Down Under, Spider Species Continue to Grow—Even In the Cities

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As if news from the outback weren't terrifying enough, with a species of spiders larger than 8 inches long, it turns out that the cities may have even larger spiders on their hands.

In a recent study published this morning in the journal PLOS ONE, researchers in Sydney Australia found that one species of arachnids, Nephila plumipes more commonly known as the golden orb-weaving spider, seem to be doing much better as urban dwellers. The inner city species, which is found in shrubland all across Australia's east coast, was found to have higher fat content, larger sizes and even increased egg capacities, as females of the species had enlarged ovaries which the researchers weighed as part of their studies.

But in spite of terrifying arachnophobes, the researchers indicated that this discovery brings lots of good news for the city.

"The larger size and increased reproductive capacity of N. plumipes in urban areas show that some species benefit from the habitat changes associated with urbanization" lead researcher from the University of Sydney, Elizabeth Lowe said. "Our results also highlighted the importance of incorporating environmental variables from multiple scales when quantifying species responses to landscape modification."

As natural predators, spiders are extremely good moderators that keep insect populations at bay. And in spite of the bad publicity they receive, researchers say that this species is in fact a friend to man.

Found to be particularly abundant, and rather enlarged in areas of high socioeconomic status, the research team attributed the morphological differences in these groups of spiders to two like urban environmental changes-heat and prey availability. As increased temperatures of paved roads and buildings help effect the spiders' growth, light pollution and wastes from urbanization help to feed the growing spiders by driving prey species their way. Creating ideal microhabitats, these urban environments may provide environmental changes beneficial to the species, but the researchers suspect that the species would do just fine in their absence.

"N. plumipes may be pre-adapted to become an urban exploiter, as Nephila are often edge dwellers and can reach large abundances under suitable conditions such as high prey availability" Lowe said. "Other web weaving spiders are also know to thrive in urban environments and it is likely they are responding to similar modifications to the natural environment."

Continued research into the effects urbanization has on native species' population density and biodiversity will be necessary to define the entire ecological system of the south eastern Australian shore, however, for now Australians can rest at ease knowing that spiders are thriving and keeping insect populations low... just sleep with one or two eyes open.