Bird Sightings at Sea

nature
fauna
pollar chart
column chart
Author

Ana Luisa Bodevan

Published

April 14, 2026

This week challenge dataset in on Bird Sightings at Sea. Check the TidyTuesday GitHub repo for the data.

1. SETUP

Code 
library(pacman)

pacman::p_load(
  tidytuesdayR,
  tidyverse,
  dplyr,
  janitor,
  scales,
  ggtext,
  showtext,
  glue,
  ggview
)

tuesdata <- tidytuesdayR::tt_load('2026-04-14')

beaufort_scale <- tuesdata$beaufort_scale |>
  janitor::clean_names()

ships <- tuesdata$ships |>
  janitor :: clean_names()

rm(tuesdata)

2. DATA ANALYSIS AND TIDYING

Code 
wind <- ships %>%
  left_join(beaufort_scale, by = "wind_speed_class") %>%
  filter(!is.na(wind_direction), !is.na(wind_speed_class)) %>%
  mutate(
    wind_description = fct_reorder(
      case_when(
        wind_description %in% c("calm", "light air") ~ "Calm",
        wind_description %in% c("light breeze", "gentle breeze") ~ "Light",
        wind_description %in% c("moderate breeze", "fresh breeze") ~ "Moderate",
        wind_description %in% c("strong breeze", "near gale") ~ "Strong",
        wind_description %in%
          c(
            "gale",
            "strong gale",
            "storm",
            "violent storm",
            "hurricane"
          ) ~ "Severe",
        TRUE ~ NA_character_
      ),
      wind_speed_class
    ),
    # Shift by 11.25 degrees so North is centered
    dir_binned = cut(
      (wind_direction + 11.25) %% 360,
      breaks = seq(0, 360, by = 22.5),
      labels = c(
        "N",
        "NNE",
        "NE",
        "ENE",
        "E",
        "ESE",
        "SE",
        "SSE",
        "S",
        "SSW",
        "SW",
        "WSW",
        "W",
        "WNW",
        "NW",
        "NNW"
      ),
      include.lowest = TRUE
    )
  )

summary_data <- wind %>%
  count(dir_binned, wind_description) %>%
  mutate(
    pct_total = n / sum(n) * 100
  )

3. PLOT

Code 
## colors

background_col <- "#f3f8f2" #FDFDFD",  #"#f5f5f2"
title_col <- "gray20"
subtitle_col <- "gray30"
text_col <- "gray30"

col <- c(
  "Calm" = "#cad2c5",
  "Light" = "#84a98c",
  "Moderate" = "#52796f",
  "Strong" = "#354f52",
  "Severe" = "#2f3e46"
)

## fonts

font_add_google("Nunito", "nunito")
showtext_auto()
showtext_opts(dpi = 300)

# title_font <- ""
# body_font <- ""

## text

title <- "**Bird Sightings at Sea**"
subtitle <- "Wind direction and intensity during seabird observation periods in NZ (1969 - 1990)"
caption <-
  "TidyTuesday 2026 Week 15 <br> **Source**: Museum of New Zealand Te Papa Tongarewa | **Graphic**: Ana Bodevan"
Code 
ggplot(
  summary_data,
  aes(x = dir_binned, y = pct_total, fill = wind_description)
) +
  geom_col() +

  # Allow full use of space
  coord_polar(start = -pi / 16, clip = "off") +

  scale_fill_manual(
    values = col
  ) +

  labs(
    title = title,
    subtitle = subtitle,
    caption = caption
  ) +

  theme_minimal(base_family = "nunito", base_size = 9) +

  theme(
    # Layout
    plot.title.position = "panel",
    plot.caption.position = "plot",
    plot.margin = margin(t = 10, r = 40, b = 10, l = 55),

    plot.title = ggtext::element_textbox_simple(
      size = rel(1),
      family = "nunito",
      halign = 0.5,
      width = unit(1, "npc"),
      margin = margin(t = 5, b = 8)
    ),

    plot.subtitle = ggtext::element_textbox_simple(
      size = rel(0.7),
      halign = 0.5,
      width = unit(0.9, "npc"),
      margin = margin(t = 6, b = 12)
    ),

    # Caption
    plot.caption = ggtext::element_textbox_simple(
      size = rel(0.5),
      halign = 0.5,
      margin = margin(t = 10, b = 20)
    ),

    # Background
    plot.background = element_rect(
      fill = background_col,
      colour = background_col
    ),
    panel.background = element_rect(
      fill = background_col,
      colour = background_col
    ),

    # Axis
    axis.text.y = element_blank(),
    axis.text.x = element_text(size = rel(1.1), face = "bold"),
    axis.title = element_blank(),

    # Legend
    legend.position = "right",
    legend.direction = "vertical",
    legend.title = element_blank(),
    legend.text = element_text(size = rel(0.5)),

    # Gridlines
    panel.grid.major = element_line(
      color = "#D0D7D8",
      linewidth = 0.075
    )
  )