Bearded Tits and Grit-The Season to Date

Its been a rather frustrating season to date compared with the previous nine years of our study of gritting behavior. This weekend was typical, 15 birds (all colour ringed) on the trays on Saturday,  so full of hope I canceled plans to ring and spent Sunday morning watching empty grit trays on what appeared to be a really suitable morning-calm and cold. Frustrating to say the least.

However a  quick look at the sightings to date produced some interesting findings. In total to date we have recorded 176 sightings of colour ringed birds. This compares with 290 for the same period last year. But there are more young birds this year (45 compared with 17 in 2012). However we have recorded 25 different adults and 28 birds of the year visiting the trays this year, compared with 29 adults and 11 young birds in 2012. Effort have been very similar,  so we have recorded more individual birds this year but they are obviously visiting the trays less often. In 2012 one bird visited on 22 days. This year  the largest numbers of days by an individual  was just 10. I suggested in a recent posting that the mild weather and low water levels may be the reason for the  lower use of the trays

Overall though survival this year to date has been good. We ringed  21 nestlings and 16 of these survived to at least 2 months. Of the 45 juveniles ringed, 38  at least survived to early August and 32 of these have been recorded post moult.

Survival over last winter has also been good for  of the 17 birds ringed as juveniles in 2012 no fewer that 13 have been recorded  this year, a crude survival rate of 78%.

John

Recent Recoveries

The latest batch of recoveries included some interesting movements-
A Willow Warbler ringed near Carlisle at 08.45 on  on 6th of August was caught at Leighton 80 km south 25 hours later while a Chiffchaff ringed at Heysham on 28th September was caught at Orfordness in Suffolk eight days later, a distance of 370 kms.

A little more usual were two Sedge Warblers in France bringing our total of Sedge Warblers reported on migration through France to 43. A juvenile had traveled 705 kms in 13 days.

This late summer/autumn has been exceptional for the numbers of Mediterranean Gulls frequenting especially the Heysham power Station Outfalls. The rings or colour rings were noted on four birds. Three had been ringed as nestlings in The Netherlands and one in Germany. These now bring the totals of birds reported in our area to The Netherlands 6, Belgium 4, France 2, Germany 1  and Poland  4. All except two of he Polish birds were ringed as nestling's.  Many of them have returned in successive years with others moving to other wintering areas.

Our ringing of both Siskin and Lesser Redpoll has increased recently with Mark and Dave contributing good numbers in Bowland. A Lesser Redpoll ringed there on May 5th was caught in Glen  Clova in Aungus on 8th of October a movement of 342 km North. We have ringed similar numbers of these two species over the years but this is only our 4th Lesser Redpoll in Scotland. By contrast we now have 35 Siskin from Scotland including one in this batch in Lanarkshire.

A Goldfinch ringed here on 15 of October was caught, presumably in its wintering area at Ascot 330 km SSE on the 3rd of March. We have several other similar recoveries.

John

First Twite Captures Under Our Own Colour Scheme

Over the last few days the first arrivals of passage/wintering Twite have been present at Heysham Harbour.  This morning finally saw weather that was suitable for a catching attempt.

 

Three whoosh net operations resulted in the capture of 21 Linnet (including 4 retraps), 14 Goldfinch (including 5 retraps and one colour ringed control from Walney Island, which I understand was ringed there on 29/09/2013)  and 9 Twite comprising 5 new birds, 2 retraps and 2 controls.

 

The Twite controls consisted of another individual ringed at Machrihanish Bird Observatory in autumn 2012 and a returning bird ringed on Sanda Island (04/07/2012).

 

The 5 new birds were the first to be ringed under our own colour scheme that identifies each individual.  An example of the arrangement is illustrated here:

Posted after lengthy difficulties in getting access to the blog again!!   ajd

Bearded Tits October Grit Tray Sightings

This October has turned out to be one of the  most intriguing and at times most frustrating of our nine year study of the gritting behavior of this charismatic species. Despite a good population with 45 young birds ringed this year and at least 26 colour ringed adults identified, sightings on the trays have been the lowest since our study started. The average number of October sightings in past years has been 245, this year we have recorded only 107 despite much effort.

Why the difference? Well  this has been the warmest October since the study started with no frost and an abundance of insects- the main food of Bearded Tits in summer.  So possibly they have not had to turn to what is normally their main food at this time of year- reed seed. this is much harder to digest than insects and they need grit in their gizzard  to grind it up. Interestingly the only days numbers have been present has been on the cooler calm days. One of these fortunately coincided with the filming by the BBC Autumn Watch team when 15 birds were present.

The other difference this year is that the water level is much lower and large areas of dry  substrate, normally under water are accessible to the birds and they could possibly be getting grit there although there appears to be very little grit in the deep peaty soil.

Despite the lower numbers  there were several interesting sightings both of adults which have retained their pair bonds, in one case over three years, and of first year birds which have established pairs  shortly after fledging and are still together.

John