Assessing broad-scale changes in seabird populations across the North Atlantic requires an integration of available datasets to understand the spatial extent of potential drivers and demographic change. Here, we compared survival of Northern Fulmars Fulmarus glacialis from a Scottish and an Irish colony from 1974 to 2009. Despite lower recapture probabilities of monel-ringed Irish birds compared with colour-ringed Scottish birds, survival probability decreased at both colonies. The extent to which the decline in survival is related to density-dependent processes or other external drivers remains uncertain, but our results suggest that these changes in survival are possibly indicative of larger-scale processes and are not confined to local colony dynamics.