THE SUFFOLK OTTER SURVEY A Preliminary Report RODNEY B . W E S T a n d PETER NICHOLSON
THE European Otter (Lutra luträ) has for centuries lived and bred throughout East Anglia. Until quite recently it was thought that Suffolk and Norfolk were among the better populated areas in the country. The Otter's present status has been outlined in a report published by the Mammal Society of the British Isles (Mammal Soc., 1969). The findings, based on Otter Hunt returns, indicate that there has been a considerable decrease in the Otter population throughout the southern half of the country. One of the worst affected areas has been East Anglia, where a decrease of 5 -4% of the total Otter population was estimated for the period 1957-67. As a first assessment, the Mammal Society's report was a creditable one and its value really lies in showing how very little we know about this animal. For instance, just how many Otters are there in Suffolk and where are they? This note describes the first results of a field survey set up in July, 1969, to try and answer these questions. Methods There are well over 600 miles (900 km.) of open water and marshes in Suffolk. Obviously it would not be possible, or desirable, to survey every length of likely habitat and it was decided that a representative sample only would be taken. The survey started on Ist July, 1969, with an appeal for volunteers prepared to make regulär searches of a fixed length of river bank or marsh. By Ist February, 1970, fifty-two volunteers had agreed to help, covering approximately 40 miles (65 km.). At each visit, evidence for the presence of Otters was noted on a specially prepared report card. Weather, time, and duration of visit was also recorded. Cards were completed for all visits, including those made when no Otter signs were present. Results A total of 126 completed cards, representing 290 man-hours in the field, have been received covering the period Ist September, 1969 to Ist September, 1970. Thirty cards had a positive finding whilst a further ten were noted as "probables". The remaining returns were negative.