Spiders, Pacific Northwest
Nearly half the total number of Spiders known to Canada are found in, and quite often, only, in BC. Given their importance to all ecosystems in which they live, one must wonder why these beautiful creatures have received so little attention in the province.
They are ferocious creatures living in the world of arthropods. Theirs is a matriarchal society ruled by females, where males can sometimes be little more than just a meal. The study of these fascinating animals on the BC coast, has, for the most part, been conducted by a few amateur, but dedicated collectors.
Walk anywhere in British Columbia, and you’ll be less than a meter away from a spider. With more than 700 known species in the province, arachnids are everywhere, from mountain tops to inter tidal zones. These creatures are always exciting to watch – from jumping spiders that dance to impress potential mates, to yellow crab spiders that disguise themselves as flowers.
They have an ominous, but often undeserved reputation. Though most spiders are venomous and considered predators, of the many species found in Canada, few are actually considered a health threat. In fact, spiders are actually helpful in controlling other pests in the home or garden, since they feed on other harmful insects.
They rarely bite humans. Although they’re often unpopular, the venom of most species is not very toxic to humans, usually resulting in no more than a slight swelling, inflammation, or itching sensation. Most spiders’ fangs are too small or weak to puncture human skin. Spiders will not usually attempt to bite, unless accidentally trapped against the skin or grasped, or are actively guarding their egg sacs or young.
One of the most common misconceptions about spiders is that they are insects. Spiders are arachnids, and are actually more closely related to mites, ticks and scorpions. Spiders have 2 body parts, 8 legs, and usually 6 – 8 eyes, while insects are classified as having 3 body parts, 6 legs, and generally 2 compound eyes or up to 3 single eyes.
The average life span of a spider is usually 1 – 2 years, but some can live up to 20 years. Spiders lay eggs within a silken egg sac that is often ball-shaped, and either hidden in a web, affixed to a surface, or carried by the female. Spiders may produce several egg sacs, each containing up to several hundred eggs. A spider grows by shedding its skin about 4 – 12 times before maturity. In many species, the mature male often wanders about in search of a mate, while the female has a territory.
All produce silk, which is secreted as a liquid through spinnerets, and hardens on contact with air. Spiders use silk for a variety of purposes, such as: making egg sacs, capturing prey, holding prey, making shelters or retreats, and transferring sperm during mating. Also, spiderlings extrude silk threads, that enable them to be transported by the wind, a process called ballooning.
They are predators that typically feed on living victims. They produce venom that is poisonous to their normal prey of insects, mites, and other small arthropods. Venom is injected through the hollow fangs to immobilize the prey, and begin the digestion process. Spiders can only ingest liquids, so they either inject or regurgitate digestive fluids into the prey. They then suck in the digested liquid food.
Spiders use a variety of tactics to capture prey. Some species are web builders that use webbing to ensnare their victims. Others are hunters that actively search out their prey. Passive hunters, on the other hand, lay in wait for their victims, rather than searching. All are incredible to watch!