Monitoring Kittlitz’s and marbled murrelets in Glacier Bay National Park and Preserve: 2013 annual report
Hoekman SJ, Sergeant CJ, Johnson WF. 2014. Monitoring Kittlitz’s and marbled murrelets in Glacier Bay National Park and Preserve: 2013 annual report. Natural Resource Technical Report. NPS/SEAN/NRTR—2014/841. National Park Service. Fort Collins, Colorado
Since 2009, the National Park Service’s Southeast Alaska Inventory and Monitoring Network (SEAN) has monitored population abundance and trend of Kittlitz's (KIMU) and marbled murrelets (MAMU) in Glacier Bay National Park and Preserve, an important summer residence for both species. This annual report summarizes data in a concise format and focuses on current population abundance and spatial distribution. Monitoring focuses on KIMU, with secondary consideration of MAMU. KIMU are an open-water, pursuit forager whose reliance on pelagic prey sources link their habitat use in some areas to dynamic physical habitat variables such as glacial extent and oceanography. The SEAN uses boat-based line transect surveys to estimate species-specific, on-water density and abundance of murrelets, accounting for detection probability and unidentified murrelets. We surveyed 214 km on 40 transects from 6-13 July 2013 across the 1,170 km2 survey area in Glacier Bay proper. We estimated an abundance of 7,210 KIMU (SE = 2,046) and 84,428 MAMU (SE = 15,394). From 2009 to 2013, KIMU abundance estimates have ranged from 7,210 to 16,469 with annual changes of -56% to 120%, while MAMU have ranged from 28,978 to 84,428 with annual changes of -29% to 113%. 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. This season, in cooperation with the University of Montana and USFWS, the SEAN participated in field trials designed to assess the magnitude of Kittlitz’s versus marbled murrelet identification error among observers of differing experience levels. The results of this work will be reported in future thesis products from A. Schaefer at the University of Montana.
- Type
- Published Report
- Authors
- Hoekman, Steven; Sergeant, Christopher; Johnson, William
- Date of Issue
- 2014-01
- Publisher
- National Park Service
- Units
- GLBA , NRSS , SEAN
- Keywords
- Abundance, Distance Sampling, Distribution, Glacier Bay, Kittlitz's Murrelet, Marbled Murrelet, Status, Summer, Trend
- Subjects
- Ecological Framework: Biological Integrity | Focal Species or Communities | Marine Communities , Ecological Framework: Biological Integrity | Focal Species or Communities | Birds , Ecological Framework: Biological Integrity | At-risk Biota | T&E Species and Communities