Fig. 5
From: Land or sea? Foraging area choice during breeding by an omnivorous gull
Main effects of gulls’ presence on agricultural fields 2013. a Main effects terms for model 9 (Table 2), showing the factors affecting the probability of lesser black-backed gulls being present on agricultural fields during the study period in 2013. Coefficients and 95 % confidence intervals (Wald estimates) are shown for the standardized model allowing direct comparison of effects between variables. These are compared to study period 1 during 2013. b Boxplot showing the negative relationship between vegetation height and lesser black-backed gull presence on agricultural fields during the observation period in 2013. Boxplot shows medians (horizontal line), approximate 95 % confidence intervals of medians (notches), 25th and 75th percentiles (boxes), the most extreme data point that is no more than 1.5 times the length of the box away from the box (whiskers), and outlying observations beyond these (circles). c Bar chart showing the decrease in gull presence on agricultural fields during the observation periods (beginning, middle, end) in 2013