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USGS · 70187855

Population status of Kittlitz's and Marbled Murrelets and surveys for other marine bird and mammal species in the Kenai Fjords area, Alaska

Thomas I. van Pelt·John F. Piatt
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Abstract

The Kittlitz's murrelet ( Brachyramphus brevirostris ) is a rare seabird that nests in alpine terrain and generally forages near tidewater glaciers during the breeding season. More than 95% of the global population breeds in Alaska, with the remainder occurring in the Russian Far East. A global population estimate using best-available data in the early 1990s was 20,000 individuals. However, survey data from two core areas (Prince William Sound and Glacier Bay) suggest that populations have declined by 80-90% during the past 10-20 years. In response to these declines, a coalition of environmental groups petitioned the USFWS in May of 2001 to list the Kittlitz’s murrelet under the Endangered Species Act. In 2002, we began a three-year project to examine population status and trend of Kittlitz’s Murrelets in areas where distribution and abundance are poorly known. Here we report on the first field season, focused on the south coast of the Kenai Peninsula. We re-surveyed selected historical transects to evaluate trends, and surveyed new transects for improved population estimation during early July 2002. From a total of 66 Kittlitz’s Murrelets seen on transects, we estimate a total population of 509 Kittlitz’s Murrelets along the south coast of the Kenai Peninsula. Comparisons with past surveys suggest a decline of 83% since 1976, with an average rate of decline calculated as–6.9 % per annum. This decline is in agreement with population declines observed elsewhere in the species’ core glaciated range, indicating that steep population declines observed to date are likely to be a range-wide phenomenon. While the focus of the study was Kittlitz’s Murrelets, other species of marine birds and mammals were also surveyed. Populations of the closely related Marbled Murrelet appear to have increased during the same time period. The abundance and distribution of other species are presented in appendices.

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90° N90° S · 180° W ← longitude → 180° E
Source-reported bounding extent: 58.92733441827545° to 62.79493487887006° latitude; -153.3251953125° to -143.7890625° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

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Thomas I. van Pelt, John F. Piatt. 2003. Population status of Kittlitz's and Marbled Murrelets and surveys for other marine bird and mammal species in the Kenai Fjords area, Alaska. https://pubs.usgs.gov/publication/70187855

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