Table 2. Summary of basic information for each population: Means and standard deviations for each trait.

		Wing length		Tarsus length		Mass		Bill length
Species	Population	mean	std dev	mean	std dev	mean	std dev	mean	std dev
Red billed gull	1- Kaikoura, New Zealand	278.13	8.75	443.12	18.95	288.99	26.81	49.83	2.3
Great reed warbler	2- Kvismaren, Sweden	98.33	2.89	33.09	1.03	33.37	2.43	12.51	0.57
Barn swallow	3- Badajoz, Spain	120.52	3.08	11.15	0.53	18.33	1.56	7.53	0.55
	4- Kraghede, Denmark	125.68	2.97	11.18	0.81	19.28	1.52	7.82	0.49
Blue tit	5- Muro, France	61.83	2.02	16.24	0.51	9.71	0.48	9.76	0.48
	6- Pirio, France	62.1	2.05	16.04	0.51	9.31	0.5	9.74	0.45
	7- Rouviere, France	65.92	2.27	16.7	0.52	11.07	0.65	9.86	0.46
Collared flycatcher	8- Gotland, Sweden	81.76	2.19	19.37	0.59	13.68	1.33	13.36	0.82
Savannah sparrow	9- Kent Island, Canada	66.59	2.68	21.07	0.7	19.71	1.62	8.09	0.38
House sparrow	10- Lundy, UK	77.71	2.17	18.55	0.83	27.61	1.86	13.29	0.58

Measurements are in millimetres (mm) and mass in grams (g).