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Rights Statements InC/1.0 , Open Access
Journal article
Long-term trend in marbled murrelets in Southeast Alaska based on Christmas Bird Counts
Northwest science., Vol.72(3), pp.170-179
1998
Handle:
https://hdl.handle.net/2376/1214
Abstract
A significant proportion of marbled murrelets (Brachyramphus marmoratus) occur in Southeast Alaska. We examined long-term trends in marbled murrelet abundance in this region by analyzing published Christmas Bird Counts (CBC) for 7 sites from 1971 to 1993. We analyzed records of murrelet counts and counts standardized by effort. Murrelet counts were highly variable, in particular, most sites recorded one or a few unusually high counts during the time series. Our exploration of trend using a battery of statistical analyses failed to provide evidence for a decline in marbled murrelets across the region for the period 1971-1993. In general, there was high concordance among sites when counts occurred in the same year (e.g. Kendall's W = 0.822, P = 0.0025 among 5 sites) which supports our argument that trends in murrelet abundance should be examined for the region as a whole rather than focusing on individual sites. Although our analyses provide little evidence for a sustained decline in marbled murrelets in Southeast Alaska, we suggest that our failure to detect a decline does not indicate that a decline has not occurred, only that CBC data does not support such a conclusion
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Details
- Title
- Long-term trend in marbled murrelets in Southeast Alaska based on Christmas Bird Counts
- Creators
- Gregory D. Hayward (Author)George C. Iverson (Author)
- Publication Details
- Northwest science., Vol.72(3), pp.170-179
- Academic Unit
- Northwest Science
- Publisher
- WSU Press
- Identifiers
- 99900502225501842
- Copyright
- In copyright ; openAccess ; http://rightsstatements.org/vocab/InC/1.0/ ; http://purl.org/eprint/accessRights/OpenAccess
- Language
- English
- Resource Type
- Journal article