In her book, Where Have All the Bees Gone?: Pollinators in Crisis, from the eBook High School Collection, Rebecca Hirsh points out that more than twenty thousand species of bees live around the world. Globally, bees pollinate about $24 billion worth of crops—almost 10 percent of the total value of food production worldwide. Due to pesticides, development, and the elimination of certain plant species, bee populations are in rapid decline. In her most recent (2022) publication, Where Have All the Birds Gone?: Nature in Crisis, she references a 2019 study published in the journal, Science: Since 1970, 3 billion birds—nearly 30 per cent of all the birds in the United States and Canada—had vanished. Finally, in her book, The Monarchs Are Missing: A Butterfly Mystery , readers learn that between deforestation in Mexico and temperature changes in Texas, the Monarch Butterfly population is facing serious challenges.