Sandwich Bay Bird Observatory Motus receiver – we have a positive detection!

Members will remember that at the start of this year we became part of the Motus project (explained below) with the help of a generous bequest from the estate of Vida Madell, who was a member of the Observatory and ringing team. We now have a confirmed detection as detailed below.

February saw the installation of the newest Motus UK receiver – an automated detection system for tagged birds and bats, which links the UK to mainland Europe by working on the same radio frequency. Sandwich Bay’s receiver has seen several detections of birds over the last few months, but unfortunately many of these have been identified as false, due to random radio noise possibly caused by ships or other background noise.

However, we have a positive!

A Whitethroat that was tagged in Germany on 28th August, close to the border with Denmark. It moved slowly in a southerly direction over the next few days, eventually arriving near to Freiberg on 31st August – it stayed there until Sept 1st, but then was not detected until 4th September until it ‘pinged’ the receiver at Sandwich Bay (see image below).

This means the Whitethroat travelled across northern Europe – a distance of 606 kilometres – in 3 days, 22 hours and 52 minutes, giving an average speed of around 6km/ hour. We know that it probably travelled across the channel – where it would not have been able to land – at a much faster speed, as the European Robin did when it travelled from the Hoek van Holland to Lowestoft at a speed of around 26km/hour (

The detection table here shows the order in which it ‘pinged’ various European receivers.

It is obviously very exciting to have a valid detection on the receiver at SBBOT – let’s hope we get many more and that we can expand the tracking network in the UK to match that of our colleagues on the continent.

2021 should also see the deployment of the first MOTUS tags in the UK, and there is always the chance that some of these will be picked up across the channel as well.

For more information about Motus including how the technology works, go to:

To look at the detections on the SBBOT receiver, go to:

There is also some information on the growth of the UK Motus project on the University of Hull’s Ornithology group website:

Friday 27th

Early rain and wind put paid to any hopes of a late ringing session. The session on Wednesday might prove to be one of the last this year depending on restrictions. It yielded 15 new birds including a Firecrest and a Moorhen. Goldfinch outnumbered Lesser Redpoll nine to two.

We are still getting a trickle of interesting recoveries  and more of those later.

Monday 23rd

The forecast calm morning arrived but it brought a thick frost with it. At this time of year it took the suna while to remove it. It was well worth putting up with cold extremeties as 71 birds were caught of which 56 were new. A tristis Chiffchaff was the highlight. Thirty six Lesser Redpolls made up the biggest group, unusually for this year, none of these already had rings. Two Common Redpolls accompanied them. There were five Great tit retraps all of which were males.

Trisitis Chiffchaff. 23/11/20. I Hunter



Sunday 22nd

With dispensation being granted under strict guidelines and the wind dropping it was interesting to find a few Redpoll still moving. Twenty birds were ringed- 11 Lesser Redpoll, four Blackbirds, three Redwing, a Fieldfare and a Robin. The slight surprise, given the mild conditions was that there was not a Chiffchaff or Goldcrest.

Monday 16th

A few more of the movements we have been notified of recently:

Once again evidence of young birds reaching the coast and then loitering. This time a Reed Warbler ringed here on July 17th and retrapped at South Foreland (15km south) on August 1st. Secondly, a Blackcap ringed at South Foreland on September 5th and retrapped here two days later.

Whether a Blue Tit ringed at Kingsdown and retrapped here six days later was a migrant (they do move through here) or local dispersal is difficult to say.

Tuesday 10th

With restrictions preventing most ringing a resident made an attempt near the feeders next to the Obs pond but a combination of the feeders having not been topped up regularly and the mild weather meant it was a quiet session. The three new birds were an eclectic mix of Grey Wagtail, Goldcrest and Goldfinch.

Friday 6th

There has been a good number of movements to report on of late and two of the latest batch are of particular interest as they are not leaving the country and both seem a bit unexpected.

The first is of a Chiffchaff. It was ringed here on October 9th 2020 and caught again at St Mary’s Reservoir, Surrey on October 20th. This is 131 km west of here i.e. inland.

The second is of a Blackbird. It was ringed here on October 19th 2020 and caught again at Gibraltar Point, 216 km NNW. We normally think of thrushes coming in from northern Europe and then spreading inland, this one seems to have coasted northwards.

Wednesday 4th

For the first and last time this month we were able to do a full session and very interesting it proved as well. The wind dropped and it was a beautiful, calm, start to the day. The sky was completely clear and a strong frost formed until it was burned off by the warm sun. As the team drive/cycle in from the surrounding area we will not be doing that until the end of lockdown.

One hundred and fourteen birds were caught of which 86 were new. Lesser Redpoll led the way with 44 plus a UK control and, most interestingly, a retrap of a bird ringed here on November 6th 2018. It has not been recorded here in-between and they do not breed here. There was also the fourth Common Redpoll of the autumn – we would normally hope to have a chance of catching one or two more at this later stage.

The next most common species was House Sparrow with ten birds plus a retrap. We have probably caught them out a bit because although the feeders are being topped up we have not been able to ring and so they have got used to unfettered access.

There was also a mixture of thrushes with five of Blackbird and Song Thrush, two Redwing and a Chiffchaff. Blackcaps continue to appear (three more) and hopefully one day we will find out if they are late departures or new arrivals.