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SOS Marsh Tit survey 2020

SOS Marsh Tit survey 2020


Both Marsh Tit and Willow Tit, the two Poecile species in Sussex, have declined nationally. The later species is the second fastest declining species in the UK, after Turtle Dove, having declined by 93% since the 1960s. A Sussex survey for Willow Tit in 2019 failed to find a single bird and the species is, in all probability, now extinct in Sussex.

Marsh Tit declines have been slightly less severe but, nevertheless, numbers have fallen by 80% since the 1960s and the species was added to the red list in 2002. Anecdotal evidence suggests that the species might be doing better in Sussex than some other areas but we need better data if we are to properly understand its status and trends.

We are, therefore, asking for help to conduct a Marsh Tit survey this year to obtain statistically robust evidence. A maximum of two visits is required per 1km survey square between mid-February and mid-April.


The objective is to establish a base line population estimate for Sussex so that we establish the current status of the species. This survey will become part of our repeating cycle of SOS species surveys so we will be able to track the population trend in the county over time. This will give us warning if the species continues to decline.

Survey methods

We have selected at random a sample of 1km squares in the Sussex range of Marsh Tits. We excluded the coastal belt and the eastern end of the South Downs as the species was missing from these areas at the time of the last Atlas. We have selected 60 1km squares and are hoping that we can get a minimum of 30 of these surveyed (the more the better). This should be a large enough sample to provide a reliable estimate of the probability that any given square is occupied and, hopefully, an estimate of the county population.

If the interest and demand is great enough we have further random 1km squares which we can allocate in due course.

Marsh Tits set up territories early in the season and are easiest to detect using a playback methodology. We will provide a standard (2 minute) song file that can be played on a smart phone or other playback device (although it is possible to do the survey without using playback).

You will be provided with 1:25,000 maps of your 1km square and asked to make up to two survey visits between 14th February and 15th April to play the call near suitable woodland and scrub habitat. There will inevitably be areas of the square where access is not possible or where the habitat is clearly unsuitable and we will ask you to mark these on your survey map with cross hatching.

In addition to the survey of random 1km squares we will encourage observers to make a special effort this year to submit any Marsh Tit records from elsewhere in the county.

How to take part?

If you are interested in taking part in this survey please contact the SOS Surveys Officer (email below). Please have a look at the list of randomly selected 1km squares and indicate which one(s) you can cover. We will organise the maps and recording forms to be sent to you well before the 2020 season. Please indicate if you are happy to receive the information via email or if you would prefer a hard copy.

Thank you for your help

Richard Black (SOS Surveys Officer)

Telephone: 07736 460955

The 1km squares we are hoping to cover for which volunteers are still needed are as follows (updated 31/1/20):

TQ0429           Near Roundstreet Common

TQ0523           North Wood near Adversane

TQ0930           Near Slinfold

TQ4112           Hamsey