The Yorkshire Flat Hedgehog Survey: Is Yorkshire 'bristling' with Hedgehogs, or are they getting 'thin on the ground'?
Introduction - During 1990 and 1991 the Yorkshire Naturalists' Union and its affiliated societies undertook a survey of Hedgehogs throughout Yorkshire. The results were quite a revelation.
The prickly subject - Although this is one of the best recorded Yorkshire mammals with most of the records coming from road casulaties, the number and distributionof records tended to reflect the concentrations and enthusiasm of recorders. Dr Pat Morris of the Mammal Society devised a standardised transect in which car passengers recorded Hedgehog road casualties from July to September in measured transects. There were at least 20 miles on A, B or C roads in daylight in dry conditions (the transects were not repeated in less than 30 days). Expressing the results as Hedgehogs per 100 miles, this showed pronounced regional differences with fewer in the south-west and greatest numbers in the north-east.
The prickly results - In the 1990-91 survey Yorkshire naturalists undertook 145 transect journeys of at least 20 miles, travelling 4,915 miles and encountering 342 Hedgehog casualties. They gave a mean density of 6.9 Hedgehogs per 100 miles.
Regional differences - Splitting Yorkshire into distinct geographical regions showed smaller numbers in the south and west (0.6 in the Southern Pennines, 3.8 in lowland South Yorkshire), larger numbers in central areas (10.8 in the Vale of York) and the greatest numbers in the east (12.58 on the Wolds).
The deadly school holidays - By only surveying through the mid-summer period when Hedgehogs are most numerous and most active, major seasonal differences are avoided. However, within this three month period, peaks in casualty rates coicided with the a) the commencement of school holidays, b) a fortnight later in the mid-holiday turnover and then c) the August Bank Holiday weekend. All these events generate nocturnal journeys by people travelling to and from holiday venues.
Monitoring the changes - Recently, various national surveys have indicated a catastrophic crash in Hedgehog numbers to the extent that the Hedgehog is categorised under the NERC Act 2006 as a 'Species of Principal Importance' for biodiversity ... So 20+ years on, let's repeat the Yorkshire survey and look at the changes in Hedgehog populations within the Yorkshire landscapes ... Are Hedgehog road casualties getting thinner on the ground?
Please download the survey form and accompanying instructions below and join in. For any queries please contact Colin Howes in the first instance by clicking here (opens email)
WARNING: For reasons of safety, this project is for passengers only and not for drivers.
Flat Hedgehog Survey Documents
Flat Hedgehog Survey Instructions can be opened/downloaded by clicking here
Flat Hedgehog Survey Recording Sheet can be opened/downloaded by clicking here
The Yorkshire & Humber National Character Map can be opened/downloaded by clicking here