Effects of the urban heat island on anurans in remnant and stormwater control ponds in the Charlotte Metropolitan Region

The urban heat island (UHI) has been documented to increase urban air temperatures compared to rural areas, but little is known about the effects of UHI-induced meteorology on anuran breeding and diversity. My research objective is to understand how the meteorology associated with an UHI affect the breeding activity and diversity of anurans. Twelve evening call surveys were conducted at 66 ponds in the Charlotte Metropolitan Region to assess anuran breeding activity. To account for meteorological conditions, air temperature and relative humidity at ponds both breeding seasons are recorded and monthly average rainfall and average temperatures for each landscape are measured. To account for variation in local habitat quality and landscape composition in 2014 and 2015, pond descriptors and vegetation in and around each pond are measured, as well as the proportions of landscapes covered by forest and agricultural, wetland density, and road density. Landscape variables are quantified for 13 concentric scales ranging from 0.5-20 km of each pond. Occupancy analysis and generalized linear modeling is used to assess the effects of meteorological variables on occupancy and detectability of individual anuran species and on anuran species richness. There was no evidence to support that the UHI alters anuran species richness. However, there is evidence that the UHI may alter species occupancy and detectability at ponds. Thus, as UHIs continues to increase in magnitude, breeding activity of some species is likely to be altered from effects of the UHI.