Worcestershire Record No. 2 April 1997 p. 10

BTO BIRD SURVEYS

Harry Green

Breeding Bird Survey
Skylarks
Woodlarks
Breeding Sawbill Survey
Herons

Breeding Bird Survey

This survey is organised by the BTO with funding from JNCC and RSPB. The survey work is undertaken by volunteers. The survey is based on 1x1 km squares of the national grid selected randomly by the BTO computer. The survey is now in its fourth year and over 2,000 squares will be covered in UK in 1997. This is a major survey which is expected to run "for ever" and it is designed to keep track of UK breeding bird populations. Observers make three visits to their square, one to plan two transect paths and to record habitat, and two to undertake the survey by walking the transects and plotting the birds seen or heard singing on a diagram. The visits are made early (April to mid-May) and late (mid-May to end June) and four weeks apart.

To date Worcestershire has 46 squares to cover and I list them below together with years covered so far. A few more have been added each year since the start of the survey! So far most squares have been covered, although at the end of March 1997 I still await the 1996 paperwork from a few observers!

10k Squ	Square	name	1994	1995	1996	1997

SO93	SO9837	Mart	no	yes	yes	+						
SO86	SO9861	Shep	yes	yes	-yes	+
SO96	SO9467	Brow	Yes	yes	yes	+
SO85	SO8152	Step	yes	yes	yes	+
SO97	SO9878		no	no 	no	vac
SO66	SO6665	Grun	yes	yes	yes	+
SO93	SO9735	Whe	yes	yes	yes	+
SO93	SO9334	Whe	yes	yes	yes	+
SO66	SO6067	Coat	yes	yes	yes	+
SO86	SO8469	Hum	yes	yes	yes	+
SO87	SO8470	Hum 	yes	yes	yes	+
SP04	SP0746	Cott	yes	yes	yes	+
SO93	SO9630	Pepl	yes	no	-yes	+How
SO93	SO9237	Will	yes	yes	yes	+
SP04	SP0243	Hodg	yes	yes	yes	+
SO97	SO9476	Yeg	no	yes	yes	+
SO85	SO8354	Jone	yes	yes	yes	+
SO74	SO7444	Birk	yes	yes	yes	+
SP04	SP0042	Hodg	yes	yes	yes	+
SO77	SO7475	Tayl	yes	yes	yes	+
SO84	SO8745	Hods	yes	yes	yes	+
SO86	SO8462	Gane	yes	yes	yes	+
SO77	SO7374	Tayl	yes	yes	yes	+
SO84	SO8642	Lowe	yes	yes	yes	+
SO77	SO7472	Evan	no	yes	yes	+
SO77	SO7074	Robe	yes	yes	yes	+
SO84	SO8549	Step	yes	yes	yes	+
SO66	SO6566	Grun	-	yes	no	+
SO97	SO9877		-	no 	no	vac
SO94	SO9844	Mant	-	yes	yes	+Pep
SO86	SO8865	Mick	-	yes	yes	+
SO95	SO9454	Farm	-	yes	yes	+
SO94	SO9647	Pepl	-	-	-yes	+
SO97	SO9971	Watt	-	-  	no	+Hut
SO97	SO9278	Harr	-	-  	-yes	+
SO95	SO9057	Week	-	-  	yes	+
SO94	SO9840	Lenn	-	-  	yes	+
SO84	SO8249	Mitt	-	-  	yes	+
SO94	SO9848	Rat	-	-	-	+
SO75	SO7653	Dunc	-	-	-	+
SO66	SO6160	Mick	-	-	-	+
SO76	SO7461	Mile	-	-	-	+
SO66	SO6061	Mick	-	-	-	+
SP04	SO0347	Cott	-	-	-	+
S087	SO8976	Summ	-	-	-	+
SO84	SO8947	Hero	-	-	-	+
Key:
'Yes' mean survey done.
'No' means the opposite.
'-' means not in the survey for a particular year.
'-yes' means I haven't received the paperwork yet.
Under 1997 '+' means I have a surveyor for the year, I hope!
'vac' under 1997 means I can't find an observer.
Apologies for abbreviated observer names which is to save space on the computer.

There are two problem squares in Rubery and Frankley (South Birmingham) which nobody wants to survey - I wonder why. If anyone would like to have a go please let me know as soon as possible.

It is quite a task to find observers for this survey. If anyone would like to take part in future years please let me know. There will almost always be vacant squares. BTO are likely to add more squares next year, and observers may be unable to continue surveying their present square.

Skylarks

As readers have probably heard the numbers of skylarks both wintering and breeding in Britain have declined markedly in recent years. The BTO Common Bird Census shows a decline of about 50%. The decline seems to be associated with intensive farming and disappearance of food and nesting sites. Autumn (rather than spring) sowing has led to the disappearance of winter stubble or similar (which supplies winter food). The dense tall growth of autumn sown cereals, and of fertilized grassland, is, by spring-time, unsuitable nesting habitat. It is also short on invertebrate food for the birds.

To determine exactly what is happening to UK skylark populations the BTO is organising important surveys of both wintering and breeding birds.

These surveys are based on randomly selected 1x1 km squares of the national grid. In Worcestershire SO6167, SO8134, SO8332, SO9258, SO9966 are being covered for both winter and summer surveys. SP0142 and SP0646 are covered by the winter survey only.

The summer survey is based on mapping singing birds together with collecting habitat information on field use and size, and on boundaries. The winter survey is of feeding flocks and similar habitat data. Analysis of the survey data should give a much clearer picture of skylark numbers and on the habitat structure and quality in preferred areas.

Woodlarks

The BTO is organising a repeat national census of breeding Woodlarks following on from the 1986 survey. The national range is re-expanding after a long decline and there is a good chance that Woodlarks will return to breed in Worcestershire. The most likely places are on the sandy soils of NW Worcestershire, especially near Kidderminster and over the border into Staffordshire near Kinver. However, Woodlarks once bred elsewhere in Worcestershire as revealed by a compsite map prepared from all the records in the Worcs BRC, so it is worth keeping eyes and ears open, especially along the Malvern Hills and on Bredon Hill, and wherever there are light soils.

The preferred breeding habitats are where there is open broken soil (the birds form a deep nesting cup on the ground) with a scattering of trees. The BTO 1986 survey showed that most territories contained bare soil or very short grazed grass, exceeding 5% of the territory area in most cases. Canopy cover is usually sparse, and shrub cover rarely more than 20%. Although typically birds of open heathland Woodlarks often breed on managed land. Nowadays they are often found in forestry plantations where the tree height is 2 metres or less. In plantations they can be found along rides or on other areas of open space. They do use other open habitats and there are records from cultivated cereal fields, horse paddocks, on set-aside land, and small-holdings of plant nurseries. Some observers think that a patch of soil with correct root-free friable structure is a most important feature within a territory as it permits the bird to form a deep nest cup.

The Woodlark's song is lilting and beautiful (nothing like skylark song but perhaps reminiscent of a tree pipit) and they have a soaring song flight. The main song period is from February through to mid-May and searches of suitable habitat are most likely to reveal the birds during this period.

Please look at suitable habitat in your area. If you think you have found a breeding woodlark please contact me as soon as possible so the survey forms can be completed. At present I am assuming there are no breeding woodlarks in Worcestershire.

Breeding Sawbill Survey

There has been a considerable expansion of breeding range of both Goosanders and Red-breasted Mergansers in recent years and this is being monitored by a British Trust for Ornithology Survey. Following the presence of large numbers of sawbills in the county this past winter we may have to revise our ideas that no sawbills breed here! I have heard rumours that sawbills may have bred in the Teme valley in recent years. If anyone has any records of summering birds for 1995 and 1996 I should be grateful if you could let me know. The survey is being funded by DoE and the Environment Agency.

Ideally, for the survey, we need to know whether the birds were definitely present or absent during 1995 and 1996, and whether they are present or absent during the 1997 breeding season. If present did breeding definitely occur (nests, young seen, courtship displays) or were the birds simply "present".

Records for all these years should be sent to me by end May 1997 if possible. PLEASE GET IN TOUCH WITH IF YOU find sawbills this year or if you found them in previous years. All records of sites will be kept confidential.

Unfortunately fishermen often regard sawbills as unwanted competitors and licences for shooting them may be sought. In this context it is most important that we keep a records of our population and are on the look-out for illegal "control" measures being applied.

Herons

The Heronries Census is the longest-running bird census is Britain, and for much of the world! It started in 1928 and has been running along a low key ever since. Graphs of fluctuations in heron populations - usually a crash after a bad winter and then a return to a ceiling - often appear in textbooks. In recent years Worcestershire counts have been a rather haphazard and we have failed to make a count in some years. This is a pity because new heronries have been established and old ones have vanished.

I badly need a heronry counter - volunteer? The aim is to record the number of occupied heron's nests at as many sites as possible every year. Herons breed early and the nests can be seen before the leaves come out on the trees. A best estimate of number of nests is added to the data base. The results of the counts are recorded on a special card issued by BTO.

If you would like to become Worcestershire's official heronry counter please get in touch with me as soon as possible.

 
WBRC Home Worcs Record Listing by Issue Worcs Record Listing by Subject