Spiders are a common part of ecosystems across the globe, inhabiting diverse environments from dense forests to urban dwellings. These arachnids are primarily predatory, consuming a wide array of insects and other small creatures, playing a role in many food webs. Despite their predatory nature, spiders themselves are a food source for numerous animals, ranging from other invertebrates to various vertebrate species. The animals that prey on spiders often depend on the spider species, its size, and its habitat.
Insects That Hunt Spiders
Many insect species hunt spiders, employing diverse and specialized strategies. Spider wasps (Pompilidae) are known for their unique predation method. A female spider wasp stings and paralyzes a spider, often a wolf spider or tarantula, before dragging it to a nest where she lays a single egg on its body. The wasp larva then hatches and consumes the immobilized spider. Adult spider wasps typically feed on nectar.
Praying mantises readily consume spiders, among other insects. They use their powerful, spiny forelimbs to quickly snatch and hold prey. Robber flies (Asilidae) are predatory insects that hunt spiders, often capturing them in mid-air.
Other insects and arthropods also include spiders in their diet. Assassin bugs and beetle species prey on spiders. Centipedes, multi-legged arthropods, also hunt spiders, paralyzing them before consumption.
Vertebrate Hunters of Spiders
A wide variety of vertebrate animals incorporate spiders into their diets. Many bird species, particularly insectivorous ones, forage for spiders. Common examples include wrens, chickadees, warblers, robins, sparrows, and blackbirds. Spiders are a valuable food source for birds, providing nutrients like taurine, beneficial for their young. Birds may pluck spiders from webs, glean them from foliage, or catch them in aerial swoops.
Small mammals also prey on spiders. Shrews and mice readily consume spiders. Some bat species also include spiders in their diet. Some primate species, such as marmosets and tamarins, may supplement their diets with spiders, especially in tropical regions.
Amphibians like frogs, toads, and salamanders often prey on spiders. They use their long, sticky tongues to capture small invertebrates they can ambush. Reptiles, including lizards and some snakes, also consume spiders. Geckos, chameleons, and anoles are examples of lizards that frequently hunt spiders, often attracted by their movement. Smaller snake species, like garter snakes, occasionally eat spiders.
Spiders as Predators of Other Spiders
Spiders are also preyed upon by other spiders, a phenomenon known as araneophagy. Cannibalism is common among many spider species, especially when resources are scarce or during reproductive interactions. Female spiders, particularly in species like black widows and some wolf spiders, engage in sexual cannibalism, consuming the male before, during, or after mating.
Some spiders specialize in hunting other spiders. Pirate spiders (Mimetidae) are known for their deceptive hunting tactics. They often invade the webs of other spiders and mimic the vibrations of trapped prey or a potential mate, luring the web’s owner closer before attacking. Pirate spiders possess specialized venom effective against other arachnids.
Jumping spiders (Salticidae), with their exceptional vision and agile movements, also prey on other spider species. They actively stalk and pounce on their prey, including smaller spiders they encounter. This predatory behavior among spiders highlights the complex and interconnected nature of arachnid food webs.