Venomous black widow spiders appear to have advanced further into densely populated parts of Canada, and the reason for the worrisome migration apparently lies in a warming climate, according to a new study published in the journal PLOS One.
The survey conducted by scientists from McGill University found that regular sightings of black widow spiders in more northern areas have steadily risen over the last half century, and the habitat of the potentially deadly spider has expanded by over 30 miles in view of the Earth’s surface becoming increasingly warmer. The latter constitutes the necessary conditions for the spider to thrive.
The northernmost range of the spider now stretches into the vast lands of Canada, while sightings have also come in from areas near Wisconsin, which had previously not been inhabited by the species.
The survey features not only professional research but is to a great extent based on citizen scientists’ accounts, which makes the findings particularly valuable.
"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," said Christopher Buddle, a McGill professor and a co-author of the research paper.
The black widow's venom is extremely powerful, causing muscle pain, nausea, and even paralysis of the diaphragm, which may further lead to death.