Hummingbirds are apparently the most popular birds in North America, and reading these two appealing books about them makes it easy to understand why. Any account of hummingbirds deals in amazing statistics: their wings beat between 50 and 200 times a second, they must eat half their weight in food each day, and some of them migrate over 3,200 kilometres from north to south and back again every year. Swanson notes that “one blue-throated hummingbird nest, used for 10 years, contained 24,000 kilometres (15,000 miles) of spider silk,” and Aziz records the journey of a rufous hummingbird who covered “750 miles (1,200 km) in 15 days and even gained weight during the trip.” Beautiful colour photos in both books give a sense of the diversity of the species, the brilliance of their plumage, and their diminutive charm.
While dealing with basically the same subject matter, and similar in size and external appearance, these two non-fiction books are aimed at different audiences. In her 22nd title in the Welcome to the World series, Swanson, an award-winning nature writer, makes her material accessible and appealing to fairly young readers, with large print, sidebars, and many photos. Aziz provides much more detail, depth, and breadth of coverage, in a format that is also generously illustrated and attractively presented. Her book is a more useful resource for upper elementary grades, and older readers too, who can handle the relatively complex language, careful explanations, and use of scientific terms (usually clarified in context). A reader who takes in all Aziz has to say about hummingbirds, and their place in nature and human society, will have learned a lot about biology and ecology along the way.
In helping children grasp the meaning of statistics, comparisons are helpful, and both authors use them effectively: Swanson points out that a man who used as much energy as a ruby-throated hummingbird does would need to eat 130 kilograms (285 pounds) of hamburger every day, and Aziz compares the hummingbird’s torpor to a computer’s sleep mode. Both writers describe the vulnerability of hummingbirds, and the hazards that beset them, without being alarmist. The photos in both books are strikingly beautiful. Aziz also discusses hummingbird feeders, and how to place and maintain them – an element Swanson might have included too, given the popularity of backyard feeders.