Day 5 of 30DayMapChallenge: « A Journey » (previously).
Thirteen Blue whales (Balaenoptera musculus L.) were satellite tagged in 2015 in Australia (Mӧller et al. 2020). We’ll follow their summer in the Great Southern Australian Coastal Upwelling System (GSACUS).
Data is available from the Australian Antarctic Data Centre (Andrews-Goff et al. 2020), directly as a R RDS file.
library(dplyr)
library(readr)
library(sf)
library(leaflet)
library(glue)
unzip("AAS_4101_pygmy_blue_whale_SSSM.zip",
files = "bw_3h_ssm.RDS")
bm <- read_rds("bw_3h_ssm.RDS")
# str(bm)
journeys <- bm$summary |>
st_as_sf(coords = c("lon", "lat"), crs = "EPSG:4326") |>
group_by(id) |>
arrange(date) |>
summarise(do_union = FALSE,
d_min = min(date),
d_max = max(date)) %>%
st_cast("LINESTRING") |>
group_by(indiv = as.factor(parse_number(as.character(id)))) |>
summarise(d_min = as.Date(min(d_min)),
d_max = as.Date(max(d_max)))After joining GPS points as lines and lines from the same whale as multilines, we can use {leaflet} for an interactive map.
pal <- colorFactor("viridis", sort(unique(journeys$indiv)))
journeys |>
leaflet() |>
addTiles() |>
addPolylines(color = ~ pal(indiv),
popup = ~ glue("<b>{indiv}</b><br />
from {d_min} to {d_max}")) |>
addLegend(pal = pal,
title = "Whales ID",
values = sort(unique(journeys$indiv)))
References
Andrews-Goff, Virginia, Mike Double, Luciana Möller, Catherine Attard, Kerstin Bilgmann, Ian Jonsen, and Dave Paton. 2020. “Switching State Space Model for Pygmy Blue Whale Satellite Tag Derived Locations.” Australian Antarctic Data Centre. https://doi.org/10.26179/5E671120E52B4.
Mӧller, Luciana M., Catherine R. M. Attard, Kerstin Bilgmann, Virginia Andrews-Goff, Ian Jonsen, David Paton, and Michael C. Double. 2020. “Movements and Behaviour of Blue Whales Satellite Tagged in an Australian Upwelling System.” Scientific Reports 10 (1): 21165. https://doi.org/10.1038/s41598-020-78143-2.