Data from: predator-induced defences under tropicalisation: a biogeographic approach
Data files
Sep 15, 2023 version files 251.75 KB
Abstract
Aim: The biogeography of predator-induced defences is an understudied area of predator-prey dynamics. Range overlap with predators that induce the response and local demographics (e.g., prey abundances) are likely to be important factors for determining the biogeographic distribution of induced defences within species. However, with climate warming, range expanding warm-water predators are increasingly preying upon temperate species. This is a consequence of a wider phenomenon known as tropicalisation. We aim to determine: (i) if individuals of a temperate barnacle with induced defences (“bent morphs”) are primarily present where they co-occur with range-expanding warm-water predators (muricid snails) and, (ii) if bent morphs are size-structured within populations.
Location: North-eastern Pacific rocky intertidal zone (~26-40ºN)
Taxon: Tetraclita rubescens (Nilsson-Cantell, 1931), Balanomorpha
Methods: We use photo quadrats from sites across the range of T. rubescens to determine the biogeographic distribution of populations with bent morphs and to assess size-structure. We use a combination of field surveys, literature, and museum occurrences to assess range overlap between cool and warm-water predators of T. rubescens and their association with populations with bent morphs and abundance patterns of T. rubescens.
Results: Bent morphs are commonly found within the equatorward portion of the species’ range (where abundances are highest), in populations overlapping with range expanding warm-water predators. Bent morphs primarily occur within the smaller size classes.
Main conclusions: To be partly resilient to the effects of tropicalisation, temperate prey must acclimatize/adapt to altered predator-prey dynamics. Predator-induced defences are one way to do this. We show that bent morphs within a temperate prey species (T. rubescens) are largely restricted to populations that overlap with large-bodied and range-expanding warm-water predators. This is evidence for the partial resilience of T. rubescens to tropicalisation and provides the rationale for further exploration of the eco-evolutionary consequences of tropicalisation in this study system and others.
README: Predator-induced defences under tropicalisation: a biogeographic approach
Authors:
Phillip B. Fenberg, Rodrigo Beas-Luna, Boris Igi, Moira A. MacLean, David A. Paz-Garca, Peter T. Raimondi, Jacqueline L. Sones, Karolina M. Zarzyczny, Eric Sanford
Description of the data and file structure
The datasets are in a single excel file with five sheets. Each sheet is clearly labelled beginning with which figure the data are from (Fig 3, 4, and 5).
The data in sheet Fig_3_data_iNat come from iNaturalist. Each cell represents a single iNaturalist photograph arranged by latitude. No bent morphs were found in these records.
The data in sheet Fig_4_data contains the size-frequency data used in Fig. 4 for each site. Individual basal shell diameters (mm) in column A, Morph (conic or bent) in column B, and site in Column C.
The data in sheet Fig_5_data_abundance have the abundance data (expressed as % cover; column B) versus Latitude (column A). These data are from field surveys undertaken by MARINe (https://marine.ucsc.edu/index.html).
The data in sheet Fig_5_muricid_ranges are the geographic range data for each predator known to feed on T. rubescens are in columns H-L.
More information about methodology used to obtain all data can be found in the main paper and the supplementary file.
Methods
The datasets come from analysis of photo quadrats taken in the field from sites spread across the geographic range of Tetraclita rubescens. Size data of each barnacle and morph were taken using the software programme ImageJ. We also used occurrence records from iNaturalist to supplement our datasets. The methods section of the paper provides more detail.