Citizen science is increasingly recognised as one of the most cost-effective means of achieving large-scale and long-term biodiversity monitoring. We’re quite familiar with this concept for birds and butterflies, but what about for habitat? Historically, changes in habitat or land cover in the UK have been recorded through two main approaches: professional field data collection and remote sensing using satellites. Both have major limitations: field surveys are costly and can only cover small areas, whereas remote sensing can cover the whole country but with less detail and greater uncertainties. BTO scientists were keen to see if habitat data collected by volunteers for the Breeding Bird Survey (BBS) could contribute to understanding how habitats have changed. Over 2,500 BBS volunteers have recorded the habitats along their survey transects since 1994, from city centres to mountain tops. These data were used to quantify change over time in the reporting of different habitats in the British countryside. Increases in woodland cover were detected, in particular, mixed woodland, and declines in farmland cover, particularly livestock farming were also found. Whilst the estimate of habitat area matched existing data well, estimates of habitat change did not. These results are encouraging considering that habitat recording on BBS was not designed for the purpose of habitat monitoring. This work shows that volunteers can play a significant role in monitoring of habitats provided clear protocols are followed that have been designed with habitat monitoring in mind.

Woodcock, along with many other woodland bird populations, have been in long-term decline. Habitat change has been indicated as a possible cause for some species, but evidence is sparse for others, including Woodcock, due to an incomplete knowledge of their habitat requirements, which we can now examine. National BTO/GWCT Woodcock surveys undertaken in 2003 and 2013 provided data from 807 and 823 randomly selected 1 km squares, respectively. Woodcock counts were compared with a range of landscape-scale habitat variables as well as local habitat measures recorded by surveyors, using generalised linear mixed models. Habitat variables were measured at a variety of spatial scales using ring buffers, however high correlation between scales limits interpretation. The results show that, at large landscape scales, breeding Woodcock abundance was correlated with total woodland area and woodland type. Woodcock were more abundant in woods containing a more heterogeneous mix of woodland habitat types and in woods further from urban areas. On a smaller spatial scale, Woodcock were less likely to be found at sites dominated by Beech and more likely to occur in woods containing Birch. The Woodcock’s association with large, heterogeneous woods and the apparent attractiveness of certain woodland types present the most relevant topics for future research into the role of habitat change in long-term declines.

Although we have lost over three-quarters of the UK Cuckoo population, we are unsure of the causes of this decline. Alongside this, the strong divide in northern and southern populations of Cuckoo and their local trends are cause to question why the local differences arise. This study, led by PhD student Chloe Denerley and using BTO's BBS data, used local data from Devon in comparison against data on Cuckoos and their hosts, habitats, and prey items. In Devon, Cuckoos were more likely to be found in areas with semi-natural habitat and more Meadow Pipits (but fewer Dunnocks) and with a higher number of moth species, which are predated by Cuckoos in late summer. Across the UK, Cuckoos have become more associated with upland heath with Meadow Pipits, and with wetland habitats with Reed Warblers, and the distribution of Cuckoos shifting from south to north within the UK. The abundance of moth species preyed upon by Cuckoos has declined four times faster than that of other moths. Overall, the results suggest that Cuckoos have contracted out of the farmed countryside and into heathlands and the uplands. Coordinated monitoring of moth, host and Cuckoo numbers across such projects could tell us much about the long-term prospects for reversing Cuckoo population decline in the UK

Public data archiving (PDA), where data are made freely available on demand through recognised data repositories, is increasingly being required by funders and journals to promote ‘open data’. However, this rapidly developing area brings with it some potential risks, particularly to the maintenance and operation of long-term citizen science monitoring schemes. What are the solutions?

Waterbirds in the UK presents the summarised results of the annual WeBS report, and full data available via the WeBS Report Online. It provides a single, comprehensive source of information on the current status and distribution of waterbirds in the UK for those interested in the conservation of the populations of these species and the wetland sites they use.