In the Arctic – already a strange place to encounter a spider – the likelihood of finding arachnids increases.
According to a new study, arctic wolf spiders can have more offspring than usual thanks to warming temperatures. This means a baby spider boom.
Researchers discovered that arctic wolf spiders, Pardosa glacialisbenefit from the early spring of the climate crisis. They are able to produce more offspring, so-called clutches, because warmer temperatures extend the season when the spiders are active, scientists report.
The researchers dissected individual egg sacks from the spiders and counted the number of eggs and partially developed juvenile spiders. They compared this egg content to the size of the mothers and found that the spiders produced two separate clutches ̵
The spiders born during the second clutch appeared significantly later in the season. In years when the snow melt occurred earlier, the first clutches appeared earlier and the second clutches were larger.
“Women are likely to make their first clutch earlier in these years, so they have time to make another clutch,” the authors of the study, published in the journal on June 24, write Royal Society B. Procedure.
The study provides the first evidence that Arctic invertebrates are producing additional clutches as a result of global warming. “This could be a widespread but overlooked phenomenon due to the challenges associated with long-term collection of Arctic life history data,” the study team explains.
“Given that wolf spiders are a widespread, important tundra predator, we can also expect their increased reproductive rates to affect the population and the food web.”
Some research has shown that these above-average reproductive phenomena can have a different result for the behavior of wolf spiders in the Arctic: cannibalism.
A study published in May in the Journal of Animal Ecology found high levels of competition between spider mothers and their offspring. Wolf spiders have used cannibalism in previous experiments, and the influx of offspring could have the same effect under nature’s new normal circumstances.
Researchers say this effect could also affect the arctic ecosystem as a whole, since wolf spiders are common.
New spidey senses – This baby spider boom is not the first time that spiders are getting weird with climate change.
A 2019 study found that a social spider, Anelosimus studiosushas become more aggressive as a result of increasing tropical cyclones – another effect of climate change. As a rule, the spiders living in groups hunt together, hang around in the same webs and help each other in bringing up children. But hurricanes change the typical social behavior in the colonies, the study found.
“There is a turning point in behavior when very, very aggressive colonies stop working together, kill each other, and the group deliberately dissolves,” said lead study author Jonathan Pruitt Inverse back then. “Combine hurricane increases with global warming and I think you could get something like that.”
Abstract: Spiders in southern latitudes usually produce multiple clutches, but this has not been observed in high latitudes, where activity times are much shorter. However, the timing of the snow melt in the Arctic is advancing, which may allow some species to produce an additional clutch. To determine if this is already happening, we used specimens of the wolf spider Pardosa glacialis caught by pitfalls from the long-term surveillance program (1996-2014) in Zackenberg, NE Greenland. We dissected individual egg sacks and counted the number of eggs and partially developed young animals and measured the armor width of the mothers. When discovering a bimodal frequency distribution of the coupling sizes, as is typical for wolf spiders in lower latitudes that produce a second coupling, we have assigned egg bags to a first or second coupling depending on the coupling size. We tested whether the mean acquisition date differed between the first and the second clutch, whether the clutch size correlated with the female size and whether the proportion of the second clutch produced in one season was related to the climate. We found that assigned second clutches occurred significantly later in the season than first clutches. In years with earlier snow melting, the first clutches appeared earlier and the proportion of second clutches produced was greater. Women are likely to make their first clutch earlier in these years, so they have time to make another clutch. The coupling size for the first couplings correlated with the female size, while this was not the case for the second couplings. Our results provide the first evidence that invertebrates in the Arctic produce extra clutches in response to the warming. This could be a common but overlooked phenomenon as long-term collection of life history data in the Arctic is challenging. Given that wolf spiders are a widespread and important tundra predator, we can also expect their increased reproductive rates to affect the population and the food web.