An integrated model of scoter populations in eastern North America with a focus on estimating survival

Project Number: 176

Year Funded: 2024

Lead Institution(s): Pennsylvania State University

Project Lead: Frances Buderman

Email:

Collaborator(s): Tony Roberts (USFWS)

Location: Atlantic Flyway

Focal Species: Black Scoter (Melanitta americana), Surf Scoter (Melanitta perspicillata), White-winged Scoter (Melanitta delgandi)

Project Description: Sea duck demographic parameters are difficult for researchers to estimate at a range-wide scale because banding data is sparse, surveys are rarely conducted on a regular basis, and hunter harvest information is not abundant. Harvest regulations for scoters in the Atlantic Flyway have undergone two large changes in the last three decades. Metrics to determine if these changes in harvest regulations affect sea duck populations have been limited to comparing total estimated harvest, an imprecise measure for sea ducks. Population models integrating multiple sources of data may provide more precise estimates of harvest effects on sea duck demographic rates. The primary goal of this project is to obtain a better understanding of scoter abundance trends and survival rates using existing data. We propose to achieve our goal through the following objectives:

1. Build a hierarchical model that links observed population trend data with available demographic data to estimate accurate and precise survival rates.
2. Assess model performance using simulations to determine which parameters the survival estimate is most sensitive to and where managers should collect more data to most improve survival estimates.
3. Incorporate historical changes in harvest regulations as variables to estimate the effects of management actions.

This project will involve collating existing data, developing an integrated model utilizing those data, and assessing the performance of the model to determine the suitability for obtaining accurate and precise estimates of unobserved parameters and estimating the effect of harvest on those parameters.

Project Reports: