Abstract
Typically, urbanization leads to habitat destruction and negative effects on the success of native species, however generalist predators like spiders may be exploiting these areas. Urban habitats tend to be warmer (due to the heat island effect), harbor an abundance of light attracted prey species and contain reduced densities of large native predators (bats and birds) when compared to natural areas. These attributes may provide Nephila clavipes, the Golden Orb Weaver, with an optimal habitat which enhances their overall productivity. I examined the effects of increasing levels of urbanization on body size and fecundity of N. clavipes. I hypothesized this species may be an urban exploiter and that individuals would be larger and more fecund in urban areas when compared to natural areas. Sample sites were categorized under three different location classifications based on magnitude of urbanization: Urban, Urban Parks and Rural. Morphological and physical data were collected and lipid concentration was determined using a bioassay as a measurement of fecundity. Overall, urban spiders were significantly larger (p<0.05) than both park and rural spiders, supporting the notion that this species benefits from urban habitats. Lipid analyses were inconclusive, likely attributed to the effect of egglaying on female lipid content. Previous research has generally focused on the negative aspects of urbanization on animal welfare, however, this study provides evidence suggesting that some species might benefit from these environmental changes.
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
Urbanization Effects on Size and Fecundity of Nephila clavipes
Alvin Sherman Library
Typically, urbanization leads to habitat destruction and negative effects on the success of native species, however generalist predators like spiders may be exploiting these areas. Urban habitats tend to be warmer (due to the heat island effect), harbor an abundance of light attracted prey species and contain reduced densities of large native predators (bats and birds) when compared to natural areas. These attributes may provide Nephila clavipes, the Golden Orb Weaver, with an optimal habitat which enhances their overall productivity. I examined the effects of increasing levels of urbanization on body size and fecundity of N. clavipes. I hypothesized this species may be an urban exploiter and that individuals would be larger and more fecund in urban areas when compared to natural areas. Sample sites were categorized under three different location classifications based on magnitude of urbanization: Urban, Urban Parks and Rural. Morphological and physical data were collected and lipid concentration was determined using a bioassay as a measurement of fecundity. Overall, urban spiders were significantly larger (p<0.05) than both park and rural spiders, supporting the notion that this species benefits from urban habitats. Lipid analyses were inconclusive, likely attributed to the effect of egglaying on female lipid content. Previous research has generally focused on the negative aspects of urbanization on animal welfare, however, this study provides evidence suggesting that some species might benefit from these environmental changes.
