21.08.12. Birdlog

21.08.12. Birdlog

An adult and 3 Water Rail chicks, 3 Snipe, 2 Green Sandpiper and 1 Common Sandpiper, 5 Black-tailed Godwit, 3 Whimbrel, 7 Ringed Plover and interestingly 80 Golden Plover flying to the Score from the south-east (MT). A juvenile Mediterraean Gull came into the gull roost (IL). 3 Yellow Wagtail and 4 Swifts moving through.

Water Rail chick. Image by WSM.

A Hobby chasing Swallows over Godscroft Lane was a welcome surprise for the observer (PC), and close by but just outside this area was a Tawny Owl caught in the beam of my car headlights (JS,WSM).

Observer: Paul Crawley, Arthur Harrison, Ian Igglesden, Mike Turton, Sparky, WSM.

How to Score on Frodsham Score again!

Cheshire has lost one of the UK’s top ten wetlands!

 It is true that Cheshire used to have 2 of the top ten wetlands in the UK for overwintering wildfowl and waders.  For many years the Dee Estuary has been the 7th or 8th most important wetland for waterfowl while the Mersey has ranked 9th in country.  However, as table 1 shows, since 2007 the Mersey has dropped out of the top ten and is now ranked 17th, while the Dee has remained at number 7.

Table 1 5 yearly average of waterfowl on the Mersey Estuary and Dee Estuary

Mersey

Dee

Year

Average

rank

Average

rank

2009-10

63,865

17

113,182

7

2008-09

67,789

17

119,813

7

2007-08

79,504

13

129,271

7

2006-07

85,801

11

134,002

7

2005-06

94,025

10

148,003

7

2004-05

100,923

10

148,986

7

2003-04

105,976

9

144,365

7

2001-03

104,218

9

125,623

8

2000-01

108,635

9

123,010

8

1999-2000

104,784

9

121,954

8

1998-99

109,475

9

128.341

7

1995-96

99,448

9

123,855

7

 At the CAWOS meeting on the 7th October 2011 Neil Calbrade (WeBS Reserarch Ecologist, BTO) gave a very interesting talkspeculating about why numbers of birds on the Mersey seem to have fallen recently.  Between 1996 and 2006 I helped with the monthly waterfowl counts on the Mersey so I was keen to find out why the numbers had fallen so sharply since I’d stopped, surely I wasn’t to blame!

 Neil said that there had been an increasing general trend for birds flying from Siberia and Europe for the British winter to stay on the east coast rather than move onto the west coast.  This is probably due to milder winters meaning it no longer pays to move to the west coast, and this could be the reason why numbers of birds on east coast wetlands have increased while those on the west coast have fallen.

 How do we know this?

We know this because each month, on a particular day, birdwatchers count the waders and ducks present on every wetland in Britain.  The counts, known as the Wetland Bird Survey (WeBS) are coordinated by the BTO and provide a massive data set.  (see http://www.bto.org/volunteer-surveys/webs/publications/annual-reports) .  Each year they produce an annual report that summarises for each species and wetland the numbers of birds present each winter and gives a rolling 5 year average for sites and species.  This means that the affect of unusual events or counts do not distort the data.

 I have used the WeBS count data to look at the top estuaries and tracked the number of wintering birds from 1995-96 to 2009-10. There is a clear trend: west coast estuaries have been losing birds, while those on the east coast now hold more birds.  Table 2 shows Britain’s top wetlands and how those rankings have changed since 1995-96. Two estuaries on the east coast, North Norfolk and Breydon Water, have shown a remarkable 143% increase while two wetlands in the west, the Mersey Estuary and Lough Neagh, have shown very significant declines. So it would seem that there is a clear trend and the Mersey is being affected by this, more than most other west coast estuaries.

 Table 2 Britain’s Top Wetlands

Site

1995-96

rank

2009-10

Rank

coast

Change

Wash

522,521

1

387,024

1

East

20%

Ribble

269,132

2

236,881

2

West

-12%

Morecambe Bay

221,251

3

202,735

4

West

-8%

Humber

161,973

4

150,192

6

East

-7%

Thames

151,578

5

180,681

5

East

19%

Solway

136,132

6

98,631

9

West

-28%

Dee

123,855

7

113,182

7

West

-9%

Lo.Neagh/Beg

102,541

8

52,441

20

West

-49%

Mersey

99,448

9

63,865

17

West

-36%

N Norfolk

83,590

12

203,480

3

East

143%

Breydon Water

43,281

26

105,070

8

East

143%

 Why are Bird Numbers Falling on the Mersey?

Since the CAWOS meeting I have rejoined my friends counting on the Mersey and they have confirmed that several species have shown very significant declines.  Table 3, below, shows that species like Wigeon, Pintail, Golden and Grey Plover have declined and are no longer of national importance.  Other species like Teal, Black-tailed Godwit, Redshank and Dunlin have all declined significantly but are still of international or national importance.

 Table 3 Bird Species of National importance that use the Mersey estuary

95-96

rank

2009-10

rank

Great Crested Grebe

126

 *

 *

Canada Goose

3,015

1

Shelduck

5,039

5

16,163

1

Wigeon

11,752

7

 *

 *

Teal

11,667

2

6,397

3

Pintail

2,744

4

 *

 *

Golden Plover

3,070

19

 *

 *

Grey Plover

1,012

20

 *

 *

Lapwing

11,680

11

5723

 *

Dunlin

44,300

2

35,549

2

Black-tailed Godwit

1,480#

6

1,465

14

Redshank

4,689

4

3,039

12

*No longer of national importance

#1999-2000 figure

 The BTO are concerned about these declines and have issued alerts for 11 of the 12 key species that winter on the estuary. (see www.bto.org/webs/alerts ) No one knows why the declines have occurred.  We know that over this time period pollution levels have fallen.  Has a cleaner estuary meant fewer birds?  Cleaner water should mean more fish and we know that salmon have now returned to the River Mersey to breed, so it is surprising that a fish eating species like Great Crested Grebes have also declined.  There may be other man made factors that we cannot detect, or perhaps just natural changes in the proportions of saltmarsh and mudflat and their position the estuary.  Certainly the main channel is very active and since my visit in January 2006 and my last visit in October 2011 the spartina in Manistay Bay has increased at the expense of mudflat.  It is hard to see that recreation has had much impact as the south side is still cut off from the outside world except for a few wildfowlers and the monthly duck counters.

 We do know that there is much interchange of birds between the Mersey and the Dee (and to a lesser extent, the Ribble and Alt estuaries). I have compared changes on the Dee with the Mersey. Figure 1 shows that, although the Dee has shown a boom in recent years while the Mersey was decreasing, the Dee is also now falling and at the same rate as the Mersey. It may be that there is a wider issue with the Cheshire estuaries and it is just that the Mersey started to decline first.

How to Score on Frodsham Score again!

The fact that is causing me most concern is that when I went on the count in October I was 30 years younger than the next youngest person!  There are 3 or 4 dedicated duck counters; some, like Graham Thomason, have been doing it since the 1960s while others have been doing it for a mere 20 years.  The group in October were all over 70 years old and most have at least one of their joints replaced, but they still turn out each month! Looking back at the WeBS records recent counts on the Mersey are often in brackets which means an incomplete count.  Therefore it could be that some of the decline is not an actual decline but a reflection of a lack of coverage. The existing team cannot cover such a big estuary and so we desperately need help.  The lack of counters is not the main reason for the apparent decline in the Mersey but it is a concern, and without reliable and complete counts it is hard to assess the issue fully.

 The Mersey Estuary needs you! Despite the decline it is still an internationally important wetland and there are still spectacular numbers of birds, with over 30,000 Dunlin.  Whooper Swans have been increasing recently and in amongst the Canada Geese that I saw in October was a Barnacle Goose and two Egyptian Geese.  Birds of prey are common with Peregrine always present and Merlin seen on most winter counts.  Hen harriers sometimes winter on the Mersey Estuary and the Frodsham Marsh Harriers also hunt the area.  Little Egrets have increased and there is usually something out of the ordinary like Snow or Lapland Bunting or Wheatear.  I have even had a Redstart on passage.  Some of you might remember Frodsham’s purple patch in 1999 when a Terek, and then Broad-billed Sandpiper turned up within a couple of weeks of each other.  Where did they disappear off to? The Mersey Estuary.  So rarities do turn up and if you find one then you can have it to yourself as no one else will be able to get there until next month! What’s more is you can get closer to the wader flocks than you can on the Dee Estuary.

 We desperately need new birders.  There is no public access to the South side of the estuary, except once a month when we go through Stanlow Oil Refinery and get the ferry across the Manchester Ship Canal.  We then count all the waders in Manistay Bay, at Stanlow Point, in the River Gowy and at Ince and Frodsham Score.  Although the winter counts are the most important there is a count each month.  Counts in July and August in the late 1990s and early 2000s revealed a build up of up to 20,000 Shelduck making this most important moulting site in Britain for this species.

 The next count is on December 11th.  We will meet at 8am at entrance number 4 off Oil Sites Road, Stanlow Oil Refinery.  If you want to come please ring Graham Thomason on 0151 424 7257 or email me

dermot.smith@fsmail.net, or find the Mersey Estuary WeBS on the Facebook page. It is a big place and, although flat, walking to Frodsham Score is an 8 mile round trip so the counts usually takes about 6 hours from meeting to departing. We will publish the 2012 dates when available on the CAWOS website, in Bird News, on Facebook and wherever else we can.

 Please put your birding to good use and help us to maintain coverage of one of Britain’s best and most inaccessible wetlands.

Mersey WeBS 2012

Meet at Stanlow Oil Refinery visitors’ entrance, off Oil Sites Road.  Travelling from the East turn first left to the visitors’ entrance, under the railway line, left at the roundabout and we meet in the car park on the left at the following times, all dates are Sundays:

15th Jan 12noon tide 9M

12th Feb 10.30am 9.6M

11th March 9.30am 9.9M

8th April 9.30am 10.0M

20th May 8.30am 8.7M

24th June 11.30am 8.6M

22nd July 10.30am 9.1M

19th Aug 9.30am 9.4M

16th Sept 08.30am 9.5M

14th Oct 7.30am 9.3M

18th Nov 10.30am 9.4M

16th Dec 9.30am 9.9M

Bring warm and water proof clothes, wellington boots and your lunch.  Counts usually take about 6 hours and there are NO toilets!

If you want to come please ring Graham Thomason on 0151 424 7257 or Dermot Smith 01925 602397.

Dermot Smith