DOI: 10.5281/zenodo.14563511
title: Growth dynamics of bottlenose dolphins (Tursiops truncatus) at the southern extreme of their range

description: Version release associated with GitHub repository: https://github.com/leahcrowe-otago/FBD_measurements/tree/main



This repository is associated with the following publication:

Crowe LM, Schofield MR, Dawson SM, Rayment WJ (2025) Growth dynamics of bottlenose dolphins (\textit{Tursiops truncatus}) at the southern extreme of their range. Marine Ecology Progress Series https://doi.org/10.3354/meps14858

Poster presented at the 2024 Society for Marine Mammalogy conference: Crowe LM, Schofield MR, Dawson SM, Rayment WJ (Nov 2024). Growth estimates of bottlenose dolphins (Tursiops truncatus) at the southern extreme of their range. Poster presentation at the 25th Biennial Conference on the Biology of Marine Mammals, Perth, Western Australia, Australia.



Workflow:




Identify when in video dolphin surfaces, ID that dolphin

Screen grab the best image of the dolphin above that shows rostrum to tail at/near the surface




used VLC player to go frame by frame




Add screen grab filename to the time and ID from #1

Run "./scripts/Altitudes for snapshots" for each day of droning




this adds a check to make sure GPS of the LiDAR and the metadata from the drone match up

finds altitude for each snapshot

matches up to IDs and outputs file to enter measurements

identifies if altimeter reading meets criteria per Dickson et al. 2020 ("issues" column)




Populate the "altperimage_*" file with measurements (.csvs from Whalelength are later merged in "./scripts/whalength_file_merge.R")




filter by issue == "N"

hide columns C, G, H, and J to AC

Run each resulting image through Whalength



I1P Video stills, -1.5 cm offset






Run "measurements_demo.Rmd" to wrangle data, incorporate life history info ("demo"graphy data), and create some supplementary figures




calls "whalength_file_merge.R"



merges all Whalelength outputs

creates Fig. S4, calibration measurements



Supplementary Figures S5

data output: see data repo for metadata details



individual i measurement data at each capture occasion j for model

individual life history data






Model run in the "./scripts/stan/runstan_allo_mv_t0.R" file: 'run' the 'stan' code of 'allo'metric measurement data in a 'm'ulti'v'ariate model with fixed age at length zero (t0)




data formatting for model

calls the Stan model



main model: "./scripts/stan/vb_mod_all0_t0.stan"

for the supplementary sex/pod effect model: "./scripts/stan/sex_pod_effects.R" runs the model specified in "./scripts/stan/vb_mod_all0_t0_sexpod.stan"



initial values for von Bertalanffy model (init_vb)

fit the model (fit_vb)

save results




"./scripts/Results.R"




read data

summarise results

create table S2

create Figs. 2–4, S6, S7




"Supplementary.qmd" creates the suppmat file




creates supplementary tables

Section 1.3 created from './scripts/Results_age_adjusted.R'

Fig. S1 map created by calling "./scripts/ms_map.R"




Data: "./data/Measurements/Data for review"




Metadata-description.pdf: describes the data in the following files:



i_estimates.csv

ij_1.csv

ij_2.csv

ij_3.csv

ij_ID.csv

mcmc_results.csv