Appendix 3.

Body mass (g) of Great Black-backed Gull. Data shown as mean (range).

Location	N. Europe Barents Sea	Ram I., MA (1)	National Wildlife Refuge, Monomoy, MA (2)
Source	Dunning 1993	P. Cavanagh unpubl. data	M. Teets unpubl. data
n (male/female)	116/93	3/29	19/18
Body mass
Male	1,829 (1,380–2,272)	1,784 (1,716–2,050)	1,747 (1,500–2,100)
Female	1,488 (1,033–2,085)	1,492 (1,299–1,655)	1,483 (1,200–1,700)

(1) Culled on 15 May 1990; mass may not be representative, because of water retention from ingestion of DRC–1339. (2) Mass measured after birds were frozen and thawed.