Carolina Wrens, Thryothorus ludovicianus, are permanent residents throughout their range. They form pair bonds at a young age, maintain these bonds for multiple years, and defend feeding/breeding territories year round. Male Carolina Wrens use songs in territorial defense and have been shown to countersing regularly to both neighbors and intruders. They use various song characteristics to determine the location of another bird and whether its territory has been invaded. Wrens often approach playbacks silently in apparent searching behavior. In some cases, birds will investigate the playback but fail to countersing. I wanted to determine whether or not wrens would respond more strongly during playbacks with a decoy. In addition, the experiment was conducted during breeding and nonbreeding periods to compare responses across seasons. The findings show that wrens respond more aggressively to playbacks with a decoy and to playbacks conducted during the breeding season.

As the earth’s landscape becomes increasingly urbanized, local wildlife must adapt to urban conditions or migrate to areas that are more rural. Urban wildlife face challenges such as direct loss of habitat, competition with non-native species, disturbance due to anthropogenic noise, and micro-climatic changes. Factors such as temperature, relative humidity, and noise affect the acoustical environment and may affect the ability of many animals, including birds, to communicate. Understanding how urbanization affects birds’ singing behavior is critical because singing often plays a vital role in attracting mates and defending territories. In addition, as global climate change occurs it will become increasingly important to understand the influence of abiotic factors such as temperature on the singing behavior of birds. Developing a deeper understanding of how those abiotic factors affect singing and other associated behaviors may help guide future conservation actions. Carolina Wrens are often used to study the role of singing in defending territories. They are also a common subject for ranging studies. However, surprisingly little research has been conducted on the factors influencing Carolina Wren song activity over the course of a day. No studies have compared the singing activity of Carolina Wrens in urban and rural environments. The purpose of this study was to compare the singing activity of Carolina Wrens in urban and rural areas. Specifically, this study looked for patterns in the timing of songs throughout the day and examined the effects of season, temperature, and anthropogenic noise on singing activity in urban and rural settings. I analyzed data from 4 SongMeter© SM2 data loggers (2 located at an urban park in Bowling Green, KY and 2 located at a rural preserve in Hart County, KY). The data loggers were programmed to record ambient sound for 3 minutes at the beginning of every hour. A Hobo® data logger was deployed with each SongMeter© SM2 data logger to record temperature and relative humidity at 15-minute intervals. One week of data in May and one week of data in July were analyzed. Both weeks had similar photoperiods, temperatures, and amounts of precipitation. For each recording, I documented the number of Carolina Wren songs I heard and a categorical assessment of the precipitation and anthropogenic noise due to traffic or machinery. I conducted Chi-square analyses to compare the seasonal or site-based observed frequencies of singing activity to the corresponding expected frequencies. In May, Carolina Wrens at the urban site sang more than their rural counterparts. Daily activity patterns were visually analyzed using the average number of songs detected for each hour’s sampling period. No Carolina Wrens were heard singing the hour before sunrise or the hour after sunset. In May, the dawn chorus lasted nearly twice as long as in July. Zero-inflated Poisson regressions were used to determine the correlations between Carolina Wren singing activity and temperature or anthropogenic noise. Carolina Wren singing activity had significant correlations with both variables.