What kinds of spiders can you find in Alberta?
Many people are terrified of spiders and find them extremely creepy. This is unfortunate because they are incredibly interesting creatures and crucial to our environment! Luckily, most spiders are harmless, and they control the insect population.
Today, you will learn about the most common spiders that live in Alberta.
Before we begin, note that the list below is just a fraction of the overall number of spiders found in Alberta. Because of the sheer number of these arachnids, it would be impossible to cover them all. With that being said, I did my best to develop a list of COMMON spiders that are often seen and easily identified.
13 Spiders in Alberta:
#1. Wolf spiders
Wolf spiders are one of the most recognizable spiders in Alberta!
They are found everywhere and in almost any habitat. I know that I see them often when flipping over rocks or logs. Unfortunately, there are so many individual species of wolf spiders that it would be impossible to list them here, especially since most look very similar.
Interestingly, wolf spiders do not make webs to catch their prey. Instead, they wait for an insect to walk by and then chase it down! Likewise, some species will make a burrow and then wait inside for dinner to walk by.
When it comes to arachnids, wolf spiders have incredible eyesight. They also have retroreflective tissue in their eyes, which produces a glow if you flash light at their faces.
Wolf spiders will bite if provoked, but their venom is not dangerous to humans. Bite symptoms are minimal and may cause itching, swelling, and mild pain.
#2. Cellar Spider
- Cephalothorax (head) and abdomen are different shades of brown.
- Less than a 12.7 mm body and 51 mm long legs, and the body is the shape of a peanut.
- Some species have 8 eyes, while others only have 6 eyes.
You know that spider that is always in the corners of your basement?
Well, it’s most likely a Cellar Spider! These long, thin, and delicate arachnids are commonly found in Alberta in homes and buildings. Whenever I clean my basement with a vacuum, a few of these spiders always seem to get sucked inside.
Cellar Spiders do something exciting when their web is disturbed by touch or has entangled large prey. They start vibrating rapidly, which has led to them sometimes being called “vibrating spiders.” They do this behavior to hide from predators or increase the chance of catching an insect that brushed up against their web.
Cellar Spiders are beneficial to have around because they have been known to hunt down and kill venomous spiders.
#3. Crab spiders
- On average, females measure 7–11 mm. Males are much smaller and range between lengths of 2–4 mm.
- Colors range widely based on the specific species. However, the most common colors are pink, yellow, white, green, or brown.
The best places to find crab spiders in Alberta are near flowers.
Crab spiders don’t use webs to catch their prey. Instead, they sit and wait inside flowers or other vegetation low to the ground for something to eat. Once a suitable victim comes by, they use their long forelegs to ambush it and make the kill. When insects are in short supply, such as during bad weather, they eat pollen and nectar to avoid starvation.
Lastly, many crab spiders have developed a mutualistic relationship with certain plant species since these spiders feed on and help deter harmful insects. Some plants even release an emission after being attacked that helps attract crab spiders in hopes they eat the intruder.
#4. American grass spiders
- Both sexes are shades of brownish-black with stripes running from front to back.
- The abdomen is oblong and has two white stripes broken into sections.
- The head has a lighter stripe running down the middle, dividing the two dark stripes.
Grass spiders are one of the fastest spiders in Alberta.
Grass spiders are funnel weavers, which means they weave a funnel on one edge of their web. Their webs are not sticky, like other spiders. But once the silk is triggered, they use their speed to run quickly to get their prey.
Fortunately, they are harmless to humans. And they typically stay in their webs unless disturbed.
*The genus Agelenopsis consists of 14 species of grass spiders that live in North America.
#5. Black Widow
- Females are 6.35 mm to 9.5 mm long.
- Shiny black with a distinctive red hourglass-shaped mark. A row of red spots is sometimes visible above.
- Males are half the size of females but have longer legs.
Black Widows are the most venomous spiders in Alberta!
In addition, they are probably the most popular and recognizable spiders in the world. Almost everyone knows the red-shaped hourglass mark that appears on females.
And even though they have highly toxic venom that is 15 times stronger than a rattlesnake, they are not aggressive. The Black Widow only bites defensively if the web is disturbed, and they RARELY bite humans.
But, if you are one of the few unlucky people who are bitten each year, you should know that the venom affects your nervous system. Some people are only slightly affected by it, but many have a severe response. If you are bitten, the bite requires medical attention, and the neurotoxic venom can be fatal to small children if untreated.
#6. Fishing spiders
They’re also known as Fishing Spiders, Raft Spiders, Dock Spiders, or Wharf Spiders.
- Both sexes can vary in color; some are brown, black, or cream-colored brown.
- Many species have a striking pale stripe down each side of the body; others have dots down the side of their body.
Fishing spiders are some of the largest spiders in Alberta.
Several different species are found here, and they are all large nocturnal spiders that find their prey around water. You’ll often see them on the docks by a lake during the day.
These arachnids have special short velvet-like hairs that don’t get wet, allowing them to stand or run on the water. They wait for prey to make a ripple, then race across the water to grab it. Most fishing spiders eat insects, but some species can catch small fish.
They can also hunt underwater because of their specialized lungs, which help them breathe while submerged. However, the air in their lungs makes them float, so they need to hold onto a rock or plant, or they will rise to the surface.
#7. Common House Spider
- Parasteatoda tepidariorum
- Both sexes can appear anywhere from nearly black to a variety of colors.
- They sometimes have patterns of different colors on their body.
- Females are larger than males. Females also have a bulb-like abdomen that males lack.
These spiders are found in Alberta NEAR PEOPLE!
I know that I always find them in my garage! It always surprises me how small Common House Spiders are, as they are generally only between 5 and 6 millimeters long.
Even though there are probably a few in your house right now, you shouldn’t hate Common House Spiders. They are actually helpful because they feed on small insects and pests in your house, like flies, ants, and mosquitos.
They are relatively docile spiders, but bites do occur mostly due to their proximity to humans. But have no fear; their venom is not dangerous in the least.
#8. Harvestmen (Daddy Longlegs)
- Colors vary; most are dull brown or dull gray, but some may be yellowish, greenish-brown, or reddish.
- Look for a dark blackish streak down the middle and sides.
- Single body region, only two eyes that do not see well.
“Daddy Longlegs” might be the most recognizable spider in Alberta!
We often see them in our yard, typically hiding underneath my kid’s playground or on rocks or logs. They are also very social, so you will often find them in large groups.
But even though Harvestmen look just like spiders, these arachnids are technically NOT spiders!
They are in the Order Opiliones, have no venom, lack fangs, and do not bite. In addition, Harvestman can swallow solid food, which allows them to eat small insects, fungi, dead organisms, bird dung, and other fecal matter. This differs from spiders that only eat their prey after turning them into a liquid.
As you might guess by their nickname, their legs play a vital part in their life. They use their legs for breathing, walking, smelling, and capturing prey. Males have longer legs than females, which they groom by licking. Seriously, you can watch this behavior in the video above!
#9. Banded Garden Spider
- Argiope trifasciata
Also known as the Banded Orb Weaving Spider.
- This species has an oval abdomen and bright body markings. The back of the abdomen is pale yellow with silvery hairs and lateral bands of black stripes. Males are usually paler, sometimes even white.
- Adult females are around 13 to 14.5 mm long.
- Males are considerably smaller, reaching only a third of the females’ length.
The Banded Garden Spider builds an enormous web, typically around 23.6 in (60 cm) in diameter. The web itself is sticky and strong, able to hold very large insects like wasps and grasshoppers. One interesting feature of their webs is the so-called “stabilimentum,” a vertical zigzag pattern made from dense silk. Researchers think this feature is a way to attract insects that the Banded Garden spider eats.
Females usually rest at the center of the web, facing downwards. They face their webs east-to-west to take advantage of the rising and setting sun and hang in the center with their dark underside facing south. All this allows them to gain as much warmth as possible, enabling them to stay active later in the year.
These spiders rarely bite humans in Alberta and are not aggressive.
They may bite in self-defense if handled and bothered, but it’s unlikely that the bite would cause more discomfort than a bee sting.
#10. Marbled Orbweaver
- Araneus marmoreus
- A large orange abdomen with brown or black marbling, although they range in color (from yellow, white, black, brown, or red).
- Females grow up to 18 mm, with males being half that size.
- The legs are red with black and white banding beginning on the tibia.
Due to the large, orange abdomen, Marbled Orbweavers are often called “Pumpkin Spiders” and are fairly easy to identify. Look for these spiders in Alberta from mid-summer until the weather turns cold. The best places to find them are in moist, wooded areas along the banks of streams.
Their webs are oriented vertically, and Marbled Orbweavers attach a signal thread to the middle, which alerts them when prey has been captured. Unlike many garden spiders that sit at the center of their web, this species hides in a silken retreat constructed to the web’s side. They often hide under leaves or other debris they have stuck together with webbing, waiting patiently for a meal to get stuck.
#11. Zebra Jumping Spider
- Salticus scenicus
- Their anterior median eyes are large, which gives them excellent binocular vision.
- The coloration looks like a zebra; black with white stripes.
- Female spiders are 5–9 mm long, while males are 5–6 mm.
Zebra Jumping Spiders are found in Alberta in open, vertical habitats.
Rock faces and tree trunks provide good habitat, but they are also found in close proximity to humans on the walls of buildings and garden fences. You should also check the corners of the windowsills in your house, as they are sometimes found there too. 🙂
Jumping spiders don’t use webs to capture prey but instead use their incredible eyesight for hunting smaller spiders and other invertebrates. Once their victim is sighted, they move slowly toward it until they are close enough to jump on and make the kill, similar to how a cat hunts. Then, just in case they miss the target, they attach a silk thread to a surface so they can climb back up and try again!
To try and impress a potential mate, male Zebra Jumping Spiders will conduct a courtship dance by waving their front legs and pedipalps while also moving their abdomen up and down. A better dance increases the likelihood that the females will want to mate with the male. Males must be VERY careful when approaching the female; if the dance isn’t good enough, they risk being eaten.
#12. Cat-faced Orbweaver
- Araneus gemmoides
Also known as the Jewel Spider and Cat-faced Spider.
- They are found in many different colors.
- Identified by the two horn-shaped growths found on the large abdomen.
The Cat-faced Orbweaver is a common spider in Alberta.
Look for their webs near lights, closed spaces, and on the sides of buildings.
After laying a single egg sac filled with hundreds of babies, the female dies a few days later. As the spiderlings hatch from the egg sac, many of them will eat their siblings as their first meal!
The baby spiders that survive predation from their brothers and sisters have an interesting way of traveling to new locations. The spiderlings can float many miles away by riding strands of silk that are blown in the wind!
#13. Johnson’s Jumping Spider
- Phidippus johnsoni
Also known as the Red-backed Jumping Spider.
- Adults are about 10 mm long.
- Both males and females have a red abdomen. The rest of the body is mostly black.
- The chelicerae (mouthparts) are a bright teal color.
This species is one of the largest and most common jumping spiders in Alberta! Johnson’s Jumping Spiders typically construct silken nests on the ground that are found underneath rocks and wood.
They prey on almost any insect that is smaller than them. But interestingly, other spiders make up a large part of their diet. Cannibalism is also common in females as they dine on smaller males.
And the most interesting fact about Johnson’s Jumping Spiders is that one was sent to space in 2012! Nicknamed “Spidernaut,” the spider traveled to space for 100 days to see if jumping spiders could adapt to the microgravity in space and then transition back to Earth. Read all about the experiment here. 🙂
Learn more about animals found in Alberta!
6 Common SNAKES That Live in Alberta! (ID Guide)
33 Common Bird Species Found in Alberta! (With Photos)
Do you need more help identifying a spider you found in Alberta?
Try this field guide!
Which of these spiders have you seen in Alberta?
Leave a comment below!