House Martin Survey 2015


The primary aim of the 2015 UK House Martin Survey will be to produce an estimate of the current UK House Martin population size, using a method that is repeatable to enable us to measure future population changes. A secondary aim will be to collect further information about nest site selection so that we can undertake some analyses to investigate whether any regional differences exist.

It is anticipated that the survey will be complemented by an additional survey in 2016, which will involve the collection of more detailed information about nest characteristics and timing of nesting activity (‘nest study’). This is expected to be an online survey with volunteers selecting their own sites.

The 2015 Survey

The 2015 survey requires three visits to be carried out, a ‘recce visit’ in mid to late May, followed by two survey visits in June/July. These are timed to coincide with the peak breeding period when most first broods are being fed and before they have fledged. Our pilot work showed that once first broods had fledged, it became more difficult to work out how many nests were apparently occupied.

Key survey dates 2015

March-May Square request system available to potential volunteers, online allocation of survey squares to volunteers

Mid to late May ‘Recce’ visit

June 1st to 24th First survey visit

June 25th to July 19th Second survey visit

October 31st Deadline for online and return of paper forms to The Nunnery

The UK House Martin Survey is an online survey and we hope that the vast majority of volunteers will be able to print out their own forms and input the survey results online. However, we do not wish to exclude potential volunteers who do not have online access so please contact me (details below) so that I can organise paper forms and to allocate squares online via the national organiser.

Survey Design

The survey design involves the selection of random 1-km squares, using a stratified sample in order to produce robust population estimates. The stratification is based on land cover data, which has been analysed using Bird Atlas 2007–11 counts, to categorise the squares into high, medium and low habitat quality for breeding House Martins.

All 1-km squares without suitable habitat have been excluded (i.e. no farm buildings at all). However, there are a number of 1-km squares with only a few buildings in them so it is hoped that fieldworkers will take on additional squares.

A recce visit will be most useful in squares where access issues are likely, where there are a large number of buildings, or where there are known colonies. If there are only a small number of buildings and the visits are likely to be short, a recce visit may not be necessary prior to the first survey visit.

If no House Martins are found, either during the recce visit or the first survey visit, and there are no signs that House Martins have recently used the square, a second main survey visit is not necessary. The following conditions need to be met for this to apply:

  A visit took place on or after 1st June.

  The volunteer is confident that she/he thoroughly covered all potential House Martin nesting habitat within the square.

  No House Martins were seen or heard during either the recce or the first visit.

  No signs of former nesting were seen in the square (i.e. old nests or nest deterrents).

A second survey visit is desirable if the square contains a large number of buildings, even if it appears unlikely that any House Martins are present. In this situation, it will more be difficult to be certain that no House Martins have been missed during the first visit and therefore a second visit will help ensure that our results are robust.

Recording Sheets and instructions for volunteers

  Map of the survey square (one copy of the map is required for all three visits)

  Visit Summary form (one copy is needed for the two main survey visits)

  Colony Information form (one or more copies will be required for the two main survey visits, depending on the number of colonies found in the square)

  A copy of the summary instructions and codes

Copies of these forms will be available to print from the House Martin pages on the BTO website. The survey map is specific to the selected 1-km square and will only be available when the volunteer has been allocated a square and has logged in to his/her House Martin survey home page.

Volunteers will also be able to view online, and print, the following additional resources:

  Full instructions

  Full list of survey codes

  Health & Safety for Volunteer fieldworkers

  Additional guidance about surveying in residential areas

  A letter of introduction confirming your participation in the survey

  An information leaflet to hand out to members of the public Health and Safety guidelines for BTO volunteers (

In Suffolk, we have approximately 100 1-km squares to survey. We require your help to make this survey a success so please make contact with me or request a 1-km square online.

From around mid-February, I will be able to allocate survey squares to volunteers using the BTO Survey Management Portal. Potential volunteers will be able to view the map of available squares on the BTO website and submit a request to cover an available square. This request will generate an email to myself, the Regional Organiser.

Mick Wright

RR for Suffolk

Tel: 01473 721486