NLRG was formed in 1957 to help in the study of birds in the Lancaster and District Birdwatching Society area. There are currently 12 active ringers. Species currently being studied include: Pied Flycatcher, Bearded Tit, Sand Martin, Twite, Goosander, Oystercatcher and Grey Wagtail. Migration has been studied for 28 years at Heysham. We welcome anyone who wants to observe, help or perhaps wish to become a ringer. Photo: A Heysham-ringed Twite on the Mull of Kintyre (thanks to Eddie Maguire)

Wednesday, 30 November 2016

Bearded Tit Gritting Season Draws to A Close

The last few days have seen very little activity on the gritting trays at Leighton Moss RSPB Reserve. From September 23rd to November 27th we have recorded a total of 307 sightings of colour ringed birds involving 64 different individuals. Of these 36 were adult birds and 28 this years young.
We don't record every day but we have some interesting statistics on the number of visits birds make to the trays.Sixteen have been recorded on only one day. At the other end of the scale the most recorded bird was a juvenile female which visited on 15 days visiting first on September 30 and last on November 27th.
At each visit the birds sort through the grit which is mainly builders sharp sand. They can stop on the trays for up to 10-15 minutes and they appear to swallow regularly. This is in line with some research in Germany where they found an average of 609 small stones and a maximum of 850 stones in the gizzard in early winter when they are feeding mainly on reed seeds, but only 38 in spring when they turn to invertebrates.
One question I am often asked- Does this consumption of grit increase the birds weight. I looked at the weights of birds we have caught and weighed this year. In July the average weight of 22 birds was 14.1 gms. in October the average weigh of 40 birds was 15.2 and of 22 birds in November it was 15.7. So they have certainly increased their weight by around a gram and a half.Would need a much larger sample and a statistical test to prove the increase. But its interesting and does at first sight suggest that taking grit may well play a part in the increase.We have checked birds for any fat and there is very little.
John

Sunday, 13 November 2016

Bearded Tits Still Gritting

Gritting continues especially on cold mornings. On Monday I recorded 14 different birds including 10 at once spread across the three grit trays at Leighton Moss RSPB Reserve. Difficult with so many birds present to work out pairings, all your attention goes into recording the colour ring combinations. They performed for ca ten minutes for an audience of 12 delighted birders, some who had never seen bearded Tits before. To date we have recorded 298 sightings of colour ringed birds involving 61 different birds. Of these 34 were adults and 27 birds hatched this year.Of the 61 35 were males and 26 females.

Yesterday though there were just four birds present, two apparent pairs. They gritted as pairs on separate trays. If any of the other pair attempted to join the other pair they were chased off.On checking their records I found they further proved what we have recorded on many occasions that Bearded Tits form pairs in their first autumn and if they survive they stay together through the year.

The first pair were hatched in spring 2015. They were first recorded together on 26th September and were recorded together on 5 occasions on the grit trays in October and November that year. This year they have been recorded together, either retrapped or sighted on the grit trays on 11 occasions.

The other pair were recorded together on seven occasions from late September to November in 2015.They we caught together on June 6th this year and have been recorded together on five occasions this October/November.

Very few other species form pairs early in life or remain together in successive winters.
John








Wednesday, 2 November 2016

Bearded Tit Gritting Season Continues

Since late September through to today we have recorded 255 colour ringed sightings of Bearded Tits almost all of them on grit trays along the Causeway at Leighton Moss RSPB Reserve. These have involved 59 different birds. Of these 33 were adults and 26 birds of the year. Of the 59, 33 were males and 26 females.

In our long term study of this species we have this year through retraps and sightings recorded 23 adult males and 18 adult females and 30 young birds making a total of 71 birds, so the 58 recorded gritting so far this season represents quite a large proportion of the known total population. These figures and those of the grit trays suggest that there are more males than females in the population. The catching of only 30 young suggests that productivity this year has been low and to date no unringed birds have been seen on the trays.

Past studies has shown that most birds visit the trays on under five days, but others make more visits with a record of 24 days by a first year female. Some birds visit early in the season then visit later presumably to top up the grit in their gizzards which they need this time of year as they change their diet from insects to the much harder reed seed. A German study found that in winter the average number of small stones in the gizzard was 609 with a maximum of 850, by contrast in spring they only averaged 38.

Gritting takes place usually between 08.00 and 12.00 and continues into mid December.

Sorry I have lots of photographs of the gritting behavior but for some reason the blog will not accept them.
John

Thursday, 20 October 2016

A Record Day

Yesterday was something of a record day. We caught 4 Cetti's Warblers in one net line. We have only caught singles before of this recent colonist. Up to 5 or 6 birds have been singing at Leighton Moss RSPB Reserve. One assumes that our catch originates from these breeding birds. However last October we controlled a bird which had been ringed just 38 days previously at Wood Walton Fen in Cambridgeshire a movement of 299 km in 38 days. So you never know.

We also caught our third Yellow-browed Warbler of the autumn and 8 Siskin the best catch so far this autumn.

But the most unusual catch was of a pair of Bearded Tits with consecutive ring numbers. I was amazed to find that they had been ringed as nestlings in the same nest in April 2014. We have ringed 673 nestling Bearded Tits as part of our long term study of this species. Many have been retrapped as adults but this is the first time we have recorded siblings as an apparent pair. Our observations do suggest that Bearded Tits do form lasting pairs. Interestingly neither of these birds have been recorded on the grit trays over the past two years.
John

Saturday, 15 October 2016

Bearded Tit Gritting Season in Full Swing


To date we have recorded 50 different colour ringed Bearded Tits using the grit trays at Leighton Moss RSPB Reserve. Of these, 27 are adult birds and 25 of this years young. No un-ringed birds have been recorded to date.

The first birds have been arriving on most days around 08.00 and the last leaving around 11.30. Wednesday the 12th was the best day this week when due to dedicated coverage by Alan, Pauline and Judith Gallagher no fewer than 28 birds visited the tray to stock up on grit as they change their diet from soft insects to the much harder reed seed.

To date in our ringing study this year we have identified 21 adult males and 17 adult females. Of these 38, at least 27 have visited the grit trays. Productivity appears to have been rather low as to date we have only caught and colour ringed 27 young birds of which an amazing 25 have visited the grit trays. We have this year been restricted to just three sites due to difficulty of access so we may have missed some but you wold expect unringed birds to start appearing.
John

Monday, 3 October 2016

A Bearded Tit Weekend


A great weekend for the 24th year of our Bearded Tit study at Leighton Moss RSPB Reserve. With excellent ringing weather on Sunday and much activity on the grit trays. In total we recorded 43 birds. This included 21 mist netted including six not ringed before and 22 on the grit trays. All the grit tray sightings were of colour ringed birds, not an unringed bird in sight! So far for our RAS study we have caught or sighted 30 adults- 16 males and 14 females. Two were first ringed as juveniles in 2013, 13 in 2014 and 15 in 2015. We usually pick up more adults over the next 10 weeks or so of the gritting season. I estimate that the breeding population this year is ca. 25 pairs.

Most of the birds visiting the grit trays at the start of the season are adults. This was true of a party of five today.A male and a female gritted together and were obviously a pair. They gritted together in early October 2015. If they both survive Bearded Tits seem to pair as juveniles and remain together for life. We keep detailed records of all sightings. Many birds are recorded gritting on only one day but some occur on up to 17 days. Often birds grit early in the season then have a break and return later.

John


Wednesday, 28 September 2016

Nuthatch Project Latest Report


The Group started colour ringing Nuthatch in spring 2015 with the view to starting an RAS (Retrapping Adults for Survival) on this species.Our activities have been centered round the well wooded Silverdale area where we have two feeding stations and seven nest box schemes. In total we have colour ringed 75 birds of which 44 have been nestlings.

Most of the adults have been ringed in Jerry and Barbara's woodland edge garden. They have meticulously recorded almost daily sightings. Between mid August and early April we colour ringed 22 adults there.Of the 16 ringed in August and September 2015 no fewer than 11 were still visiting the feeders a year later. This gives a yearly survival of 69.8%. We have had five ringing sessions in their garden since late summer and have only retrapped two giving a survival rate of only 12.5%. Certainly shows the value of colour ringing and close observation and recording and plenty of bird food!.

We did however catch and colour ring seven new birds on our five ringing sessions. Obviously young birds moving in. Two of them were from the same brood and had been ringed in a nest box two km. away. A bird ringed for the first time in late February and not seen again was sighted at feeders 3 km away from July on.
John
<