DOI: 10.5061/dryad.4f4qrfjnx
title: Data from: Alternative forms of brook trout nest site selection alter modeled offspring thermal experience and emergence phenology in groundwater-influenced streambeds

description: Although incubation temperature strongly influences salmonid phenotypic
 variation, few studies have considered the effect of competition on nest
 site selection and the resultant embryonic thermal experience. We combined
 field observations and simulations of brook trout spawning across a
 groundwater-induced thermal mosaic to assess whether habitat selection
 could alter spawning patch-level offspring thermal experience. We first
 assessed whether wild brook trout exhibited spawning behaviors consistent
 with competition for limited habitat. Given a fixed thermal habitat
 template, we then simulated offspring incubation temperature and
 temperature-dependent emergence timing following random, observed, and
 purely size-structured habitat selection scenarios. Brook trout generally
 selected warmer nest locations, but temperatures varied widely (1.8 –
 8.1°C) due in part to competition-related behaviors: minimum nest
 temperatures declined as breeder density increased, larger fish used
 warmer nests, and nest re-use frequency increased with nest temperature.
 Consequently, the three habitat selection scenarios generated biologically
 meaningful differences in simulated patch-level incubation temperatures
 and emergence dates. Studies evaluating the phenotypic and phenological
 consequences of incubation temperature may therefore benefit from
 considering alternative nesting behaviors that may substantially influence
 offspring thermal experience within populations.
description: # Alternative forms of brook trout nest site selection alter modeled
 offspring thermal experience and emergence phenology in
 groundwater-influenced streambeds
 [https://doi.org/10.5061/dryad.4f4qrfjnx](https://doi.org/10.5061/dryad.4f4qrfjnx) ## Description of the data and file structure These files provide 1) observational field data that relate the timing, body size, and competitive interactions of spawning female brook trout to the habitat variables of their used nests (streambed temperature), and 2) simulated data on the temperature-dependent emergence timing of offspring brook trout, based on modeled scenarios of alternative forms of brook trout nest site selection behavior. Datafile header descriptions are provided in the file "FritschieandCottinghamCJFAS_Metadata for all data files.xls". Some attributes contain empty cells that were not populated with NAs to minimize errors running scripts; the meaning of these empty cells or any NAs are provided for each relevant attribute in the metadata file. Observations occurred in October and November 2017 and 2018 in the Dead Diamond River, New Hampshire, USA.  The supplemental file cjfas-2024-0306suppla.pdf presents 6 supplemental analyses referenced in the main manuscript. Data and code for these analyses are included in the datasets described above and R scripts described below. ## Code/software R version 4.2.0 was used to generate two R files that analyze and simulate the provided data. The R file "FritschieCottingham_CJFAS_habitatselection_nocompetition.R" analyses simple habitat selection as a function of temperature and potential confounding factors (e.g., dissolved oxygen, substrate size, stream velocity and depth). The R file "FritschieCottingham_CJFAS_habitatselection_competition.R" further analyses potential evidence of competitive interactions driving habitat use patterns (e.g., superimposition, size-dependent nest site use) and provides a simulation modeling framework to evaluate differences in offspring outcomes (thermal experience, emergence timing) as a function of differences in nest site selection behavior. Both R scripts list the datafiles and R packages required to run them.