Monitoring Kittlitz’s and marbled murrelets in Glacier Bay National Park and Preserve: 2015 annual report
Sergeant CJ, Hoekman ST, Johnson WF. 2015. Monitoring Kittlitz’s and marbled murrelets in Glacier Bay National Park and Preserve: 2015 annual report. Natural Resource Report. NPS/SEAN/NRR—2015/1076. National Park Service. Fort Collins, Colorado
Annual abundance and spatial distribution surveys of murrelets in Glacier Bay (Year 7). Since 2009, the National Park Service’s Southeast Alaska Inventory and Monitoring Network (SEAN) has monitored population abundance and spatial distribution of Kittlitz's (KIMU) and marbled murrelets (MAMU) in Glacier Bay National Park and Preserve, an important summer residence for both species. Monitoring program design focuses on KIMU, with secondary consideration of MAMU. 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 249.9 km on 46 transects from 9-16 July 2015 across the 1,170 km2 survey area in Glacier Bay proper. We estimated an abundance of 10,778 KIMU (SE = 2,598) and 83,793 MAMU (SE = 12,044). Estimated KIMU abundance was slightly lower than the seven-year average of abundance estimates (11,255) and increased only 3% from 2014. Estimated MAMU abundance was the second highest on record and increased 102% from 2014. From 2009 to 2015, 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 (seven-year average = 60,959) with annual changes of -51% 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.
- Type
- Published Report
- Authors
- Sergeant, Christopher; Hoekman, Steven; Johnson, William
- Date of Issue
- 2015-11
- Publisher
- National Park Service
- Units
- GLBA , NRSS , SEAN
- Keywords
- Brachyramphus, distance surveys, Kittlitz's Murrelet, Line transects, Marbled Murrelet, marine ecosystem, pelagic
- Subjects
- Ecological Framework: Biological Integrity | Focal Species or Communities | Marine Communities , Ecological Framework: Biological Integrity | Focal Species or Communities | Birds