20 June 2012 Wolf Spiders - Male or Female?

The weather couldn't have been any better for a full day of sampling in the field! Today's agenda included picking up our spider prey pitfall cups, taking soil samples from our mesocosms, collecting spiders for our high density plots, and processing our soil samples.

Today marked an important milestone in our time at Toolik. Today was the first day we wore our bug shirts. The weather to this point has been delightful, and the mosquitoes have been very tolerable. I've heard the horror stories about tundra mosquitoes and I'm sure we haven't seen anything yet, but after getting several bites Kiki broke down and was the first to put on her bug shirt. I wasn't far behind, but Amanda showed her tundra experience and held out until late in the day.

In addition to all of our sampling, we gathered roughly 50 spiders by hand. We ran around the tundra with two cups in hand searching the ground for movement. In addition to being small, the wolf spiders are surprisingly quick. The spiders we gathered will be added to our high-density plots. Spider hunting is a lot more fun than it sounds once you get the hang of it!

In addition to determining what kind of spider we have, we also note the gender of each individual. Determining the gender of mature wolf spiders is relatively easy to do by looking for the presence of enlarged pedipalps or "boxing gloves" on males. Spiders have an additional set of appendages, attached just behind the mouth parts, called pedipalps. Sexually mature males have noticeably enlarged pedipalps when compared to female or juvenile spiders.

Lately we have seen a lot of female wolf spiders with egg sacs. Wolf spiders are unique in terms of providing parental care. Female wolf spiders attach their egg sacs to the end of their abdomen and carry it with them until the spiderlings hatch. Spiderlings hatch from the egg sacs, climb onto their mother's abdomen, and hitch a ride there for about a week before venturing out on their own.

Wandering the tundra in boots can be hard on the feet, so we decided to stop for a break at the stream on our way back to camp. We felt fortunate for another beautiful day to work in the field!