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Historical comparisons of body size are sensitive to data availability and ecological context.

Authors :
Elahi R
Miller LP
Litvin SY
Source :
Ecology [Ecology] 2020 Sep; Vol. 101 (9), pp. e03101. Date of Electronic Publication: 2020 Jun 26.
Publication Year :
2020

Abstract

Historical comparisons of body size often lack pertinent details, including information on the sampling protocol and relevant ecological covariates that influence body size. Moreover, historical estimates of body size that rely on museum specimens may be biased towards larger size classes because of collector preferences, and thus size thresholds have been used to focus attention on maximum body size. We tested the consequences of sampling design, ecological covariates, and size thresholds on inferences of body-size change using field-contextualized historical records, rather than museum specimens. In 2014-2015, we revisited historical (1947-1963) size-frequency distributions of three gastropods (Tegula funebralis, Lottia digitalis/L. austrodigitalis, Littorina keenae) in the context of population density and tidal height. In general, gastropods declined in size. However, our inferences regarding body-size decline were tempered when the variation between sampling units was taken into consideration, resulting in greater uncertainty around the estimate of proportional change in body size. Gastropod size was correlated with population density and tidal height, and these relationships varied over time. Finally, the magnitude and direction of body-size change varied with the amount of data available for analysis, demonstrating that the use of size thresholds can lead to incomplete conclusions.<br /> (© 2020 by the Ecological Society of America.)

Details

Language :
English
ISSN :
1939-9170
Volume :
101
Issue :
9
Database :
MEDLINE
Journal :
Ecology
Publication Type :
Academic Journal
Accession number :
32455494
Full Text :
https://doi.org/10.1002/ecy.3101