How your BBS counts make a difference

Every year, thousands of BBS surveyors dedicate valuable time to collecting the data from which the BBS trends are derived. Combined with data from the Common Birds Census (CBC), which ran from 1962 to 2000, this has allowed us to track the fortunes of our common breeding birds for over four decades. Here we give an overview of how such monitoring plays a pivotal role in the modern conservation process.

The figure below illustrates the ‘conservation loop’ – the process by which conservation organisations both governmental and non-governmental ensure that resources are used in most efficient way. Strong monitoring underpins this loop; the BBS is one of a range of schemes that cover nearly all the regularly occurring species in the UK. 

The conservation loop (Corn Bunting by Mark R Taylor)

Monitoring. The large sample size of the BBS means that reliable population trends can be produced for a large number of species. This detailed information allows us to track changes in numbers over the short term, medium term (since the scheme started in 1994), and the long term, when combined with CBC data. These trends, together with data from other monitoring schemes, feed into setting conservation priorities…

Setting conservation priorities. Initiatives such as Birds of Conservation Concern 3, which produced new Red, Amber and Green lists for the UK’s birds, rely on good-quality bird trends to make appropriate assessments. These lists are then used by conservation organisations to identify which species should be the target of conservation efforts. In recent years, this has meant a continued focus on declining farmland birds (e.g. Turtle Dove, Corn Bunting and Yellow Wagtail), a growing focus on woodland birds (Lesser Spotted Woodpecker, Willow Tit and Nightingale), and a rising concern for a wide range of trans-Saharan migrants such as Cuckoo, Wood Warbler and Spotted Flycatcher. Not all priorities are species-led, as similarities across trends may lead to a focus on particular habitats, or on issues that cut across many species and habitats, such as climate change.

In addition, monitoring results are invaluable for communicating the state of our bird populations to many different audiences, from the general public to government ministers, and can be used as indicators of environmental health.

Research. Before we act to slow, halt and finally reverse declines, we need to determine what is causing them, and identify how to tackle the problem. This may include analysing demographic data, such as the information gathered by the BTO’s Nest Record Scheme and Constant Effort Sites Scheme. In some cases, new field research may be required to find out more about the ecology of species, such as the joint BTO–RSPB ‘Out of Africa’ project, which aims to increase our knowledge of migrants on their wintering grounds. Eventually we hope to isolate the factor, or factors, driving the declines of priority species. The second stage of research may involve testing solutions to the problems using experimental field trials. A typical example would be manipulation of agricultural habitats to increase food resources, or provide nesting cover, which would be tested by comparing the densities and breeding performance in experimentally ‘improved’ areas with unchanged control sites. Once we know what works, we move to conservation action…

The planning and delivery of effective conservation action ranges from reserve acquisition and management to lobbying government on policy and legislation. Fine-grain monitoring results, such as regional BBS trends, and data collected by the Bird Conservation Targeting Project (used to direct agri-environment action), help us to focus our efforts on the areas where it is needed. Finally, this leads us back to monitoring, which allows us to assess the success, or otherwise, of our conservation action. If we’ve got it right – the right action, in the right places, and enough of it – then future BBS monitoring should reveal positive responses.

By Dr Mark Eaton, Principal Conservation Scientist in Species Monitoring and Research at the RSPB