Banders without Borders Implementing a large-scale cooperative mark-resight study

Background Growing interest in AMOY research Growing interest in AMOY research Loosely organized cooperative effort over the past several years Loosely organized cooperative effort over the past several years Good communication among researchers – listserver, central website ( Research.htm) Good communication among researchers – listserver, central website ( Research.htm) Collaboration has allowed us to think through questions as a group and converge on solutions Collaboration has allowed us to think through questions as a group and converge on solutions We have an emerging consensus on: We have an emerging consensus on: –Winter and summer trapping methods –Organized color-banding scheme –Coordination with band supplier, banding codes –Age of banding for chicks

Background Success of the working group demonstrated with the coastwide aerial/boat/ground survey in Success of the working group demonstrated with the coastwide aerial/boat/ground survey in Obtained accurate and precise information on population size, distribution, and habitat use of wintering AMOY Obtained accurate and precise information on population size, distribution, and habitat use of wintering AMOY

Background Coordinated banding scheme Coordinated banding scheme –Triple layer size 6 Darvic color bands engraved with a 2-digit alphanumeric code –Supplier: Robin Haggie, HAGGIE ENGRAVING –Codes: 0,1,….9 A C E F H J K M N P R T U X Y –Removed to reduce error - B D G I L O Q S V W Z –625 Possible Combinations Current state colors Current state colors –Massachusetts – Yellow with Black codes –Virginia – Black with White codes –North Carolina – Green with White codes –South Carolina – Blue with White codes –Georgia – Red with White codes Future states Future states –White with Black codes –Orange with Black codes –Maroon with White codes

Background Band Placement Band Placement –Discussion over whether to use a single engraved color band or two identical bands, one on each leg –Advantages of single band: Costs less Costs less Less potential risk to bird Less potential risk to bird Faster banding time Faster banding time –Advantages of duplicate bands: Greater probability of detecting bands Greater probability of detecting bands Bands can be read from either leg, increasing resighting rate Bands can be read from either leg, increasing resighting rate Better return for equal banding effort Better return for equal banding effort –Over 200 birds in four states banded this year with duplicate bands No injuries or band difficulties seen No injuries or band difficulties seen Based on my experience, and reports from Georgia and Massachusetts, the duplicate bands improve resighting potential Based on my experience, and reports from Georgia and Massachusetts, the duplicate bands improve resighting potential Return on investment seems to justify the small additional cost Return on investment seems to justify the small additional cost –Recommendation: Continue using duplicate bands

Background Color-Banding began in North Carolina in 1999 Color-Banding began in North Carolina in 1999 South Carolina and Georgia began banding in 2001 South Carolina and Georgia began banding in 2001 Virginia and Massachusetts started in 2003 Virginia and Massachusetts started in 2003 Currently looking at expanding the effort into New Jersey Currently looking at expanding the effort into New Jersey

Background Each project has maintained a re-sight database for their birds Each project has maintained a re-sight database for their birds At NCSU I am building a central database for all inter-state resightings At NCSU I am building a central database for all inter-state resightings This database currently has 633 banding records from 5 states with 46 inter-state resights of individual birds This database currently has 633 banding records from 5 states with 46 inter-state resights of individual birds

Mark-Resight Poised to begin a designed resight effort Poised to begin a designed resight effort A carefully planned resight study has significant advantages over marking and waiting for opportunistic recoveries A carefully planned resight study has significant advantages over marking and waiting for opportunistic recoveries –Control or remove bias for quantitative analysis –Ensure equal probability of detection –Allocate effort across potential habitat –Result is unbiased survival estimate

Mark-Resight Important to have quantitative, defensible information Important to have quantitative, defensible information Results from opportunistic resighting can be highly biased Results from opportunistic resighting can be highly biased –Example: Consider two wintering habitat types; shell rakes and marsh roosts –Birds on shell rakes are easier to locate and bands are easier to see –These birds are more likely to get counted and have their bands reported than the birds in the less visible marsh habitat –Result will be a distorted view of the population if the visibility bias is not accounted for

Mark-Resight Differential access is another source of bias. Birds at remote roosts may be sampled infrequently or not at all. Differential access is another source of bias. Birds at remote roosts may be sampled infrequently or not at all. Sampling at the appropriate scale is crucial Sampling at the appropriate scale is crucial The entire Southeast region must be covered in a relatively short time window to avoid confounding mortality estimates with emigration The entire Southeast region must be covered in a relatively short time window to avoid confounding mortality estimates with emigration

Mark-Resight Ultimately we want to control bias and avoid uncertainty and heterogeneity in detection probabilities Ultimately we want to control bias and avoid uncertainty and heterogeneity in detection probabilities I will take an adaptive approach to implementing this project I will take an adaptive approach to implementing this project –Design sampling protocol –Conduct surveys –Model data, identify sources of bias –Adjust sampling approach With this approach our estimates will improve over time, and we can evaluate sources of uncertainty in the data With this approach our estimates will improve over time, and we can evaluate sources of uncertainty in the data Excellent tools are available for model selection. I will use Program Mark to chose between models and pinpoint sources of bias Excellent tools are available for model selection. I will use Program Mark to chose between models and pinpoint sources of bias

Mark-Resight: Objectives: Initiate a multi-year cooperative mark- resight study Initiate a multi-year cooperative mark- resight study Build a series of demographic models with good estimates of survival for adults, sub- adults and juveniles Build a series of demographic models with good estimates of survival for adults, sub- adults and juveniles Explore the potential for more complex models that incorporate movement and dispersal Explore the potential for more complex models that incorporate movement and dispersal

Mark-Resight: Survey Plan Identify existing roost sites Identify existing roost sites –Largely known from the recent aerial survey and from annual state counts in Virginia and South Carolina

Mark-Resight: Survey Plan Survey routes will be designed to cover all known roosts between mid-November and January Survey routes will be designed to cover all known roosts between mid-November and January –Full state surveys planned in New Jersey, Virginia, North Carolina, South Carolina, and Georgia. –Currently working on setting up Florida surveys.

Mark-Resight: Survey Plan Survey Protocol under development Survey Protocol under development –Roosting flocks will be surveyed within 2 hours of high tide –Flocks will be scanned for banded birds – we will investigate whether standardized digiscoping will provide a more accurate record –Flock size, age ratio, GPS location will be recorded for each flock

Conclusion Long term goal is to develop an adaptive, long term program to monitor the distribution, abundance, and demographic rates of AMOY along the eastern seaboard Long term goal is to develop an adaptive, long term program to monitor the distribution, abundance, and demographic rates of AMOY along the eastern seaboard Result will be a better understanding of the demographics, resource use, and movement of American Oystercatchers Result will be a better understanding of the demographics, resource use, and movement of American Oystercatchers Modeling will show population structure and trend and identify critical breeding productivity levels Modeling will show population structure and trend and identify critical breeding productivity levels Information will be directly applicable to setting management goals and policies Information will be directly applicable to setting management goals and policies By definition, this is a collaborative project By definition, this is a collaborative project Any publications would be a joint effort by working group collaborators Any publications would be a joint effort by working group collaborators