Day 5 of 30DayMapChallenge: « A Journey » (previously).
Thirteen Blue whales (Balaenoptera musculus) 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)
unzip("AAS_4101_pygmy_blue_whale_SSSM.zip",
files = "bw_3h_ssm.RDS")
bm <- read_rds("bw_3h_ssm.RDS")
# str(bm)
journeys <- bm$summary |>
st_as_sf(coords = c("lon", "lat"), crs = "EPSG:4326") |>
group_by(id) |>
arrange(date) |>
summarise(do_union = FALSE) %>%
st_cast("LINESTRING") |>
group_by(indiv = as.factor(parse_number(as.character(id)))) |>
summarise()
After joining GPS points as lines and lines from the same whale as multilines, we can use {leaflet} for an interactive map.
pal <- colorFactor("viridis", sort(unique(journeys$indiv)))
journeys |>
leaflet() |>
addTiles() |>
addPolylines(color = ~ pal(indiv),
popup = ~ indiv) |>
addLegend(pal = pal,
values = sort(unique(journeys$indiv)))