Research
Interim
Report
Feb 1998
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Interim
Report
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More
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Marbled Murrelets
PNW
Funded Projects
2001
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1999
1998
1997
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1995
PNW Project Overview 1999
Development of Radar as a Tool to Increase the Efficiency and Accuracy of the Marbled Murrelet Inland Forest Survey Protocol (IFSP)
Principal
Investigator:
Brian Cooper, ABR,
Inc.
Awarded: $42,000
Project
Description:
The
goal of the study is to conduct a second year of research to develop and
test radar techniques to improve the efficiency and accuracy of the Inland
Forest Survey Protocol (IFSP) for Marbled Murrelets. Specifically, the
project will compare radar and audio-visual techniques and address the
following null hypothesis: There is no difference between radar methods
and standard audio-visual methods in number of days needed to detect
presence of murrelets in a stand. Previous radar studies funded by ONRC
during 1997-1998 found that many more murrelets were detected by radar
than by audio-visual observers. In fact, there were several days when
radar detected murrelets and audio-visual observers did not detect any
murrelets.
These results suggested that radar could be used to improve the
efficiency of the survey protocol by more quickly and more accurately
determining the presence or absence of birds (especially at low-use
sites). If these radar techniques were found to improve the current survey
protocol, results from this study would provide land managers with a tool
to more accurately, more quickly, and less expensively assess murrelet
presence in a stand.
Project Status:
ABR, Inc. expects to
submit a manuscript for review by July 2001.
Preliminary
Results:
ABR,
Inc. examined 50 of the Washington State Department of Natural Resources
murrelet survey stands in the northwestern Olympic Peninsula to assess
their suitability for radar-based observations.
Fourteen of these sites were used for radar sampling.
Most of the sites consisted of an isolated old-growth stand that
was surrounded by a clearcut or by young trees.
Concurrent radar and audio-visual observations that followed the
Pacific Seabird Group
(PSG) protocol were made from early May through July
on 44 mornings in 1998 and 43 mornings in 1999.
The study supported by ONRC in 1996 and 1997 (Cooper and Blaha, 1998) focused on the numerical relationship between the number of Marbled Murrelets observed on radar and the number of murrelets that were detected audio-visually, whereas this study compared the ability of the two techniques to determine the presence of murrelets. It is important to make these comparisons because, when actual IFSP surveys are conducted, it takes only one survey on which at least one bird was seen or heard to classify the site as having murrelets “present.” In 1999, murrelets were detected 100% of the days with radar; thus, the mean number of days required to determine “presence” with radar was 1.0. The number of days required to determine “presence” with the audio-visual technique was significantly higher, ranging from 1 to over 5 days, with a mean of greater than 2.3 days. Thus, preliminary results indicate that a lift-assisted radar is a powerful tool for more quickly determining the “presence” of murrelets at a stand than the standard audio-visual technique.
