Release of the water voles!
August 19, 2009 § 4 Comments
This week, RZSS was in Aberfoyle, helping with the reintroduction of two hundred native water voles, as part of our native species conservation work.
This was the second stage in three year water vole project, for which RZSS is a partner, along with Forestry Commission Scotland, Loch Lomond and Trossachs National Park, Scottish Natural Heritage, Derek Gow Associates and Kilgarth Development Company.
Water vole previously inhabited this area of Scotland, but had gone extinct as a result of habitat disturbance and the presence of the introduced American mink (a predator species). Following the re-establishment of wetland sites and the control of American mink by the Forestry Commission, the Trossachs Water Vole Reintroduction Trial was set up to repopulate the area with water vole, and to monitor their success over the three years.
The project began last year, when over five hundred water voles were released into wetland sites in Loch Ard Forest. Post-release monitoring of the animals showed that they survived their first ‘wild’ winter, and went on to breed and disperse.
Monitoring the voles is very high-tech; once they have been caught they are weighed in a ‘Pringles’ tube!
Just this week the population was topped up with another two hundred water voles, released at sites, which the other water voles were unlikely to naturally disperse to. The soft release (release into acclimatisation pens at the release site) of these animals went well and they will be fully released towards the end of this week.
The voles are transferred from their traveling crates to their ‘acclimatisation pens’
Monitoring will then continue throughout the year, to assess how well the water voles are doing. The monitoring will also help assess the need for a further release next year, to help ensure the genetic health of the population. As a partner in this project, RZSS has helped to fund the purchase of tags for the release animals and the keeping and breeding of these animals prior to release. We have also provided assistance in the release and monitoring of the water voles, as well as providing interpretation for the project.
If you are in the Aberfoyle area, you are unlikely to see any of these elusive little rodents. However, there are plenty of field signs to look out for, as well as a whole host of other wildlife (we spotted Ospreys and Common Lizards on our last visit)!
The pens are then carried to a typical release site
It’s not just the water voles that have been getting special attention this week. The penguins have had some special care too! This week SCUBA divers from the Forth Valley Sub-Aqua Club came in to clean the penguin pool. This happens a few times a year and is done to clean the algae that builds up on the inside of the underwater viewing windows and on the spy ball camera. The algae builds up naturally over the year, and diving down to it, is the only way to clean it. The divers will also sometimes put in fake seaweed or move a few rocks around, to ensure the underwater habitat of the penguins is just right! The divers are all volunteers and give their time to have some diving practice and the unique opportunity to swim with penguins. Sounds like a lot of fun to us, but probably very smelly as well!
One diver gets to know the penguins!
You may recall that we welcomed two new female drill monkeys to Edinburgh Zoo a little while ago. They can be seen in the monkey house. These new individuals were originally kept separate from the drills already resident in our collection in order to give them time to settle into their new surroundings, and to enable them to undergo a compulsory 6 month quarantine period.
However, the primate keepers have now decided to begin introducing the new drills to the rest of the group. As with many other zoo animals, introductions can be lengthy, and unfamiliar individuals can not be simply thrown together! Primates in particular have complex social systems, and can become very aggressive to one another if they feel that this is threatened. Therefore, the new drill monkeys are currently being introduced to the resident group for short intervals (up to an hour maximum) at a time. During these sessions, keepers will keep a close eye on the drills to observe how they react to one another, and to intervene to prevent any aggression if necessary. These introductions happen as often as possible (every day usually) and keepers will gradually increase the length of time that the drills spend together, as they get more used to one another.
So far, the introductions have gone well, with limited aggression. The two new females have apparently tried to ‘pick on’ our resident female a little. However, the two males have been reportedly sticking up for her and protecting her! This kind of interaction is to be expected as primates get to know each other and determine their social standing in the group.
And, the two new females have also been spotted ‘presenting’ to the males, which is very promising in terms of future breeding prospects for the group! Presenting involves a female turning away and offering her rear in a submissive manner. This indicates that she would like to copulate with that male! With any luck, once these endangered primates have been permanently introduced to one another, they will begin breeding. We will keep you up to date on their progress right here!
The rear end of the baboon-like drill monkeys is crucial in communication!
Finally, we waved goodbye to the Cotton top tamarin monkeys this week. The cotton top tamarins have been residents in the Magic Forest for many years, and were easily recognizable by their very funky hair dos and inquisitive behaviour! They bred well at Edinburgh, and their group size grew quickly. As often happens with breeding collections, many of the individuals were moved to other zoological collections to prevent inbreeding and overcrowding. This year, it was decided that the cotton top tamarins would leave the Edinburgh Zoo collection entirely to make room for other, higher priority, primate species. The final group left last week for South Lakes Wild Animal Park, and we are sure that they will enjoy their new home. We will keep you up to date with the new species arriving at the zoo in the future.
Farwell to our furry little friends!
Tagged: Aberfoyle, aggression, breed, clean, conservation, Cotton Top Tamarins, Drill, edinburgh zoo, introduction, leaving, mixing, monitoring, native, penguin, presenting, primate, reintroductio, release, Royal Zoological Society of scotland, SCUBA, social, species, Trossachs Water Vole Rentroduction Trial, water vole