Scientific papers

Data from the GBFS has formed the basis of several peer-reviewed scientific publications. These highlight the value of this survey as a scientific resource. In our urbanising world and with wild bird care products continuing to be developed apace, the value of the GBFS for research purposes will continue to grow.

Charting populations

Ibis (2005) 147: 563-575

Twenty one species have shown significant increases in their occurrence at garden feeders between 1970 and 2000. Moreover, in several species GBFS counts correlate strongly with relative population size during the previous breeding season. Therefore, the GBFS can provide an indication of changes in bird populations at large. Find out more >>>

Feeding frenzy

Bird Populations (2006) 7: 212-215

The scale of bird feeding is now enormous, with some 60 thousand tonnes of bird food provided annually in the UK. The GBFS has charted birds coming to our feeders and bird tables as the scale of this provision has increased. Find out more >>>

Boom and bust

Bird Study (2007) 54: 120-126

An important natural food of birds during winter is the seed of beech trees, known as ‘beechmast’. In some years, so called ‘mast years’, beechmast is abundant in the countryside, whereas in other years it is relatively scarce. When the latter occurs, GBFS data show that several species use food supplements in gardens in greater number. These include Great-spotted Woodpecker, Woodpigeon, Great Tit, Coal Tit, Nuthatch, Jay and Chaffinch. Find out more >>>

Sparrowhawks make a comeback

Journal of Ornithology (2009) 150: 247-254

Organochlorine pesticides decimated the UK Sparrowhawk population in the 1960s so at the start of the GBFS this species was a rare sight in gardens. Changes in farming practices enabled Sparrowhawks to recover and their increase in number coincided closely with the 40 years of the GBFS. Most (53%) GBFS participants now see at least one Sparrowhawk in their garden during winter. So, what effect has this increase had? Could it have driven the decline of some garden birds? GBFS data suggest that in most species there is little evidence that the re-colonisation of this agile predator has driven long-term population declines. Find out more >>>

New statistical methods

Biometrical Journal (2015)

Many datasets have a spike in the number of observations at zero – i.e. where the observer didn’t see the species during the study period – which can make the data difficult to analyse. Researchers at the University of St Andrews used the GBFS dataset to address this, by developing a new statistical modelling approach. They also investigated how this method might allow a more robust examination of the interaction between Sparrowhawks and their songbird prey at garden feeding stations. This worked well and revealed some interesting patterns, most notably a correlation between the abundance of House Sparrows and their Sparrowhawk predators. Find out more >>>