Summer 2002 No. 13

Page 2

RESULTS
SUMMER 2001-WINTER 2002

Overall, the annual average is up again to 26.7 % of all sites checked being positive (last year it was 16.14%). This is based on a smaller sample than last year as the Spring survey could not happen due to the Foot and Mouth outbreak. Most individual river catchments also have an increase in the amount of positive spot check sites. The exceptions to these are the River Piddle (48.32% of sites were positive) and the River Wey and Fleet which had one positive record last year for Radipole Lake.

Although otter densities continue to increase on rivers where they are present, they still have not become established on the Wey and Fleet and on Poole Harbour. Both areas have had odd records, an otter was seen on Radipole lake last year, one was on Brownsea two years ago but not now. Open water areas such as the Fleet and Poole Harbour are very difficult to survey and it is possible that we could be missing more signs. However freshwater streams which otters would need to access in order to drink and maintain their coats should be good places to look if they are there.

On Poole Harbour good places to also look is the mouth of the Frome, Piddle, Corfe and Sherford Rivers as well as the Studland Streams. Other possibilities (but quite hard to survey) would be the wetlands and lakes on Brownsea, Littlesea and reedbed areas (very difficult to survey). However in all these areas only the Lower Piddle gave any positive records last year, but there is no indication that any otters are leaving the Piddle and going onto Poole Harbour. It is interesting to note that there are no such records for the Lower Frome, despite regular checking of sites by members of the Dorset Otter Group. The Rivers Corfe and Sherford would benefit from a more sustained checking effort, but wardens on Brownsea always keep a look out for otter signs.

NEW POOLE HARBOUR CO-ORDINATOR

John Lamming has retired from the role of Poole Harbour co-ordinator but is thankfully staying on as a surveyor. The new Poole Harbour Co-ordinator will be Graham and Sue Windsor, so send your area results to :

7 Egdon Glen, Crossways, Dorchester, Dorset DT2 8BQ. Tel. 01305 852569

WINTER 2001 RESULTS

REMEMBER The Spring Survey Results are due in at the end of May. The Summer survey starts on the 1st June and continues to the 31st July. Results are then due in at the end of August.

Figures continue to increase! Last year the winter survey result was 18.8 % of checked sites were positive. This year it is 24.8% (although this is not as high as last quarter’s record result of 31.7%).

WANTED – New Homes for Otters

With all these talks and walks going on for Dorset Otter Group, as well as a couple of generous donations I have accumulated a pot of money which can go on making otter holts. What I do need is sites where they can be built so if any of you own land along the river or know of any landowners who would allow an artificial holt to be built on their land let me know.

There are two types of artificial otter holt that can be built. A log pile holt and a pipe and chamber holt. A log pile holt is considered more ‘natural’ as it is built from a tree with logs forming the surrounding walls and interior chambers, with branches placed on top to form the roof and the twiggy brash on top of this as a kind of ‘thatch’. Lots of other species can exist in this habitat too as it is effectively a dead wood pile which usually gets covered in bramble and ivy, making it more secure (ie. Not carried away with a flood) and water-tight.

A pipe and chamber holt is more artificial but usually lasts longer. It is made out of breeze blocks and paving slabs which are buried underground with plastic drainage pipes leading out to the water. Scrub species can be planted on top of the holt to provide further cover for the otter or otters if a mother and cubs set up home.

I am working on information sheets on otter holts and other habitat enhancements for otters at the moment. These will be available from Dorset Wildlife Trust or directly from the Dorset Otter Group Website.

Bronwen Bruce.