Table of Contents
Table of Contents
Introduction
Chapter 1 What Is a Spider? Chapter 2 Nocturnal Hunters Chapter 3 Daylight Visual Hunters Chapter 4 Jumping Spiders Chapter 5 Ambushers and Lurkers Chapter 6 Trappers: Orderly Webs Chapter 7 Trappers: Disorderly Webs Chapter 8 Tunnel-web Builders Chapter 9 The Nonconformists Chapter 10 Photographing Spiders
Postscript Acknowledgments Bibliography Index
Introduction
If you wish to live and thrive Let the spider run alive — traditional English rhyme
Wherever we are, there is likely to be at least one spider within a few feet of us. It may be weaving a web, floating by on a gossamer thread, dancing to its mate, sucking the juices from an anesthetized fly or simply resting under our chair. Whatever it is doing, we are privileged to share the planet with about 40,000 known species of these remarkable animals.
Spiders are the most successful terrestrial predators on earth, occupying almost every niche possible. They are found from mountaintops to seashores and from ponds to deserts. They can even be found thousands of feet up, traveling vast distances as they balloon through the air on threads of gossamer. Spiders have been around for some 400
million years now and were pivotal in the evolution of insects, the most abundant class of animals on earth. Spiders consume more prey than all other carnivores. The late W.S. Bristowe, a British arachnologist, established that at certain times undisturbed meadows can support an astonishing population of more than two million spiders per acre, and that the weight of insects consumed per year by spiders easily exceeds the weight of the entire human population of England.
The success of spiders is almost wholly due to the formidable and astonishing array of techniques they have evolved for trapping insects and other small creatures. Their tactics are the result of a 300-million-year arms race fought against the insects. These range from a variety of ingenious traps in the form of webs to a host of other devious methods, including lassoing, jumping, stealing, chasing, ambushing, spitting, fishing, masquerading as other animals and even attracting prey by mimicking the prey's pheromones. My fascination with this stunning diversity of hunting techniques largely inspired the creation of this book.
It seems unfortunate that many naturalists and organizations concerned with conservation have tended to concentrate on the more obviously attractive groups of invertebrates, such as butterflies and dragonflies, as is clear from the many books on those subjects. The vast majority of spiders are not brightly patterned and colored; being tender and vulnerable creatures and surrounded by a profusion of enemies, they rely on merging with the subtle shades of their surroundings. Their coloring is usually composed of beautifully delicate patterns of browns, greens and grays, as reflected in the photographs in this book.
Another reason for their comparative neglect is that spiders are often tricky to positively identify. More than half are only 0.04 to 0.2 inch (1-5 mm) long, and the differences between many species can be discerned only under a microscope. Here, though, we are concerned mainly with the larger and more significant species. The difficulties of spider identification are hardly made easier by their numbers — more than 640 named species in England alone and about 3,700 in North America. In contrast, there are only about 65 British butterflies and around 700 in North America.
Spiders also have an image problem, so this book attempts to offset their creepy reputation. They possess rather a lot of legs to worry about; they are known to have a poisonous bite; they sneak about in dark places, scuttle across the floor at high speed and leave untidy webs all over the place. Paradoxically, though, many spiders are actually creatures of sunlight and are not at all creepy. The jumping spiders, by far the most numerous single group, have an enchanting and, some would say, almost cuddly appearance as they run jerkily over rocks and tree trunks, their large eyes following our every movement.
The aspect that most concerns many of us is actually the last thing we need to worry about — their bite (apart from some notorious exotic species). Even the few non-exotics that can nip do so only in self-defense, when severely provoked or squashed against our body. In reality most spiders are very nervous and retiring creatures because, unlike insects, which are protected by a tough exoskeleton, spiders have soft and vulnerable bodies. They do everything possible to keep out of harm's way, disappearing into their hiding places at the slightest disturbance or sign of danger. Many come out into the open only at night, spending the day hiding in some crevice or curled up in a leaf.
Spiders, like so many other animals, including humans, are predatory carnivores, but they are more humane than most others, albeit unconsciously so. This might seem like anthropomorphizing, but many of the predators we admire — such as owls,
eagles and tigers — usually tear their relatively intelligent victims limb from limb while they are still alive, while the spider will first anesthetize its prey or, more likely, kill it with a lethal injection! We should also bear in mind that the nervous system of a spider's invertebrate prey is thousands of times less elaborate than that of any vertebrate, so their capacity to suffer is insignificant compared with the prey of larger carnivores.
There are a number of ways of organizing a book of this nature, for example, by family or habitat. Most spider books are based on classification, which is a sensible approach for identification and more serious study of the subject, but a slightly different course has been adopted here. In view of the range of ingenious hunting methods used by spiders, in this book they are grouped as follows: those that hunt down their prey by chasing, those that lie in wait and ambush, spiders that leap onto their victims, and of course the majority, which spin webs to trap insects, the latter being subdivided by different types of webs — orb webs, sections of orbs, sheet webs and funnel traps. Finally there are spiders that don't neatly fit into any of these categories — the nonconformists, those that tend to employ even more freakish techniques such as spitting, fishing and raiding other spiders.
It will soon become clear that these demarcations are not set in stone, as some species within one group often share the characteristics of another. For instance, many spiders that are capable of chasing down their prey may sit and wait for prey to come within reach before making a quick dash, so these could equally be described as ambushers. Similarly, some of the web builders do not actually trap prey in their webs but dash out of a hole or tunnel at high speed as soon they sense an insect touching a strand, while there is a good case for classifying fishing spiders with the chasers instead of bundling them with the nonconformists. Nevertheless, the broad divisions adopted here do help to demonstrate the range of hunting styles employed by these astonishing animals.
Unless it is unusually spectacular, I have avoided explaining much about courtship and mating behavior, particularly as several other books, including W.S. Bristowe's The World of Spiders, cover this topic in lavish detail. What has been included is a rough-and-ready translation of the scientific names. Whereas most of the names appear sensible and logical, others do not seem to have any obvious connection with the spider's appearance or way of life. Nevertheless I find them interesting — and at times amusing.
This book would not be complete without mentioning its omissions. For instance, we hardly touch upon the many minute spiders that require high magnification to see, let alone identify. These spiders mostly belong to a single vast family, the Linyphiidae; two of the larger species are portrayed here. Also excluded are many families specific to the tropics and Australasia and Africa. What is covered are the most important families common to both northern Europe and North America, together with a few representative "special" spiders that thrive in one continent but not the other. For example, the ladybird spider (Eresus) and the water spider (Argyroneta) are both European species that are not found in North America, whi
