This introduction originally appeared in the Club's West Midland Bird Distribution Survey, published for private circulation in 1951.
INTRODUCTION
The need for a distribution survey of the more or less common birds to be found breeding in the three counties of Warwickshire, Worcestershire and Staffordshire has long been felt. Various methods involving sample counts were examined and discarded as being either impossibly laborious or so open to error as to be completely worthless. After a good deal of personal experiment a scheme was devised which would produce a general picture of distribution and at the same time avoid the necessity for specific quantitative surveys.
For the purpose of this survey the three counties were divided into 38 smaller districts, based in most cases on the boundaries of Rural District Councils. These districts, which vary from just under 14,000 acres in one case, to over 73,000 in another, are mostly between forty and sixty thousand acres.
For each district a known and experienced bird observer, or group of observers, resident in, or having a reasonably intimate knowledge of the district, was selected. The observers thus chosen were asked to assign each of the hundred species under review to one of the following seven categories :-
Not breeding regularly
A. Not known or recorded since 1946.
B. Observed irregularly (not every year).
C. Observed regularly (at least once every year). Not breeding.
D. Has nested on one or more occasions since 1946 but NOT every year.
Breeding regularly
E. Average density probably less than 10 pairs per 50 square miles.
F. Average density probably between 10 and 100 pairs per 50 square miles.
G. Average density probably over 100 pairs per 50 square miles.
Questionnaires were sent out in the late summer of 1950 and reports were received from all districts with the exception of the extreme north-west of Staffordshire (Newcastle-under-Lyme Rural District).
It is emphasised that the observers were asked to express their opinion and that at no stage was a census asked for or expected. The maps that follow are the result of these personal opinions, and for this reason are open to some question, but so long as this is borne in mind it is felt that they will prove of considerable interest and value.
This first series of maps is intended as something in the nature of an interim report. It is my hope that they, together with the complete table of results published in West Midland Bird Report No.16, will act as a stimulus to the further study of this problem. Errors of judgement there are bound to be, but I hope that every opportunity will be taken during 1951 to correct and improve on the picture we have been able to draw so far. Corrections based on reasonable evidence will be most welcome.
When there has been an opportunity for revision I hope to print additional maps and to follow these up with a parallel series to illustrate environmental factors likely to effect distribution.
A full list of acknowledgements, together with a list of Parishes included in each district will appear with the complete table in the West Midland Bird Report.
C. A. NORRIS.
January,1951.
[address removed]
Clent,
Worcestershire.