Land or sea? Foraging area choice during breeding by an omnivorous gull

Table 3 Summary statistics for GLMMs to look at field characteristics and temporal influences on the probability of lesser black-backed gulls being present on agricultural fields (observations = 300, n fields = 50, n transects = 10). We then tested for associations between lesser black-backed gulls and the number of birds of -other gull species (all gulls excluding lesser black-backed gulls), −waders (lapwings and oystercatchers), and the number of earthworms; by including these terms along with the best fit model (9). All models included field nested within transect as a random effect. Akaike information criterion adjusted for small sample sizes (AICc), change in AICc relative to the best-fit model (9) and marginal R² (R²m) and conditional R² (R²c) values are presented

	Model	d.f.	AICc	∆AICc	R²m	R²c
1	day	4	144.1	36.5	0.002	0.55
2	intercept	3	142.3	34.7	-	0.54
3	crop + veg.height + veg.cover	11	121.9	14.4	0.82	0.95
4	crop + veg.height	8	118.1	10.5	0.86	0.95
5	obs.per + day	6	117.9	10.3	0.11	0.92
6	veg.height + veg.cover	7	117.1	9.52	0.83	0.94
7	obs.per	5	116.3	8.73	0.11	0.92
8	veg.height	4	110.9	3.32	0.83	0.94
9	veg.height + obs.per	6	107.6	0.00	0.74	0.89
10	model 9 + earthworm	4	109.7	2.09	0.74	0.89
11	model 9 + waders	4	104.8	−2.80	0.77	0.88
12	model 9 + gulls	4	83.9	−23.6	0.77	0.96

crop = crop type, day = morning/evening, earthworm = number of earthworms, gulls = number of other gulls, obs.per = observation period, veg.cover = vegetation cover, veg.height = vegetation height, waders = number of waders (lapwing and oystercatcher)
Selected model (9) is indicated in bold

ISSN: 2051-3933