Title: Life in Cold Blood
Author(s): David Attenborough
Release year: 2008
Publisher: BBC Books
Why in Database: Book version of the TV nature series with the same titlee. As in the TV version, a large part of the book is devoted to turtles, quite a solid, cross-sectional approximation. There is also a huge amount of pictures in the book, we do not show them all individually, but all in the form of one “collage”. There is also a lot of text about turtles – obviously, we cannot quote 1/4 of the book in the note, so we present only a few selected quotes.
The first fragment we chose is about gopher tortoises and the burrows they dig:
In hotter parts of the world tortoises have to defend themselves from the sun’s beat, especially during the middle of the day. A body enclosed within a thick shell can easily over-heat. That is a particular danger for the gopher tortoise (Gopherus polyphemus) which lives in Florida and other warm parts of south-east North America. It has broad strong claws on its front legs with which it digs so effectively that it can excavate a shaft three metres (10 feet) long in a single day. The work is extremely laborious, for the soil excavated from the far end of the tunnel has to be pushed all the way back and thrown out from the entrance. A completed burrow may extend for six metres (20 feet) or so. Exceptional ones have been measured that are twice that length. Most descend at a and gentle angle and go down until they reach the water table. it is. in these refuges that the gopher tortoises shelter during the hottest part of the day.
The second fragment we selected is about turtles longevity and how you can determine their age:
Tortoises, with their long scrawny necks and creaking deliberate gait, are often regarded as the very image of old age. And indeed they do live a very long time. The horny scutes on an individual’s carapace indicate its age in much the same way as do the rings in the trunk of a tree. They grow more quickly in the warm season than the cold, so each year they acquire a distinct ridge. Counting these ridges therefore can give an indication of a tortoise’s age. But as an individual gets older, so the ridges can become worn and blurred and in very old specimens accurate counts are not possible.
The next piece is about Tu’i Malila turtle, which is also described in another book we have in the database, Journeys to the Other Side of the World: further adventures of a young naturalist. It says, that this turtle may be the longest-lived turtle, according to available data, the punch line (apart from the quote already) is such that at the time of his death he probably was not as many years old as he was credited with:
A very ancient tortoise lived for many years in the roval palace on the Pacific island of Tonga. He was held in such respect and affection that he was given a name and a title. He was Tui — or Chief — Malila. He had certainly led a long and eventful life. He had been run over by a cart, kicked by a horse and scorched by several fires. His battered dented shell bore the scars to prove it. These disasters seemed to have done him little permanent harm but old age robbed him of his sight and towards the end of his life, he could no longer find his way to the flower-beds where he had browsed so happily and destructively in his earlier years. So every day he was handfed with ripe paw-paw and boiled mandioca. Tongan tradition maintained that he had been presented to the then King of Tonga by Captain Cook in either 1773 or 1777. He eventually died in 1966. If the tradition was correct, and he was reasonably grown when he arrived on the island, he must have lived for around two hundred years and. Tonga commemorated him by striking a coin carrying his image.
The next fragment is about the sizes that turtles can reach:
Tortoises, like many reptiles, may continue to grow throughout their lives, though the pace at which they do so tends to diminish the older they get and maximum size varies from species to species. Tui Malila, being a Madagascar radiated tortoise, was little more than 40 centimetres (16 inches) long. Marion’s tortoise, on the other hand, whose shell is now in London’s Natural History Museum, measures 97 centimetres (over 38 inches) for it was a genuine giant. It came from the Seychelles or perhaps Aldabra that lies far away from those islands to the south-west.
The penultimate fragment chosen by us is about the evolution of turtles, the opportunity that arose for them when the dinosaurs disappeared, and unfortunately the lost competition for domination with mammals:
Tortoises, when they first appeared over two hundred million years ago, were initially quite small. Perhaps it was the presence of the dinosaurs that kept them down to size. But when, sixty-five million years ago the dinosaurs disappeared, the lands of the earth were suddenly bereft of large animals. The tortoises had their chance and with little competing with them for food, they increased in size. Less than five million years ago there were some that reached 2 metres (6 feet) in length. But their supremacy did not last long. The mammals, in all their variety and ferocity, took over and eventually hunted the unwieldly giant tortoises to extinction.
But before that happened, the giants may have spread to islands in the Pacific and the Indian Ocean. Big tortoises can probably survive at sea even better than their smaller relatives. Their shells are proportionately thinner so they have a greater buoyancy and their long necks would help them keep their heads and nostrils above the waves, So it is possible that the ancestors of the giants of the Galapagos and the Seychelles were gigantic even before they reached the islands.
The last piece is something that could not be missing from the book about turtles, i.e. the recall of the Galapagos and the fact that turtles were one of the solid elements that led Charles Darwin to the formulation of his well-known theory:
When Charles Danvin visited the islands in 1835, the official British resident mentioned that he could tell which island a tortoise came from by the shape of its shell. It was this remark that thrimately led Darwin to formulate his theory of natural selection as the driving force of evolution.
Author: XYuriTT
