10-13-2017

Introduction

Data

library(tidyverse)
library(lubridate)
library(stringr)

us <- read_csv("scrubbed.csv.zip") %>%
  mutate(
    date_time    = mdy_hm(datetime),
    year_sighted = year(date_time)
  ) %>%
  filter(country == "us", year_sighted < 2014) # 2014 is incomplete

Sighting trends

Shapes over time