This report updates all activities since the WMIL team, plus volunteers left Canna on 1st April 2006. Much of April was taken up with the production of the Interim Report which had to presented to the EU LIFE Nature team by 30th April 2006. This also involved collating all the financial expenditure on the project and presenting that in the format required by the EU Life Nature team. This was quite a big job and took up a lot of the project administrator and project manager’s time.
The management of the assurance population of Canna Woodmice has so far gone without incident since their capture and removal from Canna in October 2005. In the past 2 weeks the births of three litters have been recorded (2 at the Highland Wildlife Park and1 at Edinburgh Zoo) which suggests that either Canna wood mice naturally breed later than their mainland counterparts or an aspect of their captive management has delayed reproduction. Housing capacity at HWP is due to be expanded to accommodate some increase in the population but excessively high densities are likely to suppress breeding and/or reduce welfare.
Mouse monitoring work took place in mid-May, to try and determine the size of the surviving population. WMIL had recorded signs of mice at a number of bait stations during the monitoring stage of the project, the locations of which were forwarded to RZSS. In May specific monitoring for Apodemus was carried out by Fraser Dodds using 2 trapping grids of 25 traps (5x5) each, with initially 10m spacing increased to 25m spacing on some of the accessible sites indicated by WMIL plus those sites where initial capture had taken place. Additionally, hair-tubes were left in place for 10 days along major corridors such as dry stone walls. No Apodemus were caught in 10 nights of trapping (500 trap nights) and the hair tubes (baited with peanut butter) showed no sign of mouse presence. This exercise is to be repeated in early June to further determine the presence, and estimate the size of any remnant population of Apodemus. This information will be used by the Steering Group to assess whether or not a trial-reintroduction should take place later this summer.
A presentation on the mitigation programme was given at a Scientific Meeting at ZSL in early May.
One of the predicted results of eradication of rats is an increase in the rabbit population. Accordingly, Abbie Patterson set up some monitoring plots on Canna and Sanday to try to detect changes in rabbit numbers.
In late May the project administrator along with Highland Ringing Group members; David Aiton, Helen Chisholm, Ronnie Graham, Tony and Helen Mainwood visited the island and checked 850 bait stations for signs of rat presence. 749 of these stations were in the grid set up by WMIL, but an extra 101 stations were also covered. A decision was made not to check the stations in the seabird colonies at Geugasgor and Lamasgor as it would cause unnecessary disturbance to the birds that were just starting egg laying. Extra stations in these areas were covered instead. No rat signs were detected in any of the 850 stations checked. A few nibble marks were found on wax blocks in 17 of the stations but these were all presumed to be mice or shrews. Monitoring sites out with bait stations were also randomly checked (particularly at Iola Sgor) and although some were found with peck marks and nibbles, none were thought to have been as a result of rats.
Sixteen permanent rat trap boxes were set up around the new pier and along the approach roads, to try and trap any rat they may have come off a visiting ship. These will be checked on a regular basis.
The Highland Ringing Group team also made a start on the seabird monitoring work. As a result of the cold late spring many seabirds are laying much later than usual, so only preliminary figures are available at the moment. These suggest that the rapid decline in shag numbers, as a result of rat predation, may have been halted, particularly at Geugasgor. Further good news was the location of a breeding Manx Shearwater in a burrow above the Nunnery colony. Other shearwaters were heard above the former Tarbert Road colony, where hopefully a few pairs continue to nest on inaccessible ledges on the cliffs. Indeed, Chris Rodger and Clair Smith, using tape playback, located an occupied burrow there on 10th June, in the 'former' colony below the crags.
Copies of the project leaflet (also available on this web site) are now being widely distributed in various outlets in Mallaig, as well as on the island ferry, the MV Loch Nevis, and in all holiday homes and the tea room on Canna. These describe the project and explain how visitors to the island can assist with the project.
Bob Swann, Project administrator.
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