Glacier Bay, Alaska murrelet survey abundance estimates (KM_K) for survey year 2021

Tabular data in CSV form of marbled and Kittlitz's murrelet population status and trend estimates made during the SEAN monitoring program. A zip package containing three files is created for each survey. "Distance_Output_yyyy.csv" holds detection function parameters used for input. "Encounter_Rates_yyyy.csv" holds calculated encounter rates for each transect. "R_Output_yyyy.csv" holds estimates of encounter rate, density, and abundance by species for both status and trend - along with measures of statistical performance and confidence intervals for each.

This data product has been compared against the formal quality criteria specified in the protocol in use at the time of product creation, found to be in complete compliance, and accepted by the program lead for public dissemination. Deliverable KM_K is fully defined in the protocol document package available at NPS Data Store reference 2204691.

Please refer to the synthesis and program review report for monitoring of Kittlitz's murrelets in Glacier Bay National Park and Preserve which contains important findings that may affect the interpretation of abundance estimates (Hoekman, S. T. 2019. Kittlitz’s murrelet monitoring in Glacier Bay National Park and Preserve 2010–2018: Synthesis and program review. Natural Resource Report NPS/SEAN/NRR—2019/1957. National Park Service, Fort Collins, Colorado, https://irma.nps.gov/DataStore/Reference/Profile/2265288).

The report summarizes the results of murrelet monitoring from 2010-2018, assesses monitoring performance and capacity to meet protocol objectives, and provides recommendations for potential enhancements to the monitoring protocol. Hoekman (2019) identifies misidentification and partial identification of murrelets which can bias abundance estimation and spatially-explicit density estimates, particularly for rare species, such as Kittlitz’s murrelets.