Survivors in Armor: Turtles, Tortoises, and Terrapins

Dr. Patrick W. Colgan is Director of Research and Natural Lands at the
Royal Botanical Gardens.

Turtles (including tortoises and terrapins) are an old, heterogeneous,
and fascinating group of some 300 living species worldwide. This
splendid book begins with that central feature, the shell, and its many
consequences for growth, structure, and functions such as breathing. An
evolutionary perspective of 220 million years includes the earliest
known (Proganochelys), the largest (the five-metre Cretaceous Archelon),
fossil ninja species, the re-invasion of the oceans, and new
relationships based on cladistic analysis. A review of contemporary
species includes the weird matamata, smelly musk turtles, and the
reduced shell of leatherbacks. Their distribution nicely reveals the
impact of continental drift. In terms of human impact, one Bangladesh
species is protected by association with an Islamic saint, while a less
fortunate Venezuelan one is a Christian Holy Week delicacy.

Physiology is well explored in terms of temperature adaptations, salt
balance, underwater breathing, and the warm-bloodedness of leatherbacks
via countercurrent circulation. General features of life history include
longevity, orientation, ecological aspects, and feeding. Reproduction is
well presented, with attention to issues such as the bright coloration
of hatchlings and the impact of environmental warming for species whose
sex is determined by temperature. The material on migrations of marine
turtles shows how these are not fully understood despite ambitious
tracking work. The final chapters on conservation address global
anthropogenic devastation from exploitation and loss of habitat. The
impact of the pet trade, conservation efforts through both international
conventions and fieldwork, and the controversy over exclusion devices
for shrimp trawlers are all laudably emphasized. Lonesome George, the
last of his race from the Galapagan island of Pinta, is a sad symbol.

The easy conversational flow of the detailed text, spiced with humorous
anecdotes, makes for smooth reading. The many color photographs richly
illuminate the diversity and beauty of this group: those of wormlike
tongue decoys and eye-spot markings are especially impressive. A few
items would have benefited from greater explication, and a spell check
and scrutiny would have avoided some peccadilloes including caption
errors and, ironically, an error in the section “A Word About
Words.” It is a pity that the full bibliography is available only on
the Internet.