You never know what's in store with the Breeding Bird Survey ...


... well, in most years you might.

But in 2016, I had a Purple Heron fly right over my head during my Breeding Bird Survey* (BBS) on a Hertfordshire square last year. I can almost hear my mates sighing as they read this — 'not this story again' — but I've got to enjoy it while I can! This was followed by a singing Turtle Dove on my inland Norfolk square for the first time, so I'm pretty sure I won't get another year of BBS like that again. It does go to show though: anything can happen when you're out in the field, even on two randomly selected BBS squares.

This isn't the reason I take part in the survey. Of course, it's a great excuse to get out birding, and it's only two bird surveys — plus a recce visit — per square each year. I'm finished by 9 am and free to ... go to work, or even better, do some more birding! I'm not expecting to make a discovery every time I set foot on my BBS square; for the Hertfordshire square, it was the first time I covered it, so a little bit of me hopes it'll always 'produce' — but I doubt it! In any case, I know I'll enjoy doing the survey and simply being out in the field.

Sarah was fortunate enough to find this Purple Heron during her BBS in 2016 (Photo: Jason Ward)

The real reason I take part is because I know these records are needed. They are needed to produce robust population trends for our common and widespread breeding birds, needed to calculate population estimates and needed for use in research. In turn, these analyses provide the facts for decision-makers, measure progress and help to direct future research. Without the army of over 2,700 skilled volunteers collecting these data on over 3,700 randomly allocated squares, we would not have the long-term population trends for 111 UK bird species and huge dataset — thank you to all who are already involved.

Going back to Turtle Dove, the Breeding Bird Survey has recorded a decline of 93 per cent in the UK since the survey began in 1994. This is the largest decline of all the species monitored by the BBS and a trend which is mirrored across Europe. Agricultural change here in the UK, changes in the wintering grounds of West Africa and hunting pressures during migration are thought to be contributing to the decline of this species, with the addition of trichomonosis — a disease better known as contributing to the 39 per cent Greenfinch decline in the UK between 1995 and 2014 — being detected in Turtle Dove recently. Thankfully, we have the population trend information to support the need for continued research and conservation work.

To help us monitor our common and widespread breeding birds with the BBS, you need to be able to identify the species you are likely to encounter on your square by sight and sound. Knowledge required will vary depending on the habitats within the square; for example, an upland square is likely to contain fewer species than a lowland woodland, where identification by sound is particularly important. Your Regional Organiser will be able to let you know which squares are available in your area and discuss which would be most suitable. All squares are pre-selected at random to reduce bias with regards to habitats covered, ensuring that the trends produced provide an even representation of the habitats within the UK.

If you would like to find out more, please visit the BBS webpage (www.bto.org/bbs). Once you've had a browse, contact your Regional Organiser by clicking on the 'Sign Up' button on this page and help us collect the information we need to find out more about population changes and in turn, help conserve our breeding birds. Not only this, there is the option of monitoring mammals during the survey, from which we produce population trends for nine mammal species. Squares can also be revisited at a more suitable/sociable hour (midday rather than dawn!) to monitor butterflies for the Wider Countryside Butterfly Survey.

*The Breeding Bird Survey is run by the BTO, in partnership with JNCC and RSPB.

Written by: Sarah Harris, BTO