Positive correlation between Ammospiza caudacuta (Saltmarsh Sparrow) capture and productivity supports use of a novel rapid assessment monitoring protocol

Salt marshes in the northeastern United States provide critical breeding habitat for tidal marsh specialist birds like the Saltmarsh Sparrow (Ammospiza caudacuta). The Saltmarsh Sparrow population has declined by nine percent annually, necessitating immediate conservation actions for this vulnerable species. However, estimating species vital rates across a large geographic region is logistically challenging and cost prohibitive. Therefore, we developed and tested a rapid assessment monitoring protocol focused on reproductive metrics to enhance future conservation planning.

We used three years of intensive demographic data from 12 sites to estimate daily nest survival, nest period success, fledglings produced per female, and successful broods per female. We implemented the rapid assessment protocol co-located at intensive sites in the same years to estimate the number of captured females and juveniles. We used Pearson’s correlation analyses to determine the association of intensive metrics with rapid metrics. We found that the sum of Saltmarsh Sparrow female and juvenile captures was positively correlated with daily nest survival, nest period success, fledglings produced per female, and successful broods per female. Our results demonstrate that fixed-effort mist-netting from our rapid assessment protocol is an informative and time-efficient sampling method that can aid in making informed management decisions related to Saltmarsh Sparrow conservation.

Methods
Our data was collected through numerous field seasons by trained surveyors in tidal mashes across the northeastern United States. At each field site an array of different survey methods were utilized inculding mark-recpature techniques for survival analyses, and nest searching and monitoring for nest survival analyses. Our survey data was imported to the SHARP Demographic Database (https://sharp-qa.azurewebsites.net/) and maintained and QAQC'd by researchers at collaborating universities (University of Maine, University of Nuw Hampshire, University of Connecticut, State UNiversity of New York SChool of Environmental Science and Forestry, and University of Delaware).