Fig. 6

Effect of backpack treatments on posterior wing abrasion. Fitted curves (± SE) for effect of backpack treatments on posterior wing abrasion. Abrasion was scored on a Likert scale with one being no abrasion and higher values indicating increasingly severe abrasion. Grey dots are weighted by number of birds. Red dots, also weighted by number of birds represent severe cases (Abrasion scores of 3 or 4). There was no effect of sex