Variation in eastern wild turkey nesting phenology at their northern range limit

Limiting the potential for disturbance of wild turkey (Meleagris gallopavo) breeding and nesting is often stated as a concern for management, particularly when associated with the spring hunting season. The timing of wild turkey nesting has been shown to vary with latitude, with spring phenology, and among individuals, but local information on nesting timing is needed to fully evaluate local harvest regulations. Our objectives were to characterize wild turkey nesting phenology and identify overlap with current hunting season timing and hunter effort in Maine, USA. We also identified sources of variation related to land cover and individual female characteristics such as body condition and pathogen infection status. Finally, we compared the temporal distributions of nest initiation across the 2 years of our study. We assessed nesting phenology of eastern wild turkeys (M. g. silvestris) in Penobscot, Hancock, and Cumberland counties, Maine, by monitoring females for nesting activity using VHF and GPS transmitters. During April-July 2018 and 2019, we located 69 nests from radiomarked females and 3 nests from unmarked females. Of the nests discovered, 56 were presumed first attempts, 12 were second attempts, and one was a third attempt. The median date of nest initiation (i.e., date first egg was laid) for first nests was April 27 in 2018 and May 5 in 2019. Females that nested in areas with greater residential and urban development initiated nests earlier than females that used more rural agricultural land covers. Despite a delay in the onset of nesting in 2019, the distribution of nest initiation among females did not change throughout the season. Our results indicate that the majority of male harvest occurred concurrently with egg laying. Thus, current hunting season timing likely limits risks associated with disturbance of mating. Given that Maine's wild turkey population is thought to be stable or increasing, our data support maintaining the current hunting season structure. However, breeding and nesting phenology of wild turkeys should continue to be monitored in relation to changing environmental conditions, trends in the turkey population, hunter numbers, and spring harvest, so that future changes can be incorporated into harvest management and decision making.