Conclusions There was no significant difference in deer activity at night and day or between lunar cycles. Deer may have a weak tendency to be more active during intermediate light levels (quarter and three quarter moon). Factors such as predation, human interaction, and decreased light may all be important. There was a significant lack of pictures in the months of April and May. This may be due to fawn births. The activity of this deer population may be more dependent on other factors such as temperature and weather. Introduction Mammals base their circadian rhythms on several factors such as daylight, temperature, predation, and human interaction. Desert mule deer had low diurnal and high nocturnal activity in periods of insect harassment (Hayes and Krausman 1993). Turner (1980) found that Roe deer, in Switzerland, had no significant difference in activity with lunar cycles. In Florida, hunting of white-tailed deer significantly increases their nocturnal activity (Fritzen et al. 1998). Lunar conditions, such as moon phase, may have a direct influence on nocturnal activity. In Iowa, white-tailed deer behavior was dependent on factors such as wind and not lunar phase (Zagata and Haugen 1974). Surprisingly, studies that made conclusions about lunar effects on white- tailed deer activity have not been fully based on nocturnal observations. LITERATURE CITED Fritzen, D.E., Kilgo, J.C. and Labisky, R.F Influences of Hunting on the Behavior of White-Tailed Deer: Implications for Conservation of the Florida Panther. Conservation Biology 12: Hayes, C.L., and Krausman, P.R Nocturnal Activity of Female Desert Mule Deer. Journal of Wildlife Management 57:897. Turner, D.C Multi Variate A2nalysis of Roe Deer Capreolus capreolus Population Activity. Revue Suisse de Zoologie 87: Zagata, M.D. and Haugen, A.O Influence of Light and Weather on Observability of Iowa Deer. Journal of Wildlife Management 38(2): Questions 1)Is there a difference in nocturnal and diurnal activity in deer? 2)Does the lunar cycle (moon phase) have an effect on nocturnal activity of deer? Materials and Methods ACKNOWLEDGMENTS We would like to thank Jeremy and James Ambrosius and the Grove family for allowing us to use their land for our study. Results Effect of Lunar Cycles on Nocturnal Activity of White-tailed Deer in South Central Pennsylvania Ryan Hunsicker, Jordan Grove, and Bradley Rehnberg Department of Biological Sciences York College of Pennsylvania Four infrared trail cameras were placed on private land with known deer populations in Southern York County of Pennsylvania. Two cameras were placed on food plots and the other two were placed in transition areas. Previous knowledge of white-tailed deer eating habits and travel paths were used to place the cameras. SD memory cards were used to collect photos for uploading. Figure 1. Comparison of deer activity for two seasons in Summer includes the months of June, July, and August. Fall includes the months of September, October, and November. Error bars represent one standard deviation. A Mann-Whitney test showed no difference in day and night pictures in either season, p = for fall and p = for summer. Figure 3. Deer sightings on nights that are two days before and after a given moon phase for the year study. NM is new moon, QM is quarter moon, FM is full moon, and TQM is three quarters moon. Error bars represent one standard deviation. A one-way ANOVA found no significant difference in activity between the moon phases, Kruskal-Wallis test p = Figure 4 Deer sightings on a 24 hour time scale for the month of October 2008 and November Sightings after sunset and before sunrise are night sightings, and sightings in between are day sightings. Moon phase is also represented with four distinct stages for that month. Figure 2. Comparison of deer activity for two seasons in 2008 and Winter includes the months of December, January, and February. Spring includes the months of March, April, and May. Error bars represent one standard deviation. A Mann-Whitney test showed no difference in day and night pictures in either season, p = for winter and p = for spring.