Study Explains Why Black Widow Spiders Are Moving Farther North Than Before

Recently published research suggests that black widow spiders are moving to areas that are located even farther north than before due to the effects of climate change forcing them to look for more ideal temperatures.

In a study that was published earlier this week in the journal PLOS One, a team of researchers noted that there has been an increase in the number of black widow spider sightings in more northern areas over the past five decades. As a result of this phenomenon, the poisonous spider’s range has extended by more than 30 miles, the researchers wrote.

According to BGR, the findings were noteworthy in part because of the methodologies used by the researchers, as they didn’t just gather data from professional scientists, but also from citizen scientists who have used the internet as a tool to make their discoveries public.

“In our project, the citizen science data was essential in modeling distributions of spiders,” read a statement from lead author Christopher Buddle, a professor at McGill University in Montreal.

“People who are excited about discovering where species live can contribute in meaningful ways to scientific progress and this is exciting, important, and is changing how we do research.”

Aside from talking to professional and amateur scientists, the researchers also collected their distribution data from existing scientific literature, museums, personal collections, and research centers. The study also noted that two “poorly documented” black widow species — the Northern black widow and the black purse-web spider — were chosen for their research, as the scientists sought to determine if museum and citizen science data could be blended to come up with accurate distribution models for such species.

Due to the aforementioned northward shift, black widow spiders are now found “well into parts of Canada” and in some parts of Wisconsin, as climate change has driven the creatures to parts of the world which were previously believed to be out of their range. The researchers also stressed that their revised distribution map for the black widow could be the “most accurate” of its kind.

According to a National Geographic fact sheet, black widow spiders are considered potentially deadly creatures due to their venom, which is thought to be about 15 times stronger than that of a rattlesnake. While their bites could cause muscle pain, nausea, and breathing difficulties in humans, they are rarely fatal, except when the victims are young children, elderly individuals, or people who are “infirm.” Black widows are generally found in temperate regions, as further explained by the fact sheet.