass 4

Pass 5

BL

RA

LE

BI

SO

RA

VIR

A

KIR

A

AM

CO

BLRA         1     1  kkrr Y 80 

BLRA     1               1  grr Y 30

PBGR                 1      owhoop Y 230

Recording repeats reduces observer bias

Was bird detected at previous point?Was bird detected at previous point? - local (50m) vs regional (400m) needs- local (50m) vs regional (400m) needs

Was bird detected at previous point?Was bird detected at previous point? - local (50m) vs regional (400m) needs- local (50m) vs regional (400m) needs

Multiple-observer surveys allow Multiple-observer surveys allow estimation of observer biasestimation of observer bias

- call type- call type- distance- distance- one line per bird- one line per bird

Multiple-observer surveys allow Multiple-observer surveys allow estimation of observer biasestimation of observer bias

- call type- call type- distance- distance- one line per bird- one line per bird

• Spp recorded at all sites Spp recorded at all sites • Spp recorded at all sites but calls not broadcastSpp recorded at all sites but calls not broadcast• Spp recorded at all sites but not 1 indiv per lineSpp recorded at all sites but not 1 indiv per line• Spp that some sites record, some do notSpp that some sites record, some do not

190 sites in 51 states/provinces190 sites in 51 states/provinces104 different broadcast sequences104 different broadcast sequences

~150,000 detections~150,000 detections3-day training workshops3-day training workshops

• Additional passive period at Additional passive period at endend• 3 counts per point per year3 counts per point per year

- variation in spp breeding dates- variation in spp breeding dates- high daily variation in detection - high daily variation in detection - many end up with 1-2 countsmany end up with 1-2 counts- still know very little about rare sppstill know very little about rare spp

• Additional passive period at Additional passive period at endend• 3 counts per point per year3 counts per point per year

- variation in spp breeding dates- variation in spp breeding dates- high daily variation in detection - high daily variation in detection - many end up with 1-2 countsmany end up with 1-2 counts- still know very little about rare sppstill know very little about rare spp

Where to place survey points?Where to place survey points?- water edge- water edge

- upland - upland edgeedge

- interior- interior

Where to place survey points?Where to place survey points?- water edge- water edge

- upland - upland edgeedge

- interior- interior

Surveying interior marshes would Surveying interior marshes would be disruptive in some regionsbe disruptive in some regions

Surveying interior marshes would Surveying interior marshes would be disruptive in some regionsbe disruptive in some regions

Record location of survey pointRecord location of survey point- water edge- water edge

- upland - upland edgeedge

- interior- interior

Record location of survey pointRecord location of survey point- water edge- water edge

- upland - upland edgeedge

- interior- interior