Data from: The impact of a range-shifting predator is affected by prey preference and composition
Data files
Jan 29, 2026 version files 194.09 KB
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Fig2Code.m
28.91 KB
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Fig2Data_DP.csv
1.66 KB
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Fig2Data_SR.csv
1.44 KB
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Fig3Code.m
40.90 KB
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Fig3Data_DP.csv
38.69 KB
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Fig3Data_SR.csv
5.92 KB
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Fig4Data.csv
48.71 KB
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FigA1Code.m
6.42 KB
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FigA1Data.csv
1.78 KB
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Figure4Code.m
14.14 KB
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README.md
5.52 KB
Abstract
Global biodiversity is undergoing a grand reshuffling with species across taxa and biomes shifting their ranges in response to climate change. Research on the ecological impacts of range-shifting species has prioritized linking the traits of the range-shifting species themselves to impacts, with studies giving more limited attention to the characteristics of the recipient community. Understanding how community composition and structure can alter the impact of novel species is important for predicting and managing ecological changes. We used the range-shifting predatory whelk Mexacanthina lugubris as a case study to investigate how the presence of shellfish prey might influence range shift impacts. We hypothesized that the structure of a recipient community would influence Mexacanthina lugubris’ consumptive effects. We tested this hypothesis via a field experiment in southern California, where we caged whelks at a gradient of densities and observed their predation on mussels, barnacles living on bare rock, and barnacles living on mussels over eight weeks. We found that Mexacanthina lugubris consumed barnacles on bare rock preferentially before consuming barnacles on mussels and mussels themselves. Our findings demonstrate that the composition and structure of the recipient community (i.e., the presence of mussels) can mitigate the overall impact of the range-shifting predator by altering prey accessibility. This context-dependent attenuation of predator effects highlights a form of apparent facilitation among prey and underscores the importance of considering recipient community traits when assessing or managing the ecological consequences of range-shifting species.
Kyle Suen
2025-06-26
The dataset consists of data gathered from caging experiments that were conducted to monitor the consumption of prey by a range-shifting predator. At Dana Point and Scripps Reef, CA, cages were placed at the intertidal zone on plots that contained California mussels and acorn barnacles. Varying densities of Mexacanthina lugubris, a range-shifting predatory whelk that feeds on mussels and barnacles, were placed in the cages. Observations were made of their feeding rates and prey preferences over the course of eight weeks in order to see how the presence of mussels may affect the feeding habits of barnacles by Mexacanthina lugubris. Results were displayed via consumption rates of barnacles on bare rock and of barnacles on mussels, and through changes in preference for barnacles on bare rock by Mexacanthina lugubris. Consumption rates of mussels were also recorded.
Description of the data and file structure
Datasets are split into different files that create corresponding figures for the manuscript.
1a. “Fig2Data_DP.csv” and “Fig2Data_SR.csv” contain the data for Figure 2, which shows changes in the percent cover of live barnacles as a function of the average number of Mexacanthina lugubris in cages over a time range of two, four, six, and eight weeks. The data shows the change in the percentage of barnacles on bare rock that are living (Change % Living Bare from Initial) and the change in percentage of barnacles on mussels that are living (Change % Living Mussel), categorized by the density of whelks that are in the cage and by time of observation. “Fig2Data_DP.csv” contains the data collected at Dana Point, and “Fig2Data_SR.csv” contains the data collected at Scripps Reef.
1b. “Fig2Code.m” contains the code for Figure 2. The code generates two sets of graphs that show changes in the percent cover of live barnacles as a function of the average number of Mexacanthina lugubris in cages over a time range of two, four, six, and eight weeks. Each set of graphs shows changes on different substrates (bare rock and mussels), indicated by different colored lines, and at different sites (Dana Point and Scripps Reef).
2a. “Fig3Data_DP.csv” and “Fig3Data_SR.csv” contain the data for Figure 3, which shows changes in Mexacanthina lugubris preference for barnacles on bare rock compared to barnacles on mussels as a function of the average number of Mexacanthina lugubris in cages over a time range of two, four, six, and eight weeks. Preference is quantified through the selectivity index Chesson’s Alpha. Columns A-J in both datasets contain observation data gathered from the aforementioned caging experiment. Columns K-AD contain the calculations done to find the selectivity index for the observation data, with columns AA and AB showing Chesson’s Alpha for Barnacles on Mussels and Chesson’s Alpha for Barnacles on Bare Rock, respectively. “Fig3Data_DP.csv” contains the data collected at Dana Point, and “Fig3Data_SR.csv” contains the data collected at Scripps Reef.
2b. “Fig3Code.m” contains the code for Figure 3. The code generates two sets of graphs that show changes in Mexacanthina lugubris preference for barnacles on bare rock compared to barnacles on mussels as a function of the average number of Mexacanthina lugubris in cages over a time range of two, four, six, and eight weeks. Each set of graphs shows changes at different sites (Dana Point and Scripps Reef).
3a. Fig4Data.csv contains the data for Figure 4, which shows changes in the number of live mussels in a plot as a function of the average number of Mexacanthina lugubris over a time range of two, four, six, and eight weeks. Live mussels are listed in a column, categorized by the density of whelks that are in the cage, by time of observation, and by site. Note: In the table, values do not start until Row 58. The data for this figure and set of results comes from a larger dataset gathered from the lab on intertidal communities as a whole. As the figure only needed information on California Mussels, all other data were omitted. Other rows were not deleted as the code was set to gather data based on the original row number.
3b. “Figure4Code.m” contains the code for Figure 4. The code generates two sets of graphs that show the number of live mussels via consumption as a function of the average number of Mexacanthina lugubris in cages over two, four, six, and eight weeks. Each set of graphs shows changes at different sites (Dana Point and Scripps Reef).
4a. “FigA1Data.csv” contains the data for Figure A1 in Appendix 1, which shows the percent cover of live and dead barnacles on mussels within each plot at Dana Point and at Scripps Reef. The percent cover of barnacles on mussels is split into two columns: alive and dead. Columns are categorized by whether the observation was conducted in the field or via a photo and by site.
4b. “FigA1Code.m” contains the code for Figure A1. The code generates two bar graphs that show the percent cover of live and dead barnacles on mussels within each plot at Dana Point and at Scripps Reef. Bars are colored depending on whether the data was gathered from an observation of a photograph taken at the site or from an on-site observation.