British Trust for Ornithology Surveys

By Harry Green BTO Regional Representative Worcestershire.

BTO surveys in 2001 were severely disrupted by the Foot & Mouth Disease epidemic. Hopefully we shall get back on track in 2002. As readers will know the results of BTO surveys are of the greatest importance in national monitoring of bird populations - whenever you see figures quoted for declines or increases they are nearly always derived from the work of BTO volunteer surveyors. The Breeding Birds Survey (BBS), following on from the old Common Bird Census, is the most important of the long-term monitoring surveys. It is supplemented by the Water Birds Breeding Survey (WBBS) which uses similar techniques along water courses. Other important surveys are the repeat survey of waders breeding in wet meadows in spring 2002, and the Winter Farmland Bird Survey. The following is a review of the various surveys and the situation in Worcestershire.


Winter Farmland Bird Survey

This will be a survey of three full winters 1999-2000, 2000-2001 and 2002-2003 (next winter to replace the season lost to FMD) The aim of this important surveyb is to fill gaps in knowledge of the ecology of farmland birds in winter. It has three components: the randon 1 km survey, Winter Walks, and Casual Records, and the survey is on lowland farmland throughout Britain. The Random Square Survey requires three visits each winter, the others are not limited by location or number of visits required. The Randon Squares covered in Worcestershire match the Breeding Bird Survey squares and ten were surveyed in previous winters. This survey requires detailed visits to farmland and is postponed until next winter, but new observers are welcome to join in the other two surveys which do not required detailed visits to farmland.

Casual Records of farmland birds (recording form available).

This is survey of significant flocks of farmland birds between November and February within certain categories:

100 or more plovers (Golden Plover, Lapwing)
20 or more other waders (Snipe, Curlew)
100 or more thrushes and starlings (fieldfare, song thrush, redwing, mistle thrush, starling)
20 or more partridge or doves (grey partridge, stock dove)
20 or more small passerines (skylark, meadow pipit, pied wagtail, house sparrow, chaffinch, brambling, greenfinch, goldfinch, linnet, redpoll, bullfinch, yellowhammer)
all scarce passerines (woodlark, stonechat, tree sparrow, twite, snow bunting, reed bunting, corn bunting).

Winter walks recording farmland birds (recording form available).

Observers simply record the species seen using fields, hedges and farmland habitats adjacent to a route which is walked regularly between November and February. Every time you do the walk you collect records. Route chosen by observer and should be at least 1km long.

I have not seen all the records collected by these surveys in previous winters in Worcestershire but I know that several observers have contributed. If anyone wants to take part please ask for recording forms.

Pilot Winter Mammal Monitoring Survey

For more information on this see elsewhere in this newsletter under the Worcestershire Mammal Atlas project.

Waterbirds Breeding Survey

This is basically a transect-style survey along a waterway randomly selected in tetrads (2x2 km squares) of the national grid. The methods used are similar to the BBS (see later). We have three surveys running in Worcestershire: two on the River Teme and one on the Worcester-Birmingham Canal. BTO are probably going to ask for more sites in 2002 so more volunteers may be required.


Breeding Waders in Wet Meadows

We have a large number of sites in Worcestershire along the main river valleys.. The method is to visit the sites three times between mid-April and the end of June with at least two weeks between visits. Each visit should preferably be between dawn and midday. The areas need to be covered systematically and waders seen are recorded on maps provided. This survey was postponed from last spring. I have no observers so far and we badly need help, although I hope for help in the south by Mike Smart and his team from Gloucestershire. Any offers of help would be welcome - please contact me as soon as possible.

Birds on Lowland Grassland

I have little information about this survey in Worcestershire although I gather three surveyors of BBS squares were contacted by BTO on some aspects. However, I have three sets of forms for the postponed 2001 summer survey and hopefully they will be used to complete the work in summer 2002 as an adjunct to BBS survey. The aim is to assess the sue of grasslands by birds in summer.

Peregrine Survey

This is mainly organised by the Raptor Study Group and peregrine enthusiasts and aims to check existing, past and potential breeding sites in a repeat of earlier surveys. It was postponed last year but should go ahead in spring 2002. We do have a local enthusiast who will (hopefully) visit Worcestershire sites. However, peregrines are about in the county and if anyone locates breeding birds I should be grateful if they could get in touch with me. Any information given to me will be treated in confidence. We look forward to the first records of breeding birds on buildings or pylons!

Breeding Birds Survey

This continuing annual survey is most important in monitoring breeding birds throughout UK. It is now based on around 2,400 randomly selected 1x1 km squares of the national grid throughout Britain. We have 51 squares in Worcestershire. These have been well-covered in previous years but the survey could not go ahead in 2001, although seven Worcestershire squares were covered in places safe from FMD: four in Wyre Forest, one in Worcester city, and two in suburban Birmingham. The main methodology is to walk two transects in a 1x1km square recording the birds on special forms, and collecting data on habitat. Once a route is established this is usually achieved by two visits between April and mid-May, and between mid-May and end of June. For a new square an early visit is need to plan the route. To me this is our most important on-going survey . I hope we can pick up the full coverage again in 2002. I know that a few observers will not be able to continue so I do need need observers. If you would like to join please get in touch with me as soon as possible. I have squares available in different parts of the county.

Heronries Census

We have two known heronries in Worcestershire (one just N and one just S of Worcester) and Shaun Micklewright is the count organiser. If you become aware of herons nesting elsewhere please get in touch with me as soon as possible. The British Heron Census is the longest running bird census in the world spanning about 75 years of counts.

Garden Birdwatch

This survey has been running for five years and we have over 100 counters in Worcestershire and about 15,000 nationally. Although quite simple in concept it is providing some fascinating information about the numbers of birds visiting gardens and the timing of their visits throughout the year. Participants receive their own newsletter and special recording forms. If you are interested I can provide a leaflet giving further information.

New Projects

Migration Watch

Starting 1st March 2002 Migration Watch is a web-based project which will trackspring migration through the country. The idea is that bird watchers will submit their daily records using specially designed, simple to use forms on the BTO web site. These can be sent from any regularly watched site. Migration will be tracked through the country. If you don't have a computer, try web access at a library or school, or ask a friend! There are introductory pages on the BTO web site at It will be updated regularly and it is hoped that observers will register their interest in early February. When the project is up and running you will be able to see daily-updated maps on the web site showing various species moving through the country. This is a new and novel approach to the study of bird migration and I urge you all to join in!

BTO London Bird Project

This is a survey to discover exactly what birds use London's green spaces and is a very exciting project, though not to Worcestershire-based observers!


There is no official nightingale survey in 2002 but I am always pleased to received information on singing birds. Hopefully a phone-in recording system will again be available through Worcestershire Wildlife Trust (01905 754919).

The data collected over the last few years, including the 1999 BTO survey, is being used to prepare a leaflet encouraging landowners to create nightingale (scrub) habitat on their land.

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