Spiders Bred in the City Are Larger and More Fertile Than Those Raised on the Countryside, New Study Suggests
ByA new study has found that female spiders in urban Australia grow larger and better reproduce than their peers that live on the countryside.
According to BBC News, Elizabeth Lowe, a professor at the University of Sydney, was the lead author of the research published in the journal PLOS One. Her team of researchers wanted to learn how expanded urbanization would affect various forms of wildlife.
For their study, Lowe and her team examined the golden orb-weaving Nephila plumipes spider since it is known to live in both urban and non-urban settings. Despite a much more different landscape and not as much vegetation, the urban-bred female spiders grew bigger and had larger ovaries.
"Hard surfaces and lack of vegetation lead to the well-known 'urban heat island' effect, with more heat retained than in areas with continuous vegetation," Lowe told BBC News. "Higher temperature is associated with increased growth and size in invertebrates.
"Urban lighting may also be a contributing factor, as it attracts insects and means more food for spiders in those environments. This increase in prey would result in bigger, heavier, more fecund spiders."
While they were able to determine that city spiders were larger, heavier and more fertile, the researchers could not pinpoint the leading factor, which they will focus on next. The team was able to affirm that urbanization is affecting wildlife, but "the effects of urbanization on wildlife are very varied," Lowe told Live Science.
One finding became apparent though, that spiders like the city and are obviously benefitting from the heat and prey.
"The fact that some spiders benefit from urbanization is a good thing," Lowe told BBC News. "In order to maintain biodiversity in cities, we need to be able to support diverse populations of spiders and other invertebrates.
"By gaining a better understanding of the impacts of urbanization on wildlife in cities, we can work towards creating healthy, functioning ecosystems in urban areas."