A brief analysis of Grasshopper Warblers ringed at Lytchett Bay 2004 - 2013

Ringing has occurred every summer in the reed beds around the north-west shore of Lytchett Bay since 2004.

Grasshopper Warbler is an uncommon migrant and rare summer visitor to Dorset. However its perceived occurrence on autumn migration is strongly influenced by a combination of its habitat choice and unobtrusive behaviour. It is generally silent and remains hidden in dense vegetation or long grass.

126 Grasshopper Warblers were ringed between 20^th July and 2^nd October during the ten year period. In the same period there have only been 5 field sightings.

The annual distribution is shown in Fig 1

 Over the period the ringing method has remained largely unchanged, though the number and location of nets have varied to a small degree. The song of Grasshopper Warbler is played via a cassette and speakers, on a mixed tape with Aquatic Warbler song, from 45 minutes before dawn until 08:00.

Ringing was undertaken on 134 dates between 20^th July and 31^st August over 10 years, the peak migration period for Grasshopper Warblers. At least one bird this species was ringed on 54 dates (40.3%). In addition ringing occurred on 33 occasions in September. At least one bird was ringed on 7 dates (21.2%). 1 Grasshopper Warbler was caught in Oct, on the 2^nd in 2010.

The pattern of occurrence between the 20^th July and 4^th October is shown in Fig 2

Only one of the Grasshopper Warblers ringed at Lytchett Bay has been recovered. A first year bird ringed on 29^th Aug 2007 was taken by a cat 47 days later in Staplehurst, Kent on 15^th October. A surprisingly late date for a bird of this species to be in Britain.

Typical of migrant passerines ringed in autumn, the majority of birds trapped were first years. Only 7 (5.5%) were adults.

Birds move on from the area quickly. Only 2 birds have been recaptured on a subsequent date following ringing.

Shaun Robson

October 2013

A week of autumnal change

Four ringing sessions took place this week at Durlston NNR with a distinct change noted, not only in the weather but in the switch to late autumn birds.
The week began with fairly mild conditions and the recent trend continued of  ringing totals of around 100 birds -  mainly made up of Chiffchaff and Blackcap with the former making up the majority.
Then a session on Thursday saw a drop in numbers with only 23 new birds ringed.
Fast forward to Sunday and a weekend of unsettled weather, fall in temperature and the skies saw a increase in finches and thrushes.
This mornings total bumped up to 54 with the finch arrival noteworthy including 4 species of finch with Lesser Redpoll and Linnet both new for the year.

A warm and glowing sunrise greeted us on Wednesday morning

A lesser Redpoll is new for the year and attractive bird that we are always pleased to see

Several flocks of Goldfinches passed over this morning with 25 lured down 25 ringed

 

 Over at Lytchett bay Sean undertook a quiet ringing session with 8 new birds ringed with Cetti's Warbler being the highlight.

Posted By Simon Breeze

Larking around at the Dortset Bird Fair ringing demo

The weekend started with a ringing demonstration which attracted over 30 people all curious to come and look at how migrant birds are ringed, aged, weighed and measured and safely released to continue their journey on to their winter residence. Whenever we hold a ringing demonstration we always remind visitors that the welfare of the birds is of paramount importance and without the data gathered from this scientific and enjoyable pastime we would literally reduce our detailed knowledge of birds and their movements and behaviour by a considerable amount.



The usual flow of October migrants continued throughout the morning with Chiff and Blackcap being the most common. 145 and 31 respectively.

Highlight of the morning came just before the group packed away with 2 Woodlark.