Accuracy of Depth Recorders
Accuracy of Depth Recorders
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DOI：
10.1675/063.032.0123
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发表时间：
2009-03-01
期刊：
影响因子：
0.3
通讯作者：
Gaston, Anthony J.
中科院分区：
文献类型：
--
作者：
Elliott, Kyle Hamish;Gaston, Anthony J.
Depth recorders are among the most useful tools available for ornithologists Interested in waterbird foraging behavior Despite their widespread use in the literature there is little information available about their precision and accuracy including for the case of TDRs device drift We examined the uncertainty associated nab two types of depth recorders deployed on Thick billed Muries Uria lomvia in the Canadian Arctic in 2007 for up to 48 hours The maximum depth obtained by capillary tube maximum depth gauges (MDGs) a cheap and simple depth recorder was highly col I elated (R-2 = 0 87) with maximum depth obtained by electronic time-depth recorders (TDRs) attached to the same bird (n = 29) up to depths of 100 in Deeper than 100 m or in deployments of 144 hours MDGs wet e unreliable We suggest that the maximum depth for Thick billed Murres in the Canadian Atcuc is about 150 in rather than the 210 meters previously reported using MDGs recorders and that caution should be used when quoting maximal maximum depths for species diving deeper than 100 m using this method We also attached two Lotek TDRs to the same bird (n = 18) and examined the similarity of the two recorders The average age difference increased from about 0 5 m near the surface to about 1 0 m below 60 m with extreme differences of up to 4 m obtained Furthermore TDRs submerged to known depth were accurate within +/- 2m The effect of these variations on measurements of maximum and average depth and duration was about 0 6-1 3 m (depth) or s (dura non) which is similar to the manufacturer s accuracy specifications (+/- 1%) Finally ne examined the drift (offset from zero at the surface) within the TDRs Drift varied from 2 5 to + 2 m with 9 out of 36 recorders showing no drift and no change amongst years for individual recorders Drift was lowest (most negative) at the colony higher during flight and highest (most positive) on the water surface despite very small differences in altitude (
