Bird surveys on nature reserves

Bird surveys on nature reserves

Willow warbler singing at Frensham Common nature reserve in Surrey. April 2011. - Chris Gomersall/2020VISION

Find out more about breeding bird surveys on Wildlife Trust nature reserves, what they can tell us, and how to get involved

With the help of a group of dedicated volunteers, we have been monitoring numbers of breeding birds on our nature reserves for many years. If you would like to get involved, read on to find out more about what is involved and see the bottom of the page for how to contact us. 

Our breeding bird surveys involve 6 early morning visits between April and June, walking a fixed route around the site and recording all birds seen and heard on a map. Often it is mostly based on what you can hear, as many of the birds are very good at staying hidden! We also record behavior, e.g. if a bird is seen carrying nest material, or if two males are interacting at the boundary of their territories. We then combine the records from all 6 visits to get an idea of where birds are likely to be holding territories, e.g. a singing male in the same place on each visit.

Blackbird with nest material, sparrowhawk, cuckoo and moorhen feeding chick

Copyright Sian Williams

Obviously these surveys are useful because they provide us with records of the birds themselves, but they can also tell us more about our nature reserves in other ways. For example:

  • They can tell us detail about habitats, since many bird species have particular nesting requirements. For example, some species nest in holes in dead wood. If we record good numbers of these species, it tells us we have lots of standing dead wood on a site, which is also valuable habitat for other organisms such as invertebrates and fungi.
  • They can help us keep an eye on species that are of particular conservation concern, for example red-listed species such as cuckoo or nightingale. Some of our sites have conservation designations (e.g. Site of Special Scientific Interest or Special Protection Area) that are based on the site supporting populations of particular bird species, and we can also use our survey results to check how these species are doing. This helps us to provide feedback on whether management is working for these key species.
  • We can compare trends in how species are doing on our sites with national trends (e.g. thost published by the British Trust for Ornithology). If a decline or increase in a particular species doesn’t match the national trend for that species, that can be a cue for us to look into whether there is something specific to that site that might be affecting the species.
  • We can look at changes in species populations in the long-term, particularly associated with habitat succession. For example at our woodland regeneration sites, as the trees grow, we can track the change from mainly grassland-nesting species such as skylarks and meadow pipits, through scrub-associated birds like willow warblers, and eventually to woodland specialists.

A big thank you to all of the volunteers who help with these surveys, and the office volunteers who help process the data. If you are interested in getting involved in surveys, you will need to be able to confidently identify species by sound - but don’t worry, if you aren’t there yet, you can improve your skills at one of our bird song training workshops. Opportunities for breeding bird surveys come up across the three counties, but at the moment we’re particularly looking for new volunteers in Northamptonshire and Cambridgeshire. If you are interested, please get in touch with us at ecologygroups@wildlifebcn.org