Catherine Scott is a graduate student working toward her Ph.D. at the University of Toronto. She’s studying the courtship behaviour of black widow spiders. That means that her experiments often involve waiting for spiders to have sex.
And because her lab keeps a breeding colony of spiders (so they don’t have to go out into the field and capture new adults for every experiment), even when she’s not doing experiments she can be waiting for spiders to have sex. That was the case last Friday, when she set up four mating arenas to try to bulk up the numbers of one black widow species in the lab.
Once she’d put a male and a female in each case, she settled in to watch. When we asked why, she explained, “I was sitting in the room hoping to catch them in the act because it’s easier to tell for sure that they are copulating in real life than by reviewing the video footage.”
Her wait, recorded in tweets, give you a taste of how much patience goes into studying animal behaviours.
So… what are y’all up to?
I’m waiting for some spiders to get it on, & they are taking their sweet time #science
— Catherine Scott (@Cataranea) October 23, 2015
By 2:00 pm on Friday afternoon, she’s already spent two hours watching male and female spiders act like teenagers at a Year 8 dance.
oh wait no, the first male to make contact has taken a step back, and is now engaged in some serious self-grooming.
— Catherine Scott (@Cataranea) October 23, 2015
Things start looking up when one male shifts into courtship behaviour.
MALE #1 IS THROWING SILK ON THE FEMALE! this is where it starts to get exciting, folks. The ‘bridal veil’ is happening!!!!
— Catherine Scott (@Cataranea) October 23, 2015
But he backs off.
Nevermind, I spoke too soon. He’s gone back to destroying the female’s web.
— Catherine Scott (@Cataranea) October 23, 2015
Hopes are raised, and dashed again moments later.
oh wait he’s back! more sexy silk wrapping is happening…. but the female starts moving and he beats a hasty retreat
— Catherine Scott (@Cataranea) October 23, 2015
And over in the other arenas, there’s not a lot of courting going on.
Female 3 has stopped moving finally. Come on male 3! Now is your time to shine!
— Catherine Scott (@Cataranea) October 23, 2015
….. male 3 remains motionless ….
— Catherine Scott (@Cataranea) October 23, 2015
now female 2 is on the move, & male 2 has retreated to the far edge of the web. This is going to be a long day.
— Catherine Scott (@Cataranea) October 23, 2015
Leaving Scott to put her hopes on the pair in arena #1.
I have high hopes for male #1. He’s going to mount the female any time now, I can feel it.
— Catherine Scott (@Cataranea) October 23, 2015
As I said, the sexy red mood lighting is on. I don’t know what more I can do. @AkulaEcho
— Catherine Scott (@Cataranea) October 23, 2015
This is the point when we find out she’s not just waiting for the spiders to have sex, she’s sitting in the dark waiting for the spiders to have sex. Ah, science.
Black widows are nocturnal, so we do experiments during the night, under red light, which they can’t see.
— Catherine Scott (@Cataranea) October 23, 2015
Back in arena 1, there’s some potential action.
… and the female casually brushes him aside with a hind leg. He drops on a dragline, and regroups.
— Catherine Scott (@Cataranea) October 23, 2015
Apparently, males can do this for hours.
Male #1 is boldly approaching the female for a second try. He is vibrating his tiny little abdomen like a champion.
— Catherine Scott (@Cataranea) October 23, 2015
Male 1 is carefully laying down a light silk wrapping on the female’s front legs
— Catherine Scott (@Cataranea) October 23, 2015
Now he’s right on top of her, but a layer of webbing lies between him and the female. That’s not gonna work, male #1.
— Catherine Scott (@Cataranea) October 23, 2015
MALE #1 HAS DONE IT. HE HAS MOUNTED THE FEMALE!
— Catherine Scott (@Cataranea) October 23, 2015
Huzzah! But after a couple of minutes…
Male #1 has evidently decided that the timing wasn’t quite right. He has dismounted, and moved to the opposite end of the web. ::::(
— Catherine Scott (@Cataranea) October 23, 2015
Female 1 is presumably tired of all these shenanigans. She’s brushing off the silk the male lovingly wrapped around her.
— Catherine Scott (@Cataranea) October 23, 2015
Male #1 tries to approach the female two more times, but she doesn’t seem that interested.
He’s wrapping more silk around the female! Maybe this time it’ll stick
— Catherine Scott (@Cataranea) October 23, 2015
She (very slowly) chases male # 1 to the opposite end of the web
— Catherine Scott (@Cataranea) October 23, 2015
She appears to be starting in on repairs, oblivious to the fact the male #1 is still courting below
— Catherine Scott (@Cataranea) October 23, 2015
What about the other arenas? Nope, no spider sex there, either.
For those just tuning in, we’re following the behaviour of 3 pairs of black widows that are *supposed* to be mating
— Catherine Scott (@Cataranea) October 23, 2015
In arena 1, we have male #1, equipped with only one palp, but of the 3 males, the only one that has managed to mount the female
— Catherine Scott (@Cataranea) October 23, 2015
In arena 2, we have male 2 and female 2. Female 2 has been motionless for some time. Male 2 has been grooming for a good 15 minutes.
— Catherine Scott (@Cataranea) October 23, 2015
And in arena 3, male and female 3 have done nothing at all for, oh, I’m guessing about an hour?
— Catherine Scott (@Cataranea) October 23, 2015
Now that female #1 has made some repairs, male 1 has to go back and do more web reduction
— Catherine Scott (@Cataranea) October 23, 2015
Before male black widows start courting, they destroy part of the female’s web. Scott has found that the behaviour keeps other males from finding the female and edging the first male out. If she fixes her web, the male needs to back up and re-destroy part of it. Scott also explains why it matters that male #1 only has one pedipalp.
In case you were wondering, here’s what a male black widow looks like just after his final moult pic.twitter.com/FGnoPdq5NZ
— Catherine Scott (@Cataranea) October 23, 2015
The cool thing about spiders is that their sperm transfer organs (pedipalps) are totally separate from their gonads, where sperm is produced
— Catherine Scott (@Cataranea) October 23, 2015
When the male matures, he spins a special web and ejaculates sperm onto it.
— Catherine Scott (@Cataranea) October 23, 2015
Then he sucks the sperm up into his pedipalps (the 5th pair of appendages at the front of his body, which are kind of like hands)
— Catherine Scott (@Cataranea) October 23, 2015
With his pedipalps thus “charged” with sperm, he’s ready to go find a female and stuff the sperm inside her paired sperm storage organs
— Catherine Scott (@Cataranea) October 23, 2015
Meanwhile, back in arena 1, male 1 is courting closer and closer to the female.
— Catherine Scott (@Cataranea) October 23, 2015
This is, for those of you counting, male #1’s sixth move toward the female.
Everything is happening all at once! 1 is making contact with the female. The tip of one tarsus is on her abdomen!
— Catherine Scott (@Cataranea) October 23, 2015
Male 1 edges ever closer to the female, but no, not yet. Have patience. @RRoyaute
— Catherine Scott (@Cataranea) October 23, 2015
And he’s sure taking his time about it.
Male #1 is taking a break. He’s hanging right next to the female.
— Catherine Scott (@Cataranea) October 23, 2015
After another 30 minutes, he’s still hanging right next to the female.
We’re back, and as predicted, not much has changed. Male #1 remains motionless. Male #2 is still. Male #3 is – you guessed it – not moving
— Catherine Scott (@Cataranea) October 23, 2015
Scott’s been incredibly patient, but she’s hungry. Fortunately, she has a technological fix for the waiting and watching problem.
Unfortunately, as riveting as these last 5.5 hours have been, I have to go home and eat dinner.
— Catherine Scott (@Cataranea) October 23, 2015
I’ve set the cameras to continue recording in my absence. I’ll check back tomorrow morning and look at the video.
— Catherine Scott (@Cataranea) October 23, 2015
This morning she reviewed the footage.
BTW I was able to go through the video from those mating trials this morning and as far as I can tell not a single mating occurred. ::::(
— Catherine Scott (@Cataranea) October 26, 2015
Photo of male black widow by @Ibycter.