Flying squirrels have survived equally well on identified and marked protection sites near fellings and in areas were no felling has been done, a study reveals.
Ms. Tiina Hynynen, Master of Science, wrote her master’s thesis on the breeding sites and resting places of the Siberian Flying Squirrel which the Regional Environment Centre of Central Finland had identified and marked within its area in 2004–2007. According to her study, flying squirrels had survived equally well in these marked-out areas and in control areas where no fellings had been carried out.
In practice, sighting a flying squirrel means a sighting of the squirrel’s droppings. If droppings are found, one can assume that the area is actively used by a squirrel.
The Flying Squirrel itself is seldom seen as it mainly moves about at dusk. Hynynen did not see a single one during her research.
During 2004–2007, the Regional Environment Centre of Central Finland identified and marked 29 breeding sites and resting places outside felling sites. Hynynen researched these and the control areas during the spring of 2009.
”At the time, there were no droppings on three of the sites. The situation was the same on the control areas. I found no droppings on four of them.”
Results differ from previous study
Both the breeding sites and resting places as well as the control areas had plenty of timber, on average 300 cubic metres per hectare. The share of deciduous tree species varied between 0–70 percent.
Previous to this, only one study similar to Hynynen’s has been carried out in Finland. The results of the previous study, done in the western parts of the country, were the opposite: the marked-out areas were not sufficient to maintain the Flying Squirrel population.
Hynynen says that the most evident difference between the marked-out areas in the two regions is their size. In Central Finland the average size of the marked-out areas is 35 ares, while in Western Finland the average was 18 ares.
The study offers no clear answer as to why Central Finland has succeeded in the identification and marking of the breeding sites and resting places. The average size is not necessarily the answer, for one single marking-out decision can concern several separate areas.
An obviously important factor was the location of the marked-out areas in relation to surrounding forests: even though a felling had been carried out next to a marked-out breeding site and resting place studied by Hynynen, the connection to other forests remained. There was only one exception.
”There was only one marked-out area where the nearest forest area was 50 metres away, on all others it was closer. None of the marked-out areas was an island in the middle of a clear-felling site,” Hynynen says.
Unexpected corridors of bush and forest
Using aerial photographs, Hynynen analysed the forest cover within 200 metres of the marked-out and control areas. She also analysed the squirrels’ opportunities for movement on 160 hectares surrounding these areas.
Hynynen says that she was surprised by how many connections there were between the forest areas. The aerial photos revealed that forests and bushes formed an unexpected number of corridors/links/linking corridors among buildings and fields.
”Driving around on the larger roads I had thought there was nothing but fields with only occasional forest areas.”
Protection policy changed in 2004
There are few studies concerning the success of protecting the Flying Squirrels near felling areas. This is partly explained by the conservation history of the species.
As a species, the Siberian Flying Squirrel has been protected in Finland since 1924. Since 1997, also the breeding sites and resting places of the squirrel have had to be conserved, at first only if they differed significantly from the surrounding natural environment.
As of 2004, the requirement for a significant difference was removed, and all breeding sites and resting places in active use had to be conserved from felling and other land use.
Only one study has been made of the size of the Finnish Flying Squirrel population, dating from 2006. According to the study, there are 143,000 female Siberian Flying Squirrels in Finland, and as many males.
Notification of forest use launches the process
In Finland, the breeding sites and resting places which must be protected during fellings are identified and marked when a felling is planned for an area. The Forestry Act requires that the forest owner must notify the Regional Forestry Centre about a felling at least two weeks before it starts.
On receiving the notification, the Forestry Centre checks whether there are known Flying Squirrel breeding sites or resting places in the area. If so, the Forestry Centre notifies the Environment Centre about the felling, as well as notifying the forest owner and the company buying the timber and performing the felling about the presence of squirrels.
The Environment Centre checks whether the breeding site or resting place is in use and if so, marks out the areas which must be protected from fellings.
Tiinan Hynynen's research was funded by the Metsämiesten Säätiö Foundation.
By Krista Kimmo
 Finnish flying squirrel population thrice the size assumed
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