Wolf spiders were so named because their method of hunting was thought, by someone with a great imagination, to resemble that of wolves.
Theresa in her full glory, out hunting near her burrow.
The burrows have a circular entrance with the exact diameter of a large wolf spider abdomen, just over a centimetre. They have no door, but tend to be decorated with leaves and twigs held in place with silk. The burrows descend for 10 to 15 cm and will then travel for about the same length horizontally. The female will put a thin film of web across the entrance to the burrow after she has mated.
The females are up to 27 mm body length while the males are a few millimetres shorter, but with stronger markings. They are a timid spider. When I would sneak up close to photograph them, they always descended backwards into the burrow unless I approached very slowly and gently.
Wolf spiders are night hunters with reasonably good eyesight. The front two of their eight eyes are
proportionately very large. Free-range hunters like the wolf spiders and jumping spiders use their
eyesight, hence the need for larger eyes.
The eye pattern for wolf spiders identifies them as family Lycosidae (the lycosids).
Lycosids have their eight eyes in three rows. The lowest, first row has four small eyes, in a line. The second row has two large forward-facing eyes which have reasonably good sight for a spider. The third row consists of a pair of slightly smaller eyes quite far back on the side of the cephalothorax. two large front eyes
Jumping spiders also have the two prominent front eyes - equal to the best eyesight of any arthropod - but their eight eyes form a curved line around their heads. Shown on the cover of my book, this North American Phidippus mystaceus has four prominent eyes with two more small eyes on either side of the head, continuing the line.
In contrast, web-building spiders can usually only see light and dark and shadows, detecting the world through the web and air movements with their extremely sensitive hairs. They have six or eight small eyes, depending on the family.
Theresa had a male visitor. They have stronger markings than the females.
Once you have found a burrow, the best way to see the spider is to approach gently at night with a bright torch. The wolf spider eyes will reflect the light. You can attract them to the surface during the day with the grass stalk inserted into the burrow entrance. Wolf spiders love the sun. On a sunny day, if you approach the burrow very carefully from a few metres away, you can often see the spiders sunbaking at the entrance. The female will also sunbake her egg sac. Under the film of web across the entrance of the burrow, she will hold the spherical white or pale blue sac in her hind legs and slowly turn it in the sun.
Theresa covered her burrow a bit and then held her egg sac up to the sun, turning it with her hind legs. You can see the legs in this image. She is head down in the burrow.
If the female heads off hunting, she will carry the egg sac attached to her spinnerets at the end of her abdomen. Once the spiderlings have hatched, they will spend a week or two clinging to their mother’s back. Although the first brood may be smaller, a mature wolf spider will carry enough babies to almost completely cover her. If any move onto her eyes she’ll use the small appendages at the front, her pedipalps, to roughly brush them aside much as a windscreen wiper does on a car.
Theresa with young on her back
One of the most exciting afternoons of my life was watching a group of spiderlings that I had been observing since I first sighted the egg sac being spun by Theresa. It was a hot day with a very light breeze. Most of the tiny creatures left Theresa’s back and crawled up a small plant. They lifted their minute abdomens to the breeze and released a filament of silk. They let go of the plant and floated off into the distance. One landed about ten metres away. I marked her landing spot. I was able to follow her for the next two years. Like Theresa, she produced multiple broods of young.
Theresa's spiderlings ballooning. They are just tiny specks of spiders.
The vast majority of the hundred or so spiderlings who ballooned that day would not have survived the next 24 hours. Those who did land safely and manage to avoid predators would have had a very small chance of reaching maturity without being eaten by one of those horrible creatures known as birds. Any burrow of a mature wolf spider is the home of a great survivor.
Theresa of my spiderlings didn’t last many more weeks. Her tragic ending was orchestrated by a White-winged Chough. This was the last thing she saw.