Colophon
The animals on the cover of Developing Web Apps with Haskell and Yesod, Second Edition are a common rhinoceros beetle (Xylotrupes ulysses) and an Apollo butterfly (Parnassius apollo).
Common rhinoceros beetles are famous for their size and unique head shape—the males possess a set of large horns, one pointing from the top of the head and another from the center of the thorax. These horns are used to fight other males for mating rights, and also to dig in search of food. The size of the horn relative to the body is a good indication of physical health and nutrition.
Male rhinoceros beetles can reach up to six inches in length, and this large size provides protection from most predators. However, these beetles cannot bite or sting, which makes them popular pets in some Asian countries. Their violent bids for female attention also make them widely used for gambling fights.
The Apollo butterfly is a beautiful white butterfly with black spots on the forewings and red eyespots on the hindwings. The size, placement, and shade of these spots can vary depending on the region the butterfly is from. This makes them a very attractive species to collectors, who endeavor to capture one of each variant.
These butterflies are native to Europe, and can be found as far east as central Asia. They prefer a habitat of mountain meadows that contain many nectar-providing flowers and rocky outcroppings for cocoon formation.
Due in part to over-collecting, but mostly to habitat loss, these butterflies are listed as “vulnerable” on the IUCN Red List. There are laws in place to restrict trade of individual Apollo butterflies, but more conservation needs to be done to prevent further loss of habitat. Climate change, acid rain, and urbanization are all contributing factors to the displacement of this species, but thankfully countries like Poland and Germany have small groups of conservationists working to protect their local populations.
Many of the animals on O’Reilly covers are endangered; all of them are important to the world. To learn more about how you can help, go to animals.oreilly.com.
The cover fonts are URW Typewriter and Guardian Sans. The text font is Adobe Minion Pro; the heading font is Adobe Myriad Condensed; and the code font is Dalton Maag’s Ubuntu Mono.