Where are the shags that roost in Slovenian sea during the day?
The Mediterranean Shags that roost at the communal roosts near Debeli rtič, Strunjan and Sečovlje disperse across the sea during the day. We have no data, with exception of some random resightings of ringed birds, where precisely are they roaming and foraging. GPS telemetry devices which we will put on about 40 Mediterranean Shags, will send us data about their daily movements at Slovenian sea and broader.
Why tracking individuals?
Telemetry of wild animals has been lately progressively used in ecological research in which data on locations and movements of otherwise hardly trackable animals are of crucial importance. In our project the distribution of Mediterranean Shags at the population level will be mapped on bases of monitoring at sea by boat, but this method solely does not meet the criteria for identifying marine IBAs. According to the standardised techniques at least two methodologically different set of species spatial data are needed to properly identify the marine IBA.
GPS telemetry devices
The telemetry devices which are being mounted on wild animals differ in several aspects: the method of … locations, the way of transmission of the data to the user, energy source, size, weight and shape, and the method of mounting on an animal. In the telemetry reasearch in the project SIMARINE-NATURA we use tracking devices of Polish producer ECOTONE (model DUCK-3). These GPS loggers enable transmission of the data by GSM network. The devices are supplied with energy through solar panels, which can provide enough energy in good light conditions to fix GPS position every half an hour. The data is transfered to server by sms where they are directly accessible to the user. The user can change settings like the frequency of fixing GPS data and daily hours of device activity remotely. The device is mounted on birds permanently as a backpack with straps of teflon ribbon.
The main reasons to use this kind of telemetry devices on Mediterranean Shags in our project are: sufficient frequency of GPS position fixes, extended period (several weeks) of activity due to solar source of energy, and remote data download. Especially the latter characteristic is crucial to track the Mediterranean Shags in their non-breeding areas, where recapture of the individual with the tracking device is practically impossible.