The Annual Spring Otter Survey
2020 Results Summary
Despite the Covid-19 pandemic, and the resulting lockdown regulations that have been in place since late March, the eighth Annual Spring Otter Survey took place over the weekend of the 25th/26th April 2020.
It must be said however that this was a slimmed down survey with many volunteer surveyors unable to access all or part of their survey patches or being in isolation and therefore not able to take part at all. The decision to go ahead was taken after much thought and consideration. Most of the training sessions had already taken place by the time lockdown came into effect and all participants were advised that they should only survey within their local area and to do so on foot. As a result, coverage was much patchier than usual and there were some areas that were barely surveyed at all.
Over the weekend 84 volunteers, or teams of volunteers, managed to survey 85 patches containing 456 sites. Of the 456 sites checked 259 (57%) were positive for otter signs – this is a considerably higher percentage than usual and may be due to surveyors reducing the number of sites checked and concentrating on those that are known spraint sites. A further 11 sites had possible but inconclusive signs. There were 186 sites (41%) which were totally negative – this is obviously lower than in previous years in line with the above.
There were 48 Day 2 ‘hits’ (fresh signs) and as usual, many of these ‘hits’ were located close together in the same or neighbouring patches and so have been adjudicated as belonging to a single territory.
We would like to thank ERIC North East for their support of this year's survey from their Small Grants Fund
The full survey report can be accessed via the link at the bottom of this page.
2019 Results Summary
The seventh Annual Spring Otter Survey took place over the weekend of the 27th/28th April 2019 and once again thanks and congratulations are extended to all the volunteers who took part. Tees Valley Wildlife Trust volunteers also took part again allowing us to continue to monitor the otter population in the Tees Valley.
The Otter Survey bounced back this year with a new expanded area and more volunteers and survey patches than ever before. A total of 123 patches of watercourse were surveyed on both days containing 681 sites. Of those 681 sites 281 (41%) were positive for otter signs. A further 18 sites had possible or inconclusive signs. There were 382 sites (56%) which were totally negative. This continues to give us confidence that we are looking in enough places as there are still more sites where there are no otters than sites where we find evidence of otter activity. It is unlikely therefore that we are overlooking many.
There were 82 Day 2 ‘hits’ (fresh signs) which is the highest yet but not surprising given the larger area covered and increased number of volunteers. As usual, many of these ‘hits’ were close together in the same or neighbouring patches and so have been adjudicated to belong to a single territory. The total number of adjudicated territories this year is 47 - again it must be emphasised that this is for a larger survey area. If the territories that were identified in the new areas are taken out then the equivalent number of territories for the previous survey area is 40. This is still an increase and a very positive result.
For those unfamiliar with the way the data are analysed it is important to emphasise that we are counting otter territories here not individual animals. It is reasonable to assume therefore that at least some of the adjudicated territories will contain females with cubs meaning the number of actual otters will be greater than the number of territories. However, this really is the only way of getting any kind of numerical data when surveying for otters which are an elusive, wide-ranging, cryptic animal with no individually identifiable markings.
Full Survey Results
Please click on the links below for full annual survey reports.
Results of the 2015 Durham Wildlife Trust Otter Survey