Farmland Bird Monitoring 2

2016 ringing photos

I completed my last ringing session of the winter in April. Despite the excessively wet and windy conditions over the winter period, I managed six mist-netting sessions at Woeful Lake Farm and a further session at Stones Farm. The site at Woeful Lake Farm consists of arable fields with a large area of cover crop and mature hedgerows. The site at Stones Farm is an old quarry surrounded by arable fields with grassy field margins and mature hedgerows. The quarry has a sheltered grassy area surrounded by scrubby bushes and trees. Both sites have been fed with seed throughout the winter. The site at Stones Farm has very good numbers of Yellowhammer, Linnet and Reed Bunting and looks to be a promising addition to the project next winter.

The table below summarises the birds caught for the first time and those recaptured throughout the winter period.

Species New birds Recaptures
Wren 1
Great Spotted Woodpecker 1
Dunnock 15 3
Robin 5 2
Blackbird 3
Goldcrest 3
Long-tailed Tit 2
Coal Tit 1
Blue Tit 48 21
Great Tit 14 1
Chaffinch 17
Greenfinch 12 1
Goldfinch 2
Linnet 13
Yellowhammer 8
Reed Bunting 1

The numbers of Linnet and Yellowhammer caught increased towards the end of the winter. This is because natural food supplies diminish as winter progresses and birds gather at areas where food remains – in this case where we provided supplementary seed. The relatively warm winter this year may have reduced the size of winter flocks – although there was a flock of up to 80 Linnet using the site this year, this is considerably smaller than the flock of several hundred present in previous years.

Examination in the hand revealed that the Yellowhammers and Linnets caught were a relatively even mixture of adult birds and first year birds (i.e. birds born in the 2015 breeding season). Previous studies and ringing recoveries have shown Yellowhammers in particular to be sedentary, with similar breeding and winter distributions and few long distances movements of birds. The capture of first year birds therefore indicates that Yellowhammers have bred successfully in the area last year and in the future it should be possible to look at changes in the proportion of adults to first year birds as an indicator of changes in breeding success.

To date I have only had one recovery of a ringed bird by a third party. A Great Tit ringed in December was recaptured by another bird ringer in Sibford Ferris (Oxfordshire) on 31 March 2016, a movement of 31km. It is unusual for a Great Tit to move as far as this but first year birds, such as this one, are known to be more likely to disperse than adults.

A more detailed report of the project so far can be found in the NCOS newsletter, and please continue to look out for colour ringed Corn Bunting (yellow with black characters) and Yellowhammer (dark blue with white characters) on the Sherborne Park Estate.

Farmland Bird Monitoring

Last autumn, NCOS kindly provided me with a grant to help set up a farmland bird ringing project on the National Trust’s Sherborne Park Estate. The Estate has good numbers of farmland birds present in both the breeding season and over-winter, including red-listed species such as Corn Bunting Emberiza calandra, Yellowhammer Emberiza citronella, Linnet Carduelis cannabina and Skylark Alauda arvensis. The project’s aim is to increase understanding of population changes and local movements of farmland bird species over the medium term to help us make conservation management plans for the Estate. I hope to achieve this by a combination of regular winter ringing sessions and nest monitoring in the breeding season.

Yellowhammer

Ringing birds is very weather dependant as mist nets cannot be used in windy or wet conditions and so there have been limited opportunities to get out so far this winter. However, I have fed the site since October and managed a number of short sessions, which have proved useful to observe bird behaviour and optimise catching methods. A flock of up to 100 Linnet has been building, and good numbers of Chaffinch Fringilla coelebs with smaller numbers of Greenfinch Chloris chloris, Goldfinch Carduelis carduelisi, Reed Bunting Emberiza schoeniclus and Yellowhammer have also been present, and I have so far ringed a number of these species as well as commoner generalist species. As winter progresses and natural food supplies diminish, I hope numbers will build further.

To maximise the data obtained by the project I will be colour-ringing any Corn Bunting and Yellowhammer caught, as both species perch prominently in the breeding season and so should be easy to re-sight. If any NCOS members are out walking on the Sherborne Park Estate, please check these species for colour rings and report them to CotswoldsCR@outlook.com. Corn Bunting colour rings are placed on the left leg and are yellow with one letter and two numbers engraved in black. Yellowhammer colour rings are also placed on the left leg and are dark blue with two letters engraved in white.

Barn Owls – Part 2

Barn Owls at six-and-a-half weeks

Barn Owls at six-and-a-half weeks

On last month’s expedition to ring a brood of Barn Owls we found another barn containing a nest-box that no-one had been aware of. Closer inspection revealed three newly-hatched chicks. As they were reckoned to be about one, three and five days old, they were too young to be ringed that day.

We came back nearly six weeks later and found an adult (which immediately slipped away) and two well-grown chicks. Don’t ask what had happened to the third…

A. ringing the elder one.

A. ringing the elder one

D. did the retrieving

D. retrieving the chicks in cotton bags

Weights...

Weights…

...and measures

…and measures

 

 

These chicks were slightly less advanced than the other brood when we ringed them – see how much down they still have compared to these.

M. who was supervising (Barn Owl ringing needs a Schedule 1 endorsement to the ringing permit) looked up the wing measurements in the tables, and pronounced the birds to be between 44 and 46 days old. This agrees very well the estimate of one to five days old when we first found the brood. It also suggests, unsurprisingly, that it was the youngest sibling that did not survive.

Barn Owls

Young Barn Owls Tom Beasley Suffolk

Young Barn Owls                                                         Tom Beasley Suffolk

After 2014’s massive year for Barn Owl breeding, 2015 has been miserable. M reckons he has inspected 40 boxes in the whole county this year and ringed one single chick!

A retrieving the chicks

A retrieving the chicks

 

Better news, though. A box near Sherborne contained a very young chick and three eggs at the beginning of July.

Several weeks later there were three well-grown young, just past the ‘ugly’ stage and shedding their juvenile down whenever they moved.

Measuring to estimate the age

Measuring to estimate the age

 

 

 

 

All three were ringed and measured. Incredibly (to me at least) you can age the chicks pretty accurately by measuring the seventh primary feather’s length and looking it up in guru Colin Shawyer‘s tables.

M weighing a chick in the bag

M weighing a chick in the bag

 

 

 

Weighing was also a surprise – the older the chick, the lighter they are.
They reach their maximum weight in the nest and slim down to flying
weight as they develop.

New Groups

Barn Owl       -  rob Brookes, from 'Birds of the Cotswolds' (Liverpool University Press 2009)

Barn Owl – Rob Brookes, from ‘Birds of the Cotswolds’ (Liverpool University Press 2009)

Two new bird study groups have been set up within the county recently. The first is the Gloucestershire Barn Owl Monitoring Programme, which seeks to provide advice and support for Barn Owl conservation. This project will liaise primarily with landowners and farmers, as Barn Owls have become so dependent on nest-boxes and the land on which they are sited. Sightings are crucial, though – if you don’t know where the owls are, you can’t put up nest-boxes or ring the birds.

The other group is the Gloucestershire Raptor Monitoring Group. This group will study a mixture of raptor species (suggestions welcome) and may also include Ravens, whose lifestyle and survey methods have similarities with raptors, and other owls. These species are far less popular with landowners – for understandable reasons – and the emphasis will be on birders logging sightings, breeding activity and behaviour.

The Gloucestershire Raptor Monitoring Group held its first meeting last Saturday at St Peter’s High School, Gloucester (a big thank-you for providing the facilities for free!). There were over 50 people there of all levels of skill and experience, but united in enthusiasm. The species picked out for further study at the moment are: Peregrine, helped by a very entertaining account of those at Symonds Yat by Steve Watson; Kestrel, whose numbers here have perked up this summer (but for how long?); Red Kite, which have now bred in the county for the first time in 150 years; and Goshawk, a fair number of which have been ringed due to Rob Husbands’ climbing ability and Schedule 1 licence.

Pics:   Mervyn Greening

Pics: Mervyn Greening

Picture:  Mervyn Greening

Nest Recording

An excellent talk from Ed Drewitt on Urban Peregrines last night at our AGM. Also a chance to meet various Forest of Dean volunteers from the RSPB’s Peregrine site at Symond’s Yat – thanks for making the long trip, and all crammed into a single car!

095_PE_P_1597

You looking at my nest? You’ll need a Schedule 1 licence                                          Photo: Dave Pearce

Our own (‘our own’…!) urban Peregrines in Cheltenham are progressing well this year with four eggs laid in early April. We will be watching closely for developments in the nest over the next few weeks, and putting video clips on this website.

Recording what happens in nests gives a whole new view of birds that you don’t get from simply spotting them. Date of laying, clutch size and nestling survival rates give an insight into a bird’s breeding biology, and also shed light on the environment around it.

It’s even better if you happen to have a huge database stretching back many years to compare with. The British Trust for Ornithology’s Nest Recording Scheme is 75 years old this year (NCOS has been contributing to it as a group for 10 years). As well as looking at how different species are doing at present, it means the team is able to look back and chart timelines. UK Peregrines, for instance, declined through the 1950s and 1960s: they laid the same number of eggs as before, but fewer hatched. This led to the examination of the nests and eggs, and the discovery of thinner eggshells, and then to the link with pesticides in eggshells. They recovered later (same number of eggs but more hatched) and started moving into urban areas around the millenium.

Anyone can record nests, whether in the countryside or in your back garden nestbox, and this is the time of year to get involved. Check out NRS News: this is the 2013 breeding season – why not contribute to the 2014 version?

The Breeding Bird Survey – guest post from Gordon Kirk, BTO regional representative for Gloucestershire

The Breeding Bird Survey (BBS), organised by the British Trust for Ornithology, is the most important survey for monitoring the fortunes of our more common breeding birds. All over the country, thousands of volunteers survey “their” 1km square every spring, recording all the birds they encounter. These randomly-selected squares are surveyed every year and this constant effort provides a huge and valuable set of data from which population trends can be calculated, providing important feedback on the state of the environment. Currently, about 70 people survey squares in Gloucestershire.

Why not join this happy band?…..if you enjoy doing a NCOS summer or winter survey, you will love BBS! You need to be reasonably confident that you can recognise common birds by sight, call and song. You survey your square twice – once in April / early May, and again in late May /June. Most observers also visit their square in March to walk the course and record some details about the habitat – is it woodland, farmland, urban etc? Each visit might take about one and a half hours. Almost all observers submit their sightings online, but you can fill in paper forms if you wish.

Currently there are fourteen available, unallocated squares in the NCOS area, listed below. Have a look on a map to locate them, and if you taking on one of them or finding out more, please contact me on Gordonkirk (at) aol.com. It may be necessary to seek permission from landowners in order to survey some squares (those marked with an asterix below are probably in that category, but don’t let this put you off – most landowners are happy to agree to this, and it is always great to survey otherwise inaccessible areas); I may be able to assist, and can certainly provide a BTO letter of introduction. There is a BBS training session on Sunday 6th April (9am -12noon) at Frampton on Severn, designed to introduce new observers to the survey (and each other!) – again, contact me if you would like to attend. It’s free but I need to know numbers.

Available squares:-

SO9026*  NW of Cheltenham
SO9108  N of Bisley
SO9809*  NW of Cirencester, just off the A417
SP0306  Baunton Downs
SP0403*  NE of Cirencester
SP0426*  SE of Winchcombe
SP0637  SE of Aston Somerville
SP0715*  W of Northleach
SP0935  N of Snowshill
SP1009  N of Ablington
SP1203*  NW of Fairford
SP1602  NE of Fairford
SP1736*  NE of Blockley
SP1930*  SW of Moreton-in-Marsh

 

 

 

Sherborne

 Sharborne Park   A Lewis

Congratulations to the pair of Mute Swans on Sherborne Water for hatching nine cygnets – quite a large brood – and then for seeing all nine through to near-adult size: this is much more unusual.

More worrying from Sherborne, though, is the complete lack of Willow Tit sightings. This is usually one of the few reliable sites in Gloucestershire outside the Forest of Dean for this red-listed species. None have been recorded here since before Christmas.

There have been a couple of recent Willow Tit surveys in the Forest of Dean. Ben Macdonald and Lewis Thomson attempted to identify territories and breeding success in 2010 and 2011, and Nick Christian and Rob Husbands have started a longer-term study including colour-ringing and the provision of nest-boxes.

An independent suggestion led to several NCOS members putting up some nest-boxes at Sherborne with permission from the landowners. The boxes are a short distance from the Willow Tits’ usual territories, and are packed either with wood-shavings or polyurethane foam: the birds insist on digging out a new chamber each breeding attempt.

Something's had a peck at this, despite the mud camouflage.

Something’s had a peck at this, despite the mud camouflage.

We aim to investigate whether the species will move the short distance and excavate the boxes, and general factors affecting the breeding of Willow Tits at this site.

 

The Siccaridge Six Hundred

Siccaridge Wood, Stroud – a Gloucestershire Wildlife Trust reserve
Emma Bradshaw

Gloucestershire Wildlife Trust are carrying out a ‘BioBlitz’ – a non-stop 30-hour survey of all wildlife – at their picturesque Siccaridge Wood reserve in the Stroud Valley. The aim is to find 600 species.

Drop in any time between 10:30 on Saturday 15th and 4:30pm Sunday 16th June and stay as long as you like. There are a number of different walks and events during the two days, with experts on hand (including the odd NCOS member!) to help identify the various taxa.

GWT has several reserves in the area, and of course there’s the Daneway Inn close by.

Surveys & Woodcocks: Welcome to Gordon Kirk, BTO Gloucester rep

Most of you will know that the British Trust for Ornithology (BTO) is the leading bird research organisation in the UK, combining the scientific expertise of a small group of professional staff with the enthusiasm of a large team of volunteer birders across the country – one of the best examples of ‘citizen science’ that you will find.  Gordon Kirk – one such volunteer birder and also an NCOS member – is the BTO’s new regional representative for Gloucestershire and is now the first point of contact for all BTO matters in the county.  As many NCOS members participate in BTO surveys and take an interest in the wider work of the BTO, Gordon will be contributing occasional posts to this blog.  He says that some will be blatant attempts to get people out in the field to look out for birds, while others will be less demanding.  As we are approaching the key spring/summer surveying period, his first post falls into the first category dealing with the Breeding Bird Survey (BBS) ( and details of training on 14 April) and this year’s survey of breeding Woodcock which gets underway next month.

For more information about getting involved with these surveys – or any other BTO matters – contact Gordon Kirk, the BTO’s Regional Representative for Gloucestershire via the contact us page on the website.

Over to Gordon …………………

Hi

BTO Surveys for the 2013 breeding season

Breeding Bird Survey (BBS)

The BBS is the cornerstone of the BTO’s long-standing work to monitor bird populations, and involves visiting a 1km square two or three times during the breeding season to record birds; you need to be reasonably confident that you can identify common birds by song as well as by sight. Several new volunteers have signed up for BBS this spring, so we have a record number of 1km squares allocated in the county. Therefore BTO will soon be releasing some more randomly-chosen squares, which will be available for surveying this spring and summer. So why not join the increasing band of BBS volunteers? Details of what is involved can be found on the BTO site.

A free BBS training event is being held from 9am – 12 noon on Sunday 14th April, at Frampton on Severn Village Hall, where there will be a walk to do a ‘dummy’ survey as well as further information and the opportunity to ask questions and meet fellow observers.

Breeding Woodcock survey

The recent atlas surveys raised concern about Britain’s breeding Woodcock population, suggesting that the range may have contracted – which if true will almost certainly also mean that numbers in the core areas have decreased. However, the methodology for the atlas fieldwork was not well suited for monitoring Woodcock, which is of course a crepuscular and nocturnal species. So a new national survey is taking place this year to monitor numbers and compare them with those found in the last survey in 2003. Nineteen squares in Gloucestershire have been identified by BTO for surveying, and most of these have already been allocated, in many cases to the same observers who surveyed them in 2003. But there are a few left, and also anyone can nominate an additional 1km square for surveying, so why not see if a woodland near you holds any ‘roding’ Woodcock? The survey involves three visits around dusk, and rather than walking around you simply choose a fixed point with good visibility and record any Woodcock activity, as well as making a note about the habitat and any deer activity that you see. Details on the BTO site