A female aged 5-6 years and weighing 28 kg was captured and collared near the Šija hill in Gorski Kotar on 17 September 2004. She was named W10-Tanja and she was the reproductive female (alpha-female) of the Risnjak pack. It was established that Hilda and Blaža were her offspring, while young male Felix was her grandson.

Since summer 2004, the Risnjak pack was monitored via the female Tanja. Tanja moved into new areas, such as the area around the Kupa spring, the Kupica Canyon near Delnica, and it is very interesting that she was also on the south side of the motorway, at the Sopač hill. This means that the Risnjak pack had succeeded in finding passage over the motorway. With this, the pack territory was enlarged to 193 km².

At the end of August 2006, Tanja's signal was lost. Her fate became known on 8 October 2008, more than two years after her disappearance. A member of the Lovke hunting society, Miroslav Šafar informed Dr. Kusak that a walker had found the collar at the bottom of the Lokve Lake during a period of very low water levels. The collar was about 30 m from the shore, and it did not emit a VHF signal, but it was not destroyed. More precisely, the collar had not been cut, instead it was still attached with the original screws. The find of the collar suggests that Tanja was likely killed by a poacher at another site, and her head was cut off and the collar removed and thrown into the lake. The VHF signal could not be detected at the bottom of the 20 m water column, though the collar was still functional.