Life in Cold Blood Quotes

“Both chi-chaks and tokays have discovered that the lights used at night by human beings in their houses attract great numbers of flying insects, so they establish their territories nearby, quite unconcerned by the presence of people a few yards away. Often a single gecko will claim the entire area illuminated on the ceiling by a bulb and aggressively chase away any other that dares to venture on to it. The tokay repeats its two-syllable call about half a dozen times and then ends each sequence with a low gargle. The number of repetitions, however, varies and the local people, who are often dedicated gamblers, will sit late into the night placing extravagant bets on how many times a male will next repeat himself.”
― David Attenborough, Life in Cold Blood

“The tuatara's most efficient operating temperature seems to be around 12 degrees C. At such low temperatures, the chemistry of an animal's body works very slowly indeed and in consequence, the tuatara has a very lethargic life style. It only breathes about once every seven seconds, even when active, and when resting it may go for an hour without breathing at all. It takes about twenty years to grow to maturity. A female, having started to develop her eggs within her oviduct, needs four years to complete them. Even wrapping a shell around them, which a bird manages in a matter of a few hours, takes her six to eight months. And once her eggs have been laid, they take about fourteen months to hatch-the longest embryonic development of any reptile. Such is life in the slow lane. On the other hand, it is thought that tuataras may live for as much as a hundred and twenty years or more-and that is longer than any known lizard.”
― David Attenborough, Life in Cold Blood

“The rattlesnake represents the very acme of serpentine sophistication. It has superlative sensing organs that exploit infra-red and chemo-sensory stimuli to enable it to locate its prey. It is armed with one of the most powerful of all venoms with which it can inject its victims with surgical precision. It is long-lived and produces its young fully formed and immediately capable of fending for themselves.
But it has one vulnerability, one way in which human beings who see rattlesnakes as a threat to their own dominance are able to attack it. In North America, in the northern part of the rattlesnake’s range, winters can be so severe that a cold-blooded snake cannot remain active. So many species that are common elsewhere in North America do not spread far north. Rattlers are among the few that do. They survive the winter by another special adaptation. They have developed the ability to hibernate.
On the prairies of the mid-West and north into Canada, they choose to do so in the burrows of prairie dogs, rodents related to marmots. Elsewhere in the woodlands, they find outcrops of rocks that are riven by deep clefts. But such places are not abundant. As autumn approaches and temperatures fall, great numbers of rattlesnakes set out on long cross-country journeys of many miles following traditional routes to the places where they and their parents before them hibernate each year. Some of these wintering dens may contain a thousand individuals. So those human beings who hate snakes and who, in spite of the rattler’s sophisticated early warning system, believe that they are a constant and lethal threat, are also able, at this season of the year, to massacre rattlesnakes in thousands.
As a consequence one of the most advanced and wonderfully sophisticated of all snakes — perhaps of all reptiles — is now, in many parts of the territories it once ruled, in real danger of extinction.”
― David Attenborough, Life in Cold Blood

“The most elaborate way of delivering venom has been evolved by yet another family of snakes, the vipers. These include, as well as several different species of viper, such feared creatures as the bushmaster, the fer-de-lance, puff adders and rattlesnakes. The fangs of a king cobra are little more than a centimetre in length. The Gaboon viper (Bitis gabonica), by contrast, which is less than a third of the king cobra’s size, has fangs four times longer. They are so big that if they were fixed in their sockets the snake would be unable to shut its mouth. But they have hinges at their base so that they can fold back and lie, each sheathed in a scabbard of mucous membranes, along the roof of the mouth. Furthermore, a viper can control every element in the movement of its fangs. It can open its mouth until its gape is effectively 180 degrees wide and not even erect its fangs. It can also bite without discharging any venom. And it can bring each fang forwards separately or together. The fangs themselves are shed every six to ten weeks and replaced with new ones that appear alongside the old.”
― David Attenborough, Life in Cold Blood

“The elapids as a group are dangerous animals. They include the most terrifying of all snakes, the king cobra (Ophiophagus hannah). This species fully deserves its regal status. It is easily the biggest of all venomous snakes, reaching a length of 5.5 metres. It is thought to be among the most intelligent of all reptiles. If threatened it rears up almost to the height of a man, spreads its neck into a hood and growls loudly. It is the only snake to make a nest of leaves for its eggs. This it will actively defend against intruders of all kinds, including elephants which it can kill with a bite on their trunk. And its main food is other snakes-pythons, rat snakes and even other lesser cobras.”
― David Attenborough, Life in Cold Blood

“The body of its victim travels slowly down the snake’s throat. The snake’s lack of front limbs and pectoral girdle means that there is no bony ring encircling its shoulders through which its prey has to pass. The skin of the snake’s tubular body is also elastic and stretches as the muscles of its body wall steadily force the meal down towards the stomach where the process of digestion will at last begin. If the meal has been a big one, this may take some time. If its victim had spines or even horns then sudden movement could cause a puncture of the snake’s body wall. So the snake will now do its best to keep out of harm’s way and avoid too much activity.
Particularly large meals stimulate changes in the snake’s internal organs that are necessary to deal with the task of digestion and storage. Its heart swells by 40%. Within two days, its liver has doubled in size. Absorbing the whole meal may take a week or more. When at last the task is completed, the snake’s bodily systems shut down once again, leaving only the equivalent of a pilot hght activated.”
― David Attenborough, Life in Cold Blood

“A young male shingleback (skink), in spring, travels quite widely through the semi-desert, seeking a partner. He identifies a female by her chemical scent, her pheromones. He may then start to follow her, trailing behind her with his head close to her tail. The pair may stay together for six to eight weeks. If she is not physiologically ready to receive him, she will keep her body close to the ground. But eventually her mood may change and she will straighten her hind legs so that the rear of her body is lifted above the ground. He then crawls beneath her and twists his body so that their cloacas meet and he is able to insert his sperm. The two then separate and go their own ways.
Unlike many lizards, the female retains her fertilised eggs within her until the young are so well developed that they are capable of independent life. This takes a long time. They grow so large that there is only room within her body for a very small number of them — usually no more than three. Then at last, after five months, she gives birth.
The young waddle off into the desert and the female resumes her lonely life. But when spring returns, an adult will once again seek out the partner it had during the previous season. Such partnerships may last for as long as two decades. If one individual is killed, perhaps, as happens only too often, crushed beneath the wheels of a car, the survivor may stay beside the body gently licking it. A coldly dispassionate explanation of this is, of course, that the bereaved has formed a liking for its partner’s pheromone and is reluctant to leave its source. Other interpretations, more sentmental and anthropomorphic, might suggest that the survivor is disconsolate — if not grieving.”
― David Attenborough, Life in Cold Blood

“Reptile eggs are easily damaged. The parchment in which they are wrapped — which allows adults to breed away from open water — is not wholly impervious. In a dry atmosphere, it would allow so much liquid to escape that the contents of the egg would desiccate, and the embryo die. The eggs are also killed if they overheat or are seriously chilled. All lizards, therefore, take great care about where they place their eggs. Many species of monitors bury them at the end of long tunnels. Some, however, including the perentie, have discovered a way of providing their eggs with an environment that remains at exactly the same temperature and humidity whatever the weather-and without any effort whatsoever on the part of the females. They lay their eggs inside a termite nest.”
― David Attenborough, Life in Cold Blood

“Anoles (species of Anolis), American members of the iguanian clan, reinforce their head-bobbing signal in a special way. Like all iguanians, they have a muscular tongue that forms a large fleshy lump in the floor of the mouth. This has an internal scaffolding, part-cartilage part-bone, that is known as the hyoid. Its main component is a substantial rod that helps to support the tongue and enables iguanians to project their tongue forwards and use it to pick up insects. The anoles, however, have a rather more elaborate hyoid. There is a second rod, hinged to the base of the main one, that extends downwards into the skin on the underside of the throat of the males. The anole can flick this down and forwards so pushing out a triangular-shaped flap of skin. In some species this is coloured a brilliant red, in others a pale yellow. It is so big that when it is extended, it projects well beyond its owner’s chin. The vivid flash this creates can be seen from many yards away as a stab of light in the gloom of the forest.
Creep up towards a displaying male, holding a mirror in your hand, and as he catches sight of himself he will respond with repeated flicks of his throat flag. Persist and he may become so infuriated by this rival who does exactly what he does that he may eventually turn around and abruptly leap at the mirror in an all-out attack”
― David Attenborough, Life in Cold Blood

“Caimans sometimes adopt a creche system. Several females will use the same nursery pool. As the young grow, mothers begin to leave until a single female is left guarding as many as a hundred youngsters in a single pool.”
― David Attenborough, Life in Cold Blood

“Female caecilians, however have many different ways of dealing with their young. One Brazilian species feeds them with her own skin. The female lays her eggs in cluster and then protectively curls her long body around them. After they hatch, the young-at three day intervals-suddenly and simultaneously start to bite her flanks and tear off strips of skin. She lies there passively, allowing them to swarm all over her until she has been stripped of the entire outer layer of her body. The frenzy lasts for some seven minutes. Then the family rests for three days while the female grows another layer of skin-and another meal.”
― David Attenborough, Life in Cold Blood

“Many amphibian eggs are black with the pigment melanin that protects their delicate cells from damage by ultra-violet light. Newt eggs, however, are white and lack pigment so they need protection of leaves.”
― David Attenborough, Life in Cold Blood

“The axolotl is remarkable because it becomes sexually mature while still retaining the external gills of its larval form. It seems, however, that this is due to nutritional problems. The change from larva to adult is triggered by hormones, including thyroxine produced by the thyroid gland. Conditions in this one lake, both chemical and physical, are such that this gland does not develop properly. But that can be corrected. If an axolotl (Ambystoma mexicanum) is kept in a tank and a little thyroxine added to its water, the animal loses its external gills, climbs out of water and assumes a terrestrial life.”
― David Attenborough, Life in Cold Blood

“Such an intermediate form between egg and adult that is capable of independent life is known as a larva. All insects except the most simple and primitive pass through such a stage of development during their lives and often exploit it by drawing upon two different food sources during the course of their lives, one as a larva and the other as an adult. Amphibians are the only group of backboned animals to have such a stage in their life history. Interestingly, the newly hatched larvae of salamanders are indistinguishable to the naked eye from the hatchlings of the Queensland lungfish.”
― David Attenborough, Life in Cold Blood

“The chances of any individual animal leaving behind fossilised remains are infinitesimal. First, its dead body has to lie in a place where sediment accumulates. That is most commonly in a lake or sea. Bones lying on the surface of the land are much more likely to be destroyed than preserved. Next, the sediment has to cover the bones before they disappear, preferably even before they are disarticulated. After that, the mud-and the bones within it- has to be compressed and turned into stone by the great, infinitely slow, movements that distort and crumple the earth's crust. That has to happen without the total obliteration of any sign of the bones. And finally, those bones have to be located in the tiny proportion of rocks which happen to be sufficiently close to the surface for them to be discovered by a prospecting palaeontologist. Thus not only have the vast majority of individual animals disappeared without a trace but great numbers of species and families have doubtless existed of which we have no knowledge whatsoever.”
― David Attenborough, Life in Cold Blood