June 2002 - Newsletter 83 Print

Update on Atlas Recording Along 2km Routes

Helen Parry Jones

Recently, you will have received a letter from the Chairman, Andrew Baker, about counting birds along a 2km route. You were asked to record every bird you see or hear along the route and within 100 metres either side of you, and to tot up the total numbers of each species seen or heard. You were also asked to state the start and end points of the route so that the records could be allocated to the correct tetrad for the Atlas.

I was speaking to a member who set out to do this, but abandoned it because they couldn’t distinguish between all the birds that they were hearing (e.g. Sedge Warbler/Reed Warbler), though they  were confident about the recognition of other species such as Common Whitethroat. My instinct was that if you counted the birds you recognised along your 2km route, the records would be valuable to indicate population densities of the selected species within an area. Atlas Co-ordinator Al Venables has confirmed this.

You therefore have a few options depending on your confidence and ability:

  1. Comprehensive. Confident with all that you are seeing and hearing and your ability to record all species, so absence of a record indicates absence of a species along that route.
  2. Selective List. Confident with a few species by sight and sound. Write down the list that you are familiar with and record within this list. For example, if you are familiar with Wren and Robin, these would be on your selective list. Therefore if you recorded Robin but not Wren on your 2km walk, this would indicate absence of Wren on this route.
  3. Specific Species. You may do a regular walk but be overwhelmed by the number of species to record. You may therefore decide to record Wren on one day, Common Whitethroat on another etc. Such records are also extremely useful.

Wherever you are recording, please remember to specify, the start and end points of your 2km route, so that the results can be allocated to the correct tetrad. When you send in your counts, it is  important to remember to indicate whether your recording was comprehensive, selective or specific.

Caerphilly Biodiversity Action Plan Launched

Richard Clarke

Caerphilly County Borough Council has launched its Biodiversity Action Plan. The Plan includes individual species plans for a whole range of flora and fauna found within the Council’s boundaries including plans for over 20 species of bird.

Some of the bird species included also have UK plans such as Song Thrush and Reed Bunting, but others were selected by local residents and represent what is of interest in the area for example, Barn Owl and Green Woodpecker.

Each plan sets out clear objectives and targets aimed at maintaining the species within Caerphilly. GOS has played an active part in preparing the Plan having provided distribution maps for the bird species and also writing some of the bird accounts. As a member of the partnership that prepared the Plan, the Society will continue to have a role to play mostly in monitoring species through various surveys.

The launch of the Plan saw all partnership organisations coming together at a “Go Wild” day. This included stands and stalls with many activities and events and was hosted by Caerphilly at the Council offices at Pontllanfraith. The Society played its part and ran a free quiz on bird identification with free Gwent atlases given to those with top scores. This proved very popular with some 60 entries being made during the event. As most of these were by family groups we estimate that there must have been at least 150 people involved in the quiz - including one Assembly Member!

Overall the event was very successful with lots of interest being shown by local residents. With so much time and effort already being committed into the project by so many partnership organisations it is already off to a very promising start and it is hoped that this will now feed through to the benefit of local flora and fauna.

A copy of the Caerphilly Biodiversity Action Plan will be placed in the GOS library for members to view.

Torfaen Local Biodiversity Action Plan Photographic Competition

Steve Williams

Torfaen County Borough Council is running a photo competition as part of their LBAP entitled ‘Wildlife on Your Doorstep’. This is a great opportunity for wildlife photographers to have their work published in the plan and to win a £100 in photo equipment vouchers. The only requirement is that entries must depict habitats and species found in Torfaen.

There are two categories; 16 and under, and 17 and over. The deadline for entries is August 7th. Further details including an entry form are available from Steve Williams.

Has Anyone Seen My Lapwings

Andrew Baker

I have helped survey Lapwings as part of the RSPB Lapwing recovery programme over the last few years. Trecrug farm at Llangybi, alongside the River Usk, has had 23 pairs of Lapwing nesting on it
for the last few years, making it the biggest colony in South Wales. However this year this has reduced to about 4 pairs. The most likely explanation for this reduction is that the birds have relocated to another area within a few miles radius. If anyone birdwatching or walking in this area observes an influx of Lapwing, please contact me as soon as possible.

Late update: I found 2 pairs 1 mile south of Llangybi at Newbridge-on-Usk on 25th May, but no mass populations yet.

A spot of good news is that 30 pairs of Lapwing are nesting on GLWR, up from 17 last year.

I have had 6 birds at Penyglog Farm, Llandegvedd Village BBS 1st May and 4 on 19th May, the first records at this site since 1996. These may be some of the missing birds. They are on fields recently ploughed and re-planted with maize. The fields should be undisturbed until the autumn, so if they can keep the Crows, Ravens and Lesser Black-backed Gulls at bay, they may be successful. I keep my fingers crossed! (Ed..HPJ)

The Welsh Lapwing Recovery Project

Published with permission from Tony Pickup, RSPB Lapwing Recovery Project Officer

Background

The Welsh Lapwing breeding population has suffered alarming declines in recent years. It was estimated that there were about 15,000 pairs in Wales until the early 1970s. In 1987 a national survey was organised by the BTO, and the estimated Welsh population was 7448. A repeat survey in 1998 revealed a 77% decline in the population to only 1700 pairs. The combined England & Wales decline for the period was 49%, with Wales having the steepest population drop of any region in the survey.

The dramatic fall in numbers is mostly ascribed to changes in agricultural practices, though other influences are probably at work as well. Annual agricultural returns provide a clear illustration of the changes in land-use over the time of Lapwings’ decline. Arable farming, important for providing nesting sites, declined from more than 15% of the improved land area in the first half of the 20th Century to less than 5% by 1992. Most of Wales’ farming is pastoral and, with increased availability of chemical fertilisers, stocking densities rose from 300 animals per 100 ha in the 1930s to over 800 by 1992. Although much of this increase has been caused by the increase in the Welsh sheep-flock, (3.98 million in 1945 to 11.12 million by 1992), the ground is also used more intensively, with stocking rates (in livestock units per hectare) doubling between the 1930s and the 1990s. All this has led to increased nest-losses from trampling, as well as a reduction in site availability through improvement of fields.

By 1996, following a number of years of mounting concern for the species, the RSPB had conceived a special recovery project. The long-term aim was to put Lapwings back into a sustainable, farmland avifauna. To fulfil this aim three objectives were set:

  • To arrest the decline on the major Lapwing sites in Wales by 2001.
  • To increase the Welsh population by 10% by 2004.
  • To begin the re-colonisation of the wider countryside by 2010.

Results

Breeding Lapwings in Gwent.

The records submitted to the Lapwing Recovery Project for Gwent are listed below. They contain 4 key sites (by the original definition) with 10 or more pairs: two on the Wentlooge/Peterstone levels and two in the Usk floodplain. Lapwing habitat use reflects the land use of the county with three key sites on wet grassland, and one on maize in floodplain grassland.

Grid Ref Site Name Key Area Pairs Observed per year
Lapwing Recovery Project Breeding data for Gwent
      1997 1998 1999 2000 2001
SO238097 Kays & Kears/Garn Lakes Bleanavon   4 4 4 0
ST235778 Rhymney Great Wharf Trowbridge     4    
ST237787 Newton Farm Trowbridge 11   6 4  
ST275818 Peterstone Wentlooge     12 10  
ST380972 Tregrug Farm S. Usk   20 20 25  
SO173123 Bryn Farm Common Brynmawr       2 6
SO345065 Pantybeilau N. Usk       10  

The National Project

By 31st March 2001, the project had encouraged positive Lapwing management on 36 sites, covering just over 1000 hectares. Twenty two of these are “key” sites, of which 16 had management paid for under the Lapwing Recovery Project. On managed sites, the Lapwing populations appear stable but, on sites where advice was either not given, or not taken up, the populations appear to have fallen by up to 20% per year.

Results suggest that the project is maintaining the number of breeding birds on “managed” sites but we are not sure whether we are actually achieving our conservation goal. Managed sites could be maintaining their numbers because we are enabling a population to provide sufficient young to replace its adult losses, - in which case we are succeeding in our aim. Alternatively, we could just be maintaining attractive nesting sites, which are pulling in birds from neighbouring sites to replace their adult mortality. In this case, we are doing no good and possibly doing harm. If we are to be able to retain Lapwing as a typical bird of farmland much more information is needed, as well as effort expended.

Finally, managing sites need not be part of a national scheme. If Lapwings are not only found on nature reserves, then localised efforts are going to be needed and they need not be large or formally organised. Simply helping a local farmer by marking nests to avoid their destruction could be doing significant conservation work for the species – but don’t forget about the chicks! There is a lot that can be done for Lapwings outside large and formal schemes. I hope that those of you who aren’t already involved in such work might feel tempted to do something.

The Lapwing recovery project finished December 2001, and support or payments to farmers to help safeguard Lapwing breeding will only resume if cash is forthcoming from the Welsh Assembly. This could lead to an accelerated decline such that there may only be Lapwings breeding on specially managed sites in Wales by 2010. A grim prospect.

Year Pairs on positively managed sites (n=25)     Pairs on non-managed sites (n=24)
Trends in Lapwing populations on sites subject to Lapwing Recovery Project advice.
1998 319 253
1999 320 212
2000 322 167

Nesting Barn Swallows

Ray Armstrong

Last year, true to form, a pair of swallows returned to nest in their ancestral home in our barn, which for the last 10 years has housed a single nest. This has been carefully refurbished every year and despite the generally poor spring/summer seasons, successive generations have managed to raise two broods successfully. The barn is of steel fabricated construction, open on one side, and the nest, rather difficult to see, is sited high in the apex of the roof, between two longitudinal beams. Considered by many to be the real herald of spring, the swallows arrived on 24th April and immediately advertised their arrival with the male delivering an extended rendition of his delightful twittering song from the television aerial on the house, their favourite perch. I call this their favourite perch since this is where successive pairs have regularly consummated relationship.

The serious nest refurbishment didn’t start in earnest until the second week in May but in the interim they kept us enthralled with their aerial skills as they flew around the house and barn. In the second week of May their efforts to refurbish the nest were stepped up, with mud being collected from the well paddled, muddy areas that surround the animal drinking troughs in adjacent fields, and from a small puddle on our drive. This construction work was conducted in regular bursts throughout the day. By the end of the week I knew the work was nearing completion when I saw them flying in with feathers to line the nest. On one such occasion as they approached the nest, the male dropped a feather he was carrying and the female immediately dived to recover it then dropped it again only for the male to recover it. This highly skilled apparently playful routine went on for 2-3 minutes, before they finally carried the feather to the nest. I construed this to be an instinctive celebration of a job well done, and considered myself extremely fortunate to have a ringside seat. All went relatively quiet for two-three weeks as the egg laying and incubation took place. I first became aware they were feeding young when I found an eggshell on the ground close to the nest, cut perfectly in half across its length, characterising a successfully hatched egg.

After about 10 days of non-stop feeding, we had a spell of extremely hot weather and I observed the young birds were hanging over the edge of the nest with their beaks wide open trying to keep cool. The fact that the nest was in the apex of the roof of the steel barn could only have exacerbated the heat problem. The resulting air temperature in and around the nest must have been in excess of 100oC over the mid-day period.

On going in to the barn after two further days of extreme heat, I found two fledglings on the ground beneath the nest. I suspected the excess heat had triggered the fall; they probably fell whilst jostling to take advantage of the increased airflow around the edge of the nest. Fearing they would become victims to our cat if left on the floor and concerned that my returning them to the nest might cause the other three fledglings to fall, I placed them on cross beam on the side of the barn about 3 metres above the ground. I then waited to see if the parents would find them.

The next time the hen bird came into the barn the chicks on the beam became very vociferous and animated, and after a couple of fly-pasts she flew in and fed them. Soon after she had left they became restless and started to shuffle along the beam on their weak legs and inevitably toppled onto the floor again. What next?

I remembered I had an unoccupied open-fronted nest box on the end of the barn. I nailed this to the beam, perched the two fledglings on the front edge of the box and stood back and waited. When the adults returned, they flew straight to the nest in the apex of the roof, leaving me thinking they were going to ignore the itinerants. However on the next visit, the male appeared to go to feed them, but then veered away and fed the young in the natural nest. This routine was repeated two or three times, by both adults, during successive feeding visits during which time the itinerants were getting hungrier and very agitated.

It occurred to me that the problem might be that the overhang on the nest box gave insufficient headroom for them to hover and feed, the natural routine as the youngsters get bigger. I quickly removed the nest box roof, and on their next visit the adults went straight to the box and fed the youngsters. All 5 young were successfully reared in their respective abodes, although I should add that the “itinerants” were the first to fly.

I am pleased to report that the swallows arrived this year on 16th April and within minutes of arrival they were twittering away in the barn close to last years nest, obviously discussing the “nest refurbishment programme”!

I will watch with interest.

News fromTrelleck

Ray Armstrong

A pair of Ravens has nested in a Scots Pine on Beacon Hill and is currently feeding young. Several small groups of 5-7 Redpoll were regularly seen on Beacon Hill and Broad Meend throughout March, with the last sighting on 8th April. A Willow Tit’s nest has been predated. This is particularly bad news as I suspect there are only 2-3 pairs locally. Three pairs of Lapwing have taken up territories in an arable field on the edge of the village. Migrant numbers appear to be down this year, though maybe there is still time for this to change. Arrival dates in the area are as follows:

Chiffchaff 19 March  
Tree Pipit pair 3 April  
Willow Warbler 4 April  
Blackcap 5 April 3 singing males Lower Lydart
Curlew 15 April  
Swallow 16 April  
House Martin 19 April  
Redstart 19 April  
Cuckoo 20 April  
Whitethroat 23 April  
Yellow Wagtail 25 April Llanrothal
Sand Martins 25 April < 50 excavating at Llanrothal
Garden Warbler 2 May  
Wood Warbler 6 May  

News from Chepstow/Newhouse

Andy Gabriel

Migrants
Whimbrel 1 Newhouse 28 April
  5 Newhouse 6 May
House Martin 2 Chepstow 21 April (returning to breeding area)
Reed Warbler 1 Newhouse 24 April
Sedge Warbler 1 Newhouse 24 April
Lesser Whitethroat 2 Newhouse 24 April
Whitethroat 3 Newhouse 26 April
Residents
Willow Tit 3 Chepstow 3 March
Marsh Tit 1 Chepstow 3 March
Cetti's Warbler 1 Newhouse 21 April

The Cetti’s Warbler is currently holding territory and is the first such record away from its more usual locations near Newport.

Dunlin Landing on Knot

Roger Price

Some members may know the stretch of Rhumney Great Wharf to the South of Peterstone Sluice Farm. In front of the area of the Great Wharf is a large rectangular area of soft mud retained by a wall of pit props. At high tide this is a favourite place for gulls and Grey Plover to perch.

A group of perhaps 20 Grey Plover were perched mainly on adjacent posts when small numbers of Dunlin and Knot, displaced by the rising tide, decided to join the group. However once the vacant posts within the group were occupied by Knot, further individual Knot ignored vacant posts at the end of the group and proceeded to alight on the backs of the Knot already perched.

This amusing spectacle lasted a few seconds before the lower Knot caused the usurper Knot to slip of its back by moving its wings. Some Dunlin also tried the same trick with the Knot putting up with this for perhaps five seconds before causing the Dunlin to overbalance. This was all done with seeming good humour and no aggressive reactions.

Bay of Biscay Trip

Helen Parry Jones

As of the 30 May, the only availability from Portsmouth to Bilbao between mid-August to 14th September is:

  • depart Portsmouth 20:00 Tuesday 27th August, arrive Bilbao 08:00 Thursday 29 August
  • depart Bilbao 12:30 Thursday 29 August, arrive Portsmouth 16:30 Friday 30 August

You can stretch your legs on land for a couple of hours at Bilbao.

13 people have already expressed interest and I have provisionally booked 6 x 4 berth inside cabins at a cost of £149.54 per person covering adult fare and berth. If more people join, the cost per person would come down a bit. If you want to come on this trip please let me know within one week of receipt of this issue of The Dipper.

Once payment is made, if you pull out I am afraid that you lose your money unless you can find a replacement. Please also be aware that the price above is based on 13 people between 6 x 4 berth cabins. Depending on final numbers, the price may be more or less than quoted. You will be told of any change in price. Finally, it will be up to you to sort out your own insurance.

Gwent Ringed Cormorant Big Hit with the Dutch

Richard Clarke

The Goldcliff Ringing Group’s Cormorant project got Dutch twitchers excited in March, when one of the Cormorants colour ringed in Gwent was spotted at Stellendam, Netherlands and caused a local twitch.

Gwent breeding Cormorants are, in common with most other UK birds, of the Phalacrocorax carbo race whereas local Dutch birds are of the Phalacrocorax sinensis race. Pure carbo birds are therefore something of a rarity in mainland W. Europe and the arrival of a bird from Gwent was met with some delight by Dutch birders.

In 2001, the Goldcliff Ringing Group (GRG) started to colour ring Cormorants. In all, 31 birds have been fitted with green Darvic rings with white lettering. The bird seen at Stellendam is one of a number of sightings to date of the colour ringed birds. The first were in August at Uskmouth and at Chew Valley Lake, Somerset. In September, a bird turned up Chard Reservoir also in Somerset and after the Dutch sighting we have had a bird seen at Otmoor, Oxfordshire.

With our colour-ringed birds now popping up all over the place it is perhaps surprising that there has been only one sighting of a bird in Gwent. Do you know of any others?

If you have any information about sightings of Cormorants in Gwent the GRG would be very interested to hear from you. We are especially interested in any information about our colour-ringed birds, but also details of loafing and roosting sites in the county. If you are able to provide any information please get in touch with me.

Recent Bird Hightlights

Compiled by Chris Hatch from information received on the G.O.S / Welsh Water Bird Line

January (omitted in the March Dipper). 20 Bewick Swans were reported from Llandegfedd reservoir on the 2nd whilst 3 Water Rails were at the same site on the rd. Five Short-eared Owls and a female Hen Harrier were reported from GLWR Uskmouth on the 3rd and stayed for the remainder of the month. Also present at GLWR Uskmouth was a Bittern which was first seen on the 3rd and stayed until at least the 15th. On the 5th, a Great Northern Diver was observed at Llandegfedd. Other interesting sightings during the month were: female Merlin at GLWR Goldcliff on the 14th, Long-tailed Duck at Llandegfedd on the 15th, Whooper Swan at GLWR Uskmouth on the 16th, Lesser Spotted Woodpecker at Gobion on the 20th, a Brambling near Pontypool, also on the 20th and a Kittiwake at Ynysyfro Reservoir on the 21st.

March: The male Ring -necked duck was present at GLWR all month whilst another bird of the same species appeared at Llandegfedd reservoir on the 17th. Two Red Grouse were reported from the Sugar Loaf on the 7th, whilst a Black-throated Diver was seen at Llandegfedd reservoir on the 9th. Merlins were present at Uskmouth (2 birds) on the 30th. Two Short-eared Owls were reported from GLWR on the 24th and were present until at least the 25th of April. A female Hen Harrier was also present at the same location on the 24th and was reported until the 23rd of April. Up to five Cetti's Warblers and up to 15 Little Egrets were also present on the reserve. Other sightings included two Water Rail at Llandegfedd on the 24th, and two Avocet at GLWR Goldcliff on the 30th. Earliest dates reported for migrants included: Blackcap from the 7th, Sand Martin from the 9th, Chiffchaff & Swallow from the 10th Wheatear from the 24th.

April: Birds of the month were a Hoopoe, present at Tredegar Park between the 4th and 6th and a Common Crane at GLWR on the 11th and 12th. Ring-necked ducks were reported from the Levels and Ynysyfro Reservoir. Two Merlin and two Avocet were at GLWR between the 1st and the 13th, Lesser Spotted Woodpecker and Brambling were reported from Llanhennock on the 16th, and a GLWR Goldcliff on the 14th and Firecrest was seen at Wentwood on the 22nd. Fourteen Whimbrel were at GLWR Goldcliff on the 23rd,, Arctic Tern and Fulmar were seen off Goldcliff on the 28th, and an Arctic Skua was at the same location on the 29th.

Earliest dates reported for migrants were: Willow Warbler from the 1st Redstart from the 14th Grasshopper Warbler from the 16th Common Sandpiper, Whitethroat & Yellow Wagtail from the 18th Cuckoo from the 19th Wood Warbler & Reed Warbler from the 20th Whinchat, Garden Warbler & Sedge Warbler from the 23rd Spotted Flycatcher from the 29th

May: An Osprey was present at Peterstone Gout from the 2nd, two male Garganey were present at Peterstone Gout from the 11th, a Wryneck was reported from Christchurch on the 13th, and remarkably, 8 Crag Martins were reported from Trefil on the 21st.

Cetti's Warbler in Gwent

Helen Parry Jones (from the archives)

Since about 1920, Cetti’s Warbler has successfully expanded its range over cooler oceanic lowlands fronting Bay of Biscay, English Channel and North Sea(1).

It was first proved to be breeding in Britain in 1972. There has been a marked spread since, mainly in south-east England and increasingly in the South West. It varies from migratory to sedentary in different parts of its range. The western race is mainly sedentary.

In Birds in Wales 1992-2000(2), Cetti’s Warbler is described as an unusual breeding resident in South Wales, probably increasing; occasionally recorded on passage. It has been regularly recorded in Carmarthen, Ceredigion, Gwent, Glamorgan, and Pembrokeshire, and had extended its range to Anglesey by 1997. Significant records in Wales and all in Gwent are shown in the table below.

To me, it is now unusual to go to the Gwent Levels Wetland Reserve (GLWR) at any time of the year without hearing at least one Cetti’s Warbler, although seeing one is another matter. Its explosive song alerts you to its presence, sometimes seeming to be within a couple of feet of you, but its skulking nature keeps it well hidden. With patience, though, you can get good views.

I take it for granted that I will hear Cetti’s Warbler at GLWR, but this species, first recorded in 1988, is still a relative newcomer to the County, and very restricted in its distribution. It has now been recorded annually since 1994, confined almost exclusively to a small area to the east of Newport, as shown by the sightings listed in the table below, though in 2001/2002 it may be “spreading its wings”.

Breeding has finally been confirmed in the county in 2001 at GLWR, Uskmouth.

Year Location (3) Number Date and Comments
1973 Bardsey, Caernarfon 1 First record for Wales (2)
1985 Oxwich, Glamorgan   First confirmed breeding in Wales, bred annually until 1992, then 1995, 1996 and 1999(2, 4)
Gwent Records
1988 Greenmoor Pool 1 in song 16 Mar– end May, & Jun. First record for Gwent
1989 Greenmoor Pool 1 in song Apr-Jun
  Monsanto 1 in song 5-7 Jun
1990 Greenmoor Pool 1 in song Mar-Jun
1991-1993 No records    
1994 Uskmouth 1 in song Feb-Mar & Oct-Nov
    1 Male trapped 30th Sept
  Greenmoor Pool at least 1 male in song Apr-Jun
    possible female Several dates
  Llanwern Steel up to 2 males in song Jun
  Magor Reserve 1 in song 19 Aug
1996 Greenmoor Pool 1 male 22 Mar-Jun
    2 males mid-May
  Llanwern Steel 2 in song May-Jun
  Uskmouth 1 Apr-May
  Monsanto 1 Apr-May
  Uskmouth 1 male trapped, orriginally caught and ringed at Littleton upon Severn, Avon 14/06/94 11 May
1997 Llanwern Steel 1 in song 8 Mar-10 May & 18-27 Dec
  Uskmouth West 1 31 Mar-3 May
  Uskmouth East 1 on 5 dates Jul-Dec
  Ringland way 1 in song 9 & 25 May
1998 Uskmouth up to 3 singing 22 Feb-14 Jun
    Female trapped 28 Aug. First confirmed female in the county.
    2 Aug-Dec
  Llanwern Steel 1 in song 30 May
  Alphasteel up to 3 in song May
  Ringland Way 1 in song 21 Mar
1999 GLWR Uskmouth at least 2 Jan, May-Jul & Sep-Nov
  Llanwern Steel 2 Mar-Apr
  Ringland Way 1 Mar-May
  Greenmoor Pool 1 Mar & Jun
2000 GLWR Uskmouth at least 7 singing males May
  Llanwern Steel 1 Mar-May
  Ringland Way 1 14 Apr
  Greenmoor Pool 1 13 May
2001 GLWR up to 4 in song Spring
    3 young fledging First confirmed breeding in the county
    nesting female Originally caught and ringed at Uskmouth in 1998
    female trapped Oct, ringed Thantcham, Berkshire in Aug 2000
  Liswerry Pill Bridge 1 Apr-May
  Nash Treatment Works   Apr & Jun
  Greenmoor Pool   Apr & Dec
  LLanwern Steel up to 3  
2002 Newhouse 1 holding territory from at least 21st April - 24th May
  Magor Reserve 1 Seen 25 May

Cetti’s Warbler now seems to be extending eastwards with records from Magor Marsh and Newhouse, Chepstow in 2002. So please keeps your eyes and ears open.

All records of Cetti’s Warblers are of interest. If on GLWR, please be as precise as possible with regard to location within the reserve, so that we can try to establish exact numbers. If you see or hear Cetti’s away from GLWR area, these are of particular interest

If in doubt, please send in all records of Cetti’s Warblers in the county. If there is a query, Chris Jones or someone else will be in touch.

  1. Cramp, Stanley (1992). Birds of the Western Palearctic, Volume VI, Warblers
  2. Green, Jonathan (2002). Birds in Wales 1992-2000
  3. Gwent Data taken from Annual Reports between 1988 and 2000
  4. Hurford, Clive & Lansdown, Peter (1995). Birds of Glamorgan

Reports of Field Trips

Brian King and George Noakes

Gilfach Reserve and Gigrin Farm, Saturday 13th April.

Expected birds did not show on this visit and it was thought that the continuing cold weather contributed to the quiet time. However the walk around the reserve was pleasant and displaying Red Kites were seen on several occasions, sunlight catching their plumage to great effect.

Gigrin Farm was busy with all hides full but we were rewarded by fine views at feeding, with some 50 Red Kites gathering together with the usual Buzzards and corvids. During the feeding session, a pair of Grey Herons took up station at the edges of the field taking advantage of dropped scraps. A small bird feeding station has been set up and five Yellowhammers were watched at close quarters.

The Skirrid, Saturday 20th April, leader Gerry McQuade.

A small group met for this walk in poor weather at the outset, but clearing rain enabled us to enjoy the woodland and the reward of a Peregrine in the rock face at the top. Chiffchaff, Willow Warbler, Blackcap, Tree Creeper and Green Woodpecker were watched along the way, but the continuing cold seemed to be keeping numbers in check.

GLWR Goldcliff, Sunday 28th April, leader Chris Jones.

A large group supported this popular walk on a very windy and cold morning though the early rain had stopped. The poor conditions kept bird numbers low but the following were seen: Dunlin, Greenshank, Oystercatcher, Whimbrel, Shelduck and Little Ringed Plover. Highlights were provided by views of the Ring-necked Duck that had been present on the reserve for some time, and a Short-eared Owl was watched as it was being mobbed.

St Mary’s Vale, Abergavenny, Saturday 11th May.

Despite the 5 a.m. meeting time, 11 members met Steve Butler for the dawn chorus walk in this beautiful valley. The discovery of a Golden Oriole on the walk at this location on 14th May 2000 was a definite incentive! Conditions were good and, with ears and eyes alert, we slowly made our way through the wood then descended through more open habitat just below the Sugar Loaf, finishing at 10 a.m. We ended with the following list:

  • Common Buzzard 4
  • Meadow Pipit 6
  • Garden Warbler 8
  • Treecreeper 4
  • Kestrel 1
  • Wren 9
  • Blackcap 7
  • Jay 4
  • Cuckoo 4
  • Dunnock 5
  • Wood Warbler 20
  • Magpie 1
  • Tawny Owl 1
  • Robin 12
  • Chiffchaff 2
  • Jackdaw 1
  • Swift 5
  • Redstart 7
  • Willow Warbler 18
  • Carrion Crow 2
  • Green Woodpecker 1
  • Whinchat 7
  • Goldcrest 4
  • Raven 4
  • Great Spotted Woodpecker 3
  • Stonechat 2 pairs
  • Pied Flycatcher 7
  • Chaffinch 15
  • Skylark 1
  • Blackbird 9
  • Blue Tit 7
  • Linnet 10
  • Swallow 4
  • Song Thrush 4
  • Great Tit 8
  • Yellowhammer 3
  • Tree Pipit 10
  • Mistle Thrush 2
  • Nuthatch 3

Mynyddislwyn, Saturday 18th May, leader Richard Clarke.

Heavy, driving rain greeted the group for this new upland walk and it was decided to brave the elements to get an idea of the area. The rain eased and the walk proceeded through varied habitat and the following were seen: Goldfinch, Linnet, Redstart, Treecreeper, Yellowhammer, Chiffchaff, Willow Warbler, Blackcap, Pied Wagtail, Tree Pipit, Kestrel, Buzzard, Raven and Curlew. The fine views and mature woodland added interest to a place I am sure we will visit again.

News from the Gwent Levels Wetlands Reserve

Kevin Dupé, Assistant Warden

After much searching we have finally been able to appoint a replacement for Adam – talk about ‘irreplaceable’! Tony Pickup will take up the post of Warden here at the beginning of July. Tony will be on a long-term secondment from RSPB. He has been warden at Gwenffrwd for over 20 years and has been RSPB Cymru’s Lapwing Recovery Project Officer for the last 4 years. He brings a lot of experience to the job and I look forward to working with him.

In the absence of a warden, the breeding birds survey for the Reserve was put out to tender. Andrew Henderson won the contract. Initial results are encouraging with Lapwing numbers having doubled since last year with over 30 pairs breeding. Ringed plover have bred for the first time on the Reserve. Garganey did not arrive until his 3rd visit, but up to 4 males have been seen and pairs have been seen on the Uskmouth Reedbeds, Uskmouth Phase II and the Saltmarsh Grasslands.

Many interesting birds have passed through this spring, but I am sure you can read about them elsewhere in this issue of The Dipper. A female Marsh Harrier was present for several days and on 24th April I saw her flying across one of the old reedbeds with reeds in her talons. She landed on a piece of rough grassland next to the reedbed and was immediately mobbed by six Magpies! Was she intentionally carrying nesting material or had she picked them up with a prey item?

The reedbed that the Marsh Harrier was flying over is a very dry one with quite a bit of scrub. Last year the reeds were very stressed in the spring drought and the reedbed was still brown in June! The old sluice, which controlled the water level when the lagoon was used for disposing of Pulverised Fuel Ash from Uskmouth Power Station, was defunct. Over the winter we had this repaired and we are now able to hold water in the reedbed. This should ensure that the reeds grow healthily and reduce scrub encroachment. A knock-on effect from this is that the Goldcliff Ringing Group will need a boardwalk in order to use their ride through this reedbed. CCW has purchased a re-cycled plastic boardwalk which we will install after the breeding season. The boardwalk will also enable us to take groups out into the reedbed. I have also been using the ringers’ ride as an excellent location to site a moth trap overnight and the boardwalk will enable me to continue to do this.

The ringers recently straightened their ride in readiness for the boardwalk and cut down a sallow. This revealed larval borings of a goat moth caterpillar. Searches of nearby sallows showed that they too were riddled with goat moths. We caught an adult of this Nationally Notable species last year on the Reserve. This was the first adult to be recorded in the county since 1871! Management of this reedbed will have to take account of the needs of all taxa that are present.

A very serious incident took place at the Goldcliff Lagoons on April 20th. A white Land Rover drove down the cart track that runs along Mireland Pill Reen. One of the occupants climbed over the barbed-wire fence that runs along the embankment around the lagoons, down to the waters edge and fired two shots over the water with some kind of firearm. The obvious intention, and result, was to disturb all the birds. These included little-ringed plover – a Schedule 1 species under the Wildlife and Countryside Act. A bird watcher who witnessed this wrote down the vehicle registration and was then threatened with assault. Unfortunately the police are unwilling to take any action, but we are pressing them to do so.

If you see anybody shooting on the Reserve please do not approach them. Please phone the police as soon as possible – by dialling 999 if they are still on the site. If you are reporting an incident after the event telephone Newport Central Police Station on 01633 244999. If it is safe to do so write down vehicle registrations and descriptions – use your binoculars rather than approaching closely. Shooting is only allowed off the extreme western part of the Uskmouth foreshore by members of Newport Gun Club. They are allowed to use the cycle track from the power station gates as access. If on the cycle track their guns should be in cases or un-cocked and not loaded. They can only shoot in the shooting seasonwhich runs from 1st September until the end of February. Newport Gun Club have not shot at Uskmouth for the last two winters. Anybody else shooting on the Reserve (even with ‘just’ an airgun) is doing so without the owners’, i.e. CCW’s, consent and is committing offences such as armed trespass, discharge of a firearm in a public place and possibly offences under the Wildlife and Countryside Act.

Provisional estimates of breeding pairs of Lapwing, Redshank and Little Ringed Plover on the reserve this year are as follows:

  • Lapwing: Two pairs near Uskmouth, 22 pairs on the Saltmarsh levels and 13 pairs at Goldcliff Lagoons, making a total of 37 pairs.
  • Redshank: 14 pairs on the Saltmarsh levels plus 9-10 pairs at Goldcliff Lagoons, making a total of 23-24 pairs
  • Little Ringed Plover: One pair on the Saltmarsh levels plus six pairs at Goldcliff Lagoons, giving a total of seven pairs.

Committee Commentary

Committee Composition: The April meeting received the resignations of both Gill Jones as Membership Secretary as of September, and Field Secretary Brian King. They will be missed for their valuable contributions to the Society. Helen Parry Jones has indicated her willingness to take over as Membership Secretary, and Steve Butler that of Field Secretary.

Goytre House Wood: The pond in Goytre House Wood has been cleared, nest boxes erected and the fence erection nearly completed (at the time of the meeting). Plans are afoot for improved access and signage.

Birds of Gwent: Atlas surveys continue with more tetrads being allocated in 2002. Next year will be a mop-up year for sparsely covered areas and Outdoor walks will be targeting these areas too.

Membership Matters: A long discussion centred on ways to stop the slow decline in membership and attendance at indoor meetings It was recognised that retention of existing members was probably more important than energetic recruitment campaigns. Greater numbers introduce their own problems, e.g. causing a change in venue if we outgrow the Goytre Village Hall. In an endeavour to overcome the charge that ‘GOS is an unfriendly Society’ we will, at the start of every meeting, call for new members/visitors to make themselves known to Committee members who will be wearing name badges. Helen will also be publishing a Rogues Gallery in forthcoming Dippers to enable members to put Committee member faces to names.

Further initiatives will be introduced during the year but it would appear that the new posters at indoor meetings are proving useful. Further feedback is always welcome!

Are you a fluent Welsh Speaker

Helen Parry Jones

Recently I was approached by a television company doing a wildlife series for S4C, which was to cover the Gwent Levels Wetlands Reserve. They were dealing with CCW, but also wanted someone from the local bird club (GOS) to participate. I e-mailed to those members whose addresses I had, and put a notice on the website. Unfortunately, no one came forward, so GOS will not be represented in the programme. Should a similar situation arise again, it would be useful to have a list of willing Welsh speakers. If this applies to you please let me know.

Cuckoo Tricks with Eggs and Chicks (1)

N.B. Davies, summarised by Helen Parry Jones

Discussing Cuckoos with fellow GOS member Phil Thompson, he brought to my attention a fascinating article in a recent issue of British Birds. Below is my attempt to summarise this article.

Host-specific female Cuckoo gentes (races) In Britain over 50 species have been recorded as occasional hosts for Cuckoos but five main hosts account for 90% of the parasitised nests reported to the BTO Nest Record Scheme:

Reed Warbler (Marshland)
Meadow Pipit (moor & heath)
Dunnock (Wood & Farmland)
Robin (Wood & Farmland)
Pied Wagtail (Open Country)

Cuckoo is not a common bird, so even for favoured hosts parasitism is about 5% of nests overall, though locally it may range from 0-60%. In 1987, there were estimated to be 21,000 breeding females in Britain.

Individual females specialise in one host, and only use another if the preferred host is in short supply. Effectively there are different “host races” of females, called gentes (singular gens). Host preference is carried in the female lineage, and it is the cross-mating with males that maintains the Cuckoo as one species. DNA analysis of 136 Cuckoo chicks, showed that each female was largely faithful to one host whereas 37% of males had offspring in the nests of more than one species, so they must have mated with females of more than one host specialisation.

To examine this issue further, DNA from Cuckoos of the Reed Warbler, Dunnock and Meadow Pipit gentes was examined. No differences were found in the nuclear DNA (inherited from both parents) between gentes. However differences were found in the mitochondrial DNA which is inherited from the female. The degree of differences suggests that these gentes last shared a common ancestor about 80,000 years ago.

Host-egg mimicry. Each Cuckoo gens (female “host race”) lays a distinctive egg that tends to match the egg of its chosen host, and individual females lay the same egg type throughout their lives. It is assumed that daughters lay a similar egg type to that of the mother. In which case genes influencing egg type would be determined by the female, otherwise cross-mating by the males would disrupt the mimicry. Female birds have a unique sex chromosome, W, and it is possible that genes relating to egg colour are contained within this.

If daughter follows mother, how does the daughter know where to lay her eggs? The most likely way is by “imprinting” on the host species and/or habitat, i.e. learning the characteristics of each and returning to these when she comes to breed.

Cuckoo tactics. The female Cuckoo monitors the host nests in her territory, and lays her eggs during the host’s own laying period. She lays on alternate days, in the afternoon or early evening. Before laying she perches in a tree nearby for up to 2.5 hours. She then glides to the nest, picks out an egg, and holding it in her bill lays her own egg directly into the nest and then flies off. The whole process takes about 10 seconds. If a clutch is complete, the female will depredate a whole clutch to force the hosts to lay a new clutch, which will then allow her to lay.

The Cuckoo’s egg requires about half a day’s less incubation than host eggs, and consequently usually hatches first. An egg takes 24 hours to be fully formed from ovulation to laying-down of the shell. By laying on alternate days, the female is likely to carry a fully formed egg in her oviduct for a day before it is laid. This perhaps gives the Cuckoo chick a head start.

The young Cuckoo chick, naked and blind, ejects any eggs and young from the nest. The host parents then feed it in the nest for about three weeks, and for a further two to three weeks after fledging. For a host such as Reed Warbler, this is two weeks longer than it takes to raise its own brood. If a host has a Cuckoo egg in its first nest of the summer, it will have no time to breed again in the season and will have no reproductive gain from five weeks hard work.

Co-evolution. In response to parasitism, the host should develop defences. In turn, this should select for the evolution of improved trickery by the Cuckoo, which should provoke further improvements in host defences etc.

In practice, the Cuckoo lays an egg in a host nest. Some hosts, perhaps previous or current hosts recognise it as foreign and reject it. Each Cuckoo gens evolves to lay eggs that mimic those of preferred host. The host reduces the variability in colour in its clutch and is better able to detect odd eggs, the Cuckoo develops better mimicry or moves on to a new host.

Model egg studies show that Reed Warbler and Meadow Pipit rejected eggs that didn’t match whereas Dunnock accepted different eggs. This may be because Reed Warbler and Meadow Pipit are established hosts and have developed egg rejection, whereas Dunnock is a new host and has not yet developed such defences.

If a Cuckoo egg was placed in a Reed Warbler nest before the clutch was started, even if it mimicked that of the host species, it was always rejected, so the Cuckoo waits until the host starts laying.

Cuckoo eggs are slightly smaller than Skylark eggs (22.7x16.9mm) and are much smaller than those of non-parasitic Cuckoos of similar body size which lay eggs about the same size as those of Mistle Thrush (31.2x22.3mm(2)).

There are three possible explanations at to why the female removes an egg. The host can count, though experiments don’t confirm this. The female may hope to improve the incubation of her own egg. The female has a free meal. She doesn’t remove all the eggs once she has laid hers because hosts desert if the clutch is reduced to one egg. However they don’t desert a single chick which is why it is the chick and not the female Cuckoo earlier during laying, that has to eject the host eggs.

It has been shown that if a Cuckoo is seen at the nest by the host species, egg rejection is increased. Thisperhaps explains the rapidity of the laying visit.

Flexible host defences. Why do hosts need to be alerted to reject a Cuckoo egg? The hosts may damage their own eggs in an attempt to eject a Cuckoo egg. Also they may make a recognition error when the Cuckoo egg is a good match, and reject one of their own in error. Perhaps it only pays the host to reject and incur these costs above a certain frequency of parasitism. Parasitised populations show a greater rejection of eggs than unparasitised populations and this seems to be behavioural and not due to genetic differences between the populations.

Hosts evolve in response to Cuckoos. There is now good evidence that host defences select for both the Cuckoo’s egg mimicry and its laying tactics. Have host defences evolved specifically in response to Cuckoos? If so, small birds with no history of Cuckoo parasitism would show no rejection of foreign eggs. Two such groups would be hole nesting birds (Tits etc) and birds that feed young on seeds. Little or no egg rejection is shown by species in these groups. Comparisons of closely related species suggest that egg rejection is related to experience. The open-nesting Spotted Flycatchers are occasional victims of Cuckoos and show strong egg rejection whereas hole-nesting Pied Flycatchers do not, even when the eggs are very different from their own. Similarly, finches feeding young on seeds do not reject eggs whereas those feeding young on insects do.

A comparison between suitable and unsuitable species also shows that Cuckoo hosts change their egg markings. Species exploited by Cuckoos show less variation of eggs within a single clutch and more variation between clutches of different females than do species with no history of Cuckoo parasitism. This makes it more difficult for Cuckoos as it is easier for hosts to identify foreign eggs.

New and old hosts. The above suggests that egg rejection has evolved specifically as a result of parasitism. Currently Dunnock parasitism is 2%, similar to Meadow Pipit (2.5%) and higher than Pied Wagtail (0.4%). The Dunnock’s lack of rejection may be explained by the fact that this is a new host species that has yet to evolve a counter measure, or that parasitism has always been low in this species so there has been no need to evolve a counter strategy. Meadow Pipit and Pied Wagtail may have been subjected to stronger selection in the past.

Model egg experiments show that there are some suitable host species, exhibit stronger rejection than do many of the current favourite hosts – Willow Warbler, Chaffinch, Reed Bunting, and Yellow Hammer. If egg rejection evolves in response to parasitism, it implies that these were once favoured hosts that now retain rejection as a legacy.

The implication is that the Cuckoo changes the use of host with time. Evidence for this comes from Japan where 60 years ago the most common gentes were those specialising on Bull-headed Shrike, Great Reed Warbler and Meadow Bunting. The first two continue to be favoured hosts whilst the bunting, although abundant, has become a rare host. In its place a new gens has evolved, parasitising Azure-winged Magpies. In recent years this species has spread to higher elevations and has come in to increasing contact with Cuckoos. The first record of their parasitism was in 1956, since then they have become one of the main hosts with parasitism levels of 30-60% in several areas. In some areas, the magpies are already beginning to “fight back” and now reject Cuckoo eggs at 30-40% of nests. As this response has been so rapid, it is possible that this species has been parasitised in the past and its renewed contact with Cuckoos has “switched on” the rejection instinct.

The initial step to the creation of new gentes must be occurring continuously, with Cuckoos laying eggs in alternative host nests. However it is only sufficient if these “wrong” hosts accept a good proportion of the eggs and only if several females switch to it at the same time, will a new gens be created.

Why accept a Cuckoo chick? Although most hosts reject foreign eggs, there is no evidence that any host ever rejects any Cuckoo chick. This is extraordinary as there are 3 cues to indicate to a Reed Warbler, for example, that it’s not its own: its too big, its gape is wrong (orange rather than yellow} and it lacks tongue spots. However the host adults continue to accept it. The acceptance appears not to be due to size or gape colour, but more to do with auditory signals.

Why accept the chicks but not eggs? Experiments with Great Reed Warbler suggest that the hosts come to reject foreign eggs by first learning the appearance of their own eggs during the laying of their first clutch. If they the encounter a different egg, they reject it. If the hosts are unlucky, and are parasitised during their first clutch, they may learn that this is part of their “own set” and so would accept that type as well as their own for ever more. This cost of mis-imprinting is not too serious, because in most of their future breeding attempts their clutches will be unparasitised and the young they raise will be their own.

However this strategy would be a disaster for the Cuckoo host if applied at the chick stage. A host parasitised at its first breeding attempt would imprint only on the Cuckoo chick and see its own chicks in future broods as being foreign, and reject them. The best option would seem to be to “to accept any chick in my nest”.

How does the one chick get fed so much? Having apparently decided to accept any young in the nest, experiments indicate that the feeding stimulus is mainly auditory, with the incessant call of the young Cuckoo stimulating the adults as if four young were being fed. Since reading this article, a couple of other things have been brought to my attention.

Adult Cuckoo feeding juvenile Cuckoo. Whilst it is commonly believed that Cuckoos don’t ever feed their young, a note in British Birds(3) indicates that this is not always true.

On 29th-30th May 2001, in South Yorkshire, Meadow Pipits were observed feeding a young Cuckoo. The next day, an adult male Cuckoo was observed feeding the youngster, until the adult was driven away by the Meadow Pipits. The only other report of adult Cuckoo feeding young was reported in 1911(4)

Help wanted with begging calls of Cuckoo chicks(5). Professor N B Davies, (author of the above article) is wanting help with his Cuckoo studies, in particular with recordings of begging calls. He wants to see whether Cuckoo chicks call in different ways to stimulate different hosts to bring as much food as they would for a whole brood. If you find a Cuckoo egg or chick in the nest of any host (especially Reed Warbler, Meadow Pipit, Dunnock or Robin) and would like to help, please phone Nick Davies (01223 245253) or Stuart Butchart (07855 953697). They would particularly like you to record young Cuckoos from hatching to 12 days of age, though older nestlings would also be useful. If you can help, a Poyser book will be a thank you.

  1. Cuckoo tricks with eggs and chicks. British Birds, 95(3): 101-115
  2. Harrison, C. & Castell, P. (1998) Bird Nests, Eggs & Nestlings of Britain & Europe p 187, 206 & 369
  3. Smith, K. (2002) British Birds 95(4)
  4. Birds of the Western Palearctic, Vol. IV, p 412
  5. Davies, N.B. (2002) Still gegging for help with Cuckoos. BTO News No. 240, May-June: p 22
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