The Arctic has been seeing warmer temperatures in recent years. That is bad news for humans but it seems as if it is great news for spiders.
Data from Zackenberg, Greenland was studied by scientists in Denmark. Zackenberg is a remote outpost that is further north than all of mainland Canada. Wolf spiders in the area were trapped and tracked between 1996 and 2014.
It’s not unusual for multiple clutches of spiders to be produced every year in a mild climate. It was always thought to be different in the Arctic, where shorter summers were thought to be too short for it to happen.
According to researchers, the spiders in Zackenberg generally produce one clutch of eggs every year and some years, they would produce two clutches. There was a connection between the number of clutches produced and the time of year when the snow disappeared.
“In years with earlier snowmelt, first clutches occurred earlier and the proportion of second clutches produced was larger,” researchers wrote Wednesday in the Proceedings of the Royal Society B.
“Likely, females produce their first clutch earlier in those years which allow them time to produce another clutch,” they continued.
Since the Arctic appears to be warming faster than most of the planet, there may be more of those years with two clutches in the future. During the study of the previous 19 years, researchers noticed that the snowmelt was moving earlier in the year consistently. Spiders were moving from never having the second clutch in the 90s to doing so more than 50% of the time in the final few years of the study.
According to researchers, this could lead to a larger Wolf spider population. It is even more possible because they are at the top of the invertebrate food chain, and in the Arctic, they don’t have natural predators.
The second clutches were typically smaller than the first with fewer than 50 eggs. In the original clutches, the numbers were closer to 100 eggs. On average, the second clutches were appearing approximately 20 days after the first.
Considering that the gap is typically around 30 days in warmer climates, it was a surprising discovery. Researchers are speculating that it could be due to the extended amount of daylight during the summer in the high Arctic.
It is also thought that the warmer weather during the summer may soon have the spiders in Zackenberg having two clutches every year. The researchers feel that the Wolf spiders are already producing more of those second clutches than spiders in the lower Arctic and boreal regions, where they have longer summers.
Health Canada reports that wolf spiders can be found in all of Canada in grasslands, beaches, forests, and gardens. They are a unique type of spider that hunts insects for food rather than building a web to trap them.
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