Abstract
The Banana Spider, Nephila clavipes, is the largest non-tarantula spider species and commonly colonizes urban habitats. This species is an orb weaver, relying on trapping aerial prey in its large vertically oriented webs. Many nocturnally active insects are attracted to light sources found throughout urbanized areas. I hypothesize N. clavipes exposed to higher light levels in urban areas will be larger than individuals in darker natural areas. Forty nine spiders were observed and recorded; twenty four in natural areas and twenty-five in urban areas. For each spider the following was recorded: GPS coordinates, web height and diameter, size of female, lumen exposure and distance to the light source and the number of males and kleptoparasites on each web. All data was collected an hour after sunset to ensure that natural sunlight would not confound the data collection. The urban sites include Nova Southeastern University, Broward College, and a highly populated street parallel to Hollywood Beach. The natural sites included: Fern Forest Natural Area, Tree Tops Park and John U. Lloyd State Park. The results show there is a highly significant statistical difference in mean spider size (p=0.000001089). N. clavipes found in urban environments had a mean size of 2.93 ± 0.11 inches, while in natural environments they had a mean size of 1.91 ± 0.15 inches. There was a weak correlation between spider size and distance to light source, as well as lumen exposure, indicating other factors may be contributing to the size differences noted in addition to light.
Faculty Sponsors
Dr. Paul Arena
Project Type
Event
Location
Alvin Sherman Library
Start Date
4-8-2016 1:00 PM
End Date
4-8-2016 5:30 PM
Shedding Light on Banana Spiders in Urban Habitats
Alvin Sherman Library
The Banana Spider, Nephila clavipes, is the largest non-tarantula spider species and commonly colonizes urban habitats. This species is an orb weaver, relying on trapping aerial prey in its large vertically oriented webs. Many nocturnally active insects are attracted to light sources found throughout urbanized areas. I hypothesize N. clavipes exposed to higher light levels in urban areas will be larger than individuals in darker natural areas. Forty nine spiders were observed and recorded; twenty four in natural areas and twenty-five in urban areas. For each spider the following was recorded: GPS coordinates, web height and diameter, size of female, lumen exposure and distance to the light source and the number of males and kleptoparasites on each web. All data was collected an hour after sunset to ensure that natural sunlight would not confound the data collection. The urban sites include Nova Southeastern University, Broward College, and a highly populated street parallel to Hollywood Beach. The natural sites included: Fern Forest Natural Area, Tree Tops Park and John U. Lloyd State Park. The results show there is a highly significant statistical difference in mean spider size (p=0.000001089). N. clavipes found in urban environments had a mean size of 2.93 ± 0.11 inches, while in natural environments they had a mean size of 1.91 ± 0.15 inches. There was a weak correlation between spider size and distance to light source, as well as lumen exposure, indicating other factors may be contributing to the size differences noted in addition to light.
