The effect of orientation must also be discussed. The experiment forest edge is east facing, suggesting the edge receives most of its insolation in the morning. Previous studies on the effect of orientation on edges focus on North-South orientation, and current understanding suggests orientation will not exaggerate edge effects.
There may also be a temporal effect, as the study was only carried out for 2 weeks post-Spring, where U.K. bird populations are near their peak \cite{defra2018}. Previous studies in Scotland have shown significant seasonality in nest predation rates around spring. Nest predation rates were shown to peak in late April, and then slowly decline until late June \cite{Malzer_2015}. If this seasonal predation effect is also seen in England, it may help account for the unusually high levels of predation seen in this experiment. However it should be noted that although Malzer & Helm found an overall effect of season on nest predation, it did not influence the edge effect, which was constant year round.