The Otter Network 2019 Spring Otter Survey
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.
The full report is available as a pdf on the Links and Downloads page.
The 2020 survey will be again be an Otter Network event and will take place over the weekend of 25th/26th April. If anyone reading this would like to take part please contact Vivien through the Contact page of the website.
We also try to answer new questions using a mixture of old and new survey techniques.
2014 concentrated on mortality on roads in and around Newcastle and if such mortality could be explained.