CBC sample sizes did not allow monitoring of House Sparrows until 1976; previously, there had been many farmland plots with high populations that could not be properly quantified without better access to farm buildings and housing. CBC/BBS data indicate a rapid decline in abundance over the last 25 years, as does the BTO's Garden Bird Feeding Survey (Siriwardena et al. 2002, Robinson et al. 2005b). These results are supported by many other data and anecdotal reports, and have generated great conservation concern (see Summers-Smith 2003). A change in the listing criteria has resulted in the admission of the species, green-listed until 2002, to the red list. A temporary drop in first-year survival coincided with the steepest decline, but changes in breeding performance, especially nest failure rates at the chick stage, have also helped drive population change (Freeman & Crick 2002). Possible explanations include a general reduction in food supply, less grain being spilt during agricultural operations, tighter hygiene regulations, increases in predation, and toxic additives to unleaded petrol (Siriwardena et al. 2002, Robinson et al. 2005b, Summers-Smith 2007). The overall national decline since the 1970s masks much heterogeneity by region and habitat, and population processes may be relatively fine-grained: overall, populations in rural areas had declined by 47% by 2000, and those in urban and suburban areas by about 60% (CBC data: Robinson et al. 2005b). BBS suggests increases recently in Scotland and Wales. Overall, brood size has decreased, but nest success has improved markedly. Following widespread declines across Europe during the 1990s, the European status of this species is no longer considered 'secure' (BirdLife International 2004).

Population changes

Productivity trends

Additional information

• Maps and statistics from British and Irish atlases
• BirdFacts page on species biology
• BirdTrack results
• Garden BirdWatch results