Cannibal Spiders

I doubt spiders come to mind when pondering impacts of global warming at northern latitudes. Climate change has had a profound effect on Arctic Wolf Spiders, nobody cares because spiders are easily dismissed. Fun fact – in terms of biomass, wolf spiders in the Arctic outweigh that of regional wolf populations by 80 – 1. That’s a lot of spiders – thanks to longer, warmer summers they’re getting bigger and producing more offspring.

Nature has a uncanny ability to adapt when challenged with brief periods of climatic change. In 2009 researchers predicted warmer Arctic seasons would boost wolf spider size and numbers. Springtails, their prey of choice are wingless fungi eating hexapods. “Science’s Michael Price explains that springtails subsist on a diet of fungi, which consume decomposing plants and release greenhouse gases into the atmosphere. But when wolf spiders keep the springtail population in check, the insects consume less fungus, which triggers faster decomposition of the tundra’s dead plant matter—and more greenhouse gases.” – https://www.smithsonianmag.com/smart-news/how-wolf-spiders-evolving-diet-keeping-arctic-cool-180969735/

Science expected dense populations of wolf spiders to initially cannibalize their own, consume anything smaller than themselves while sorting out territory. They thought more wolf spiders meant fewer fungus nibbling springtails, but that hasn’t happened. Seems climate enhanced hoards of wolf spiders developed a taste for their own, ignoring springtails, favouring opportunistic ambushes of smaller spiders.

Science can’t explain why cannibal wolf spiders no longer fancy springtails. It can state as fact – higher springtail populations mean less fungus, slower decomposition of organic material, thus significantly less greenhouse gas released by the process of decomposition. Are cannibal wolf spiders Mother Nature’s way of mitigating the mess we’ve made?

https://phys.org/news/2020-05-wolf-spiders-cannibalism-arctic.html