DOI: 10.5061/dryad.s7h44j1g0
title: Data and code from: Prey detection by a stepwise visual template matching mechanism

description: Prey capture success by a predator can be improved by the formation of a
 search image, and recent experience with a prey item provides a visual
 template to which subsequent potential prey are compared. Following
 observations of distinct trout feeding responses to drifting mayflies in a
 large western U.S. river in the same month across two successive years, we
 developed a set of experiments to test if changing ratios of sequentially
 delivered prey of the same species but different body sizes caused a shift
 in trout feeding response. We discovered that large-sized focal prey were
 always consumed. Comparing predation on large- versus small-sized prey
 (137% length difference), few small prey were consumed, but when comparing
 large- versus medium-sized prey (99% length difference), all medium prey
 were consumed. When small-sized prey, initially rejected, were compared
 with the newly established medium-sized focal prey (57% length
 difference), all medium and small prey were consumed. When trout
 previously exposed to small prey were subsequently fed only large prey,
 fish memory of the small prey lasted for at least 14 days. These results
 provide evidence that predator search image formation for novel prey
 requires a dynamic stepwise neural template matching process. We discuss
 how this mechanism could be used by many consumers to optimize foraging,
 with implications for predator and prey population dynamics, such as the
 persistence of rare prey and its role in selection on prey phenology to
 minimizes predation of different size classes, species, or both.
description: **Data and code for prey detection by a stepwise visual template matching
 mechanism**
 [https://doi.org/10.5061/dryad.s7h44j1g0](https://doi.org/10.5061/dryad.s7h44j1g0) GENERAL INFORMATION 1. Title of Dataset: Data and code for prey detection by a stepwise visual template matching mechanism. 2. Author Information A. Principal Investigator Contact Information Name: Brad Taylor. Institution: North Carolina State University. Address: Raleigh, NC USA. Email: [bwtaylo3@ncsu.edu](mailto:bwtaylo3@ncsu.edu). B. Associate or Co-investigator Contact Information Name: Jules Silverman. Institution: North Carolina State University. Address: Raleigh, NC USA. Email: [jsilver@ncsu.edu](http://jsilver@ncsu.edu). 3. Date of data collection (single date, range, approximate date): 2012-2013 4. Geographic location of data collection: Raleigh, North Carolina 5. Information about funding sources that supported the collection of the data: National Science Foundation and JS funds. SHARING/ACCESS INFORMATION 1. Licenses/restrictions placed on the data: CC0 1.0 Universal (CC0 1.0) Public Domain 2. Links to publications that cite or use the data: Silverman, J. and Taylor, B.W. (2023). Data and code for prey detection by a stepwise visual template matching mechanism. TBD_XXXX. 1. Links to other publicly accessible locations of the data: None 2. Links/relationships to ancillary data sets: None 3. Was data derived from another source? No A. If yes, list source(s): NA 4. Recommended citation for this dataset: Taylor, B.W. and J. Silverman. (2023).** Data and code for prey detection by a stepwise visual template matching mechanism. [https://doi.org/10.5061/dryad.s7h44j1g0](https://doi.org/10.5061/dryad.s7h44j1g0) DATA & FILE OVERVIEW 1. File List: 1) ExposureRatioCode.sas 2) ExposureRatioData.csv 3) ExposureRatioMetaData.csv D) ExtralargePreyExpCode.sas E) ExtralargePreyExpData.csv F) ExtralargePreyExpMetaData.csv G) SmallPreyMemoryExpCode.sas H) SmallPreyMemoryExpData.csv I) SmallPreyMemoryExpMetaData.csv J) readme.md (this file) 1. Relationship between files, if important: Files ending in .SAS are the SAS code; files ending in .csv are either data or metadata files, as indicated in the filename. 2. Additional related data collected that was not included in the current data package: None 3. Are there multiple versions of the dataset? No A. If yes, name of file(s) that was updated: NA 1. Why was the file updated? NA 2. ii. When was the file updated? NA GENERAL OVERVIEW AND DESCRIPTION OF THE STUDY The data and code are for a series of experiments testing brown trout feeding responses to different ratios of prey that differ in size to assess if prey frequency, size, both, or other mechanisms are used by trout to assess suitable prey. A series of three experiments tested how trout feeding responded to increasing the exposure ratio of large focal to small novel prey, and the size difference between focal and novel prey was reduced among the three experiments. Another experiment tested brown trout feeding responses to prey larger than the large focal prey. The aim was to assess whether brown trout use absolute size of prey or learning and prey matching to a neural template. The last experiment tested brown trout memory of prey by exposing trout to small prey, withholding this size prey and feeding trout other prey sizes, then exposing trout to small prey. \######################################################################### DATA-SPECIFIC INFORMATION FOR: ExposureRatioData.csv 1. Number of variables: 12 2. Number of cases/rows: 163 including one row of column names 3. Variable List: see ExposureRatioMetaData.csv 4. Missing data codes: NA = fish did not consume prey within 300 sec trial time period, or values could not be calculated because no prey were consumed or division by zero. 5. Specialized formats or other abbreviations used: see ExposureRatioMetaData.csv \######################################################################### DATA-SPECIFIC INFORMATION FOR: ExtralargePreyExpData.csv 1. Number of variables: 6 2. Number of cases/rows: 29 including one row of column names 3. Variable List: ExtralargePreyExpMetaData.csv 4. Missing data codes: NA or "." = fish did not consume prey within 300 sec trial time period 5. Specialized formats or other abbreviations used: see ExtralargePreyExpMetaData.csv \######################################################################### DATA-SPECIFIC INFORMATION FOR: SmallPreyMemoryExpData.csv 1. Number of variables: 7 2. Number of cases/rows: 37 including one row of column names 3. Variable List: see SmallPreyMemoryExpMetaData.csv 4. Missing data codes: NA 5. Specialized formats or other abbreviations used: see SmallPreyMemoryExpMetaData.csv \######################################################################### CODE-SPECIFIC INFORMATION FOR: ExposureRatioCode.sas This is the SAS code used to organize and process the raw data and calculate means for each exposure ratio across the six fish and three experiments with different sizes of focal and novel prey. Data files used by this code: ExposureRatioData.csv \######################################################################### CODE-SPECIFIC INFORMATION FOR: ExtralargePreyExpCode.sas. This is the SAS code used to organize and process the raw data, calculate means for the response across the six fish to the extralarge prey as the novel prey, and test for changes in prey consumption and time to consumption over successive days. Data files used by this code: ExtralargePreyExpData.csv \######################################################################### CODE-SPECIFIC INFORMATION FOR: SmallPreyMemoryExpCode.sas This is the SAS code used to organize and process the raw data, calculate means for the response across the six fish to the small prey, and test for changes in prey consumption and time to consumption after small were withheld from fish for 7 days, then delivered to the fish on days 8-14. Data files used by this code: SmallPreyMemoryExpData.csv \######################################################################### END OF README FILE