0000000001329964
AUTHOR
Raisa Tiilikainen
WEASELS’ (MUSTELA NIVALIS NIVALIS) PREFERENCE FOR OLFACTORY CUES OF THE VOLE (CLETHRIONOMYS GLAREOLUS)
Many studies on life history strategies of small mammals under predation risk are based on assumptions that mammalian predators use scent marking from prey in searching and hunting. This is especially true for small mustelids hunting in the tunnels and cavities of their prey. It is assumed that weasels use the estrous signs of female voles as hunting cues, which exposes such females to a more pronounced risk of predation. We studied the preferences of 57 least weasels (Mustela nivalis nivalis) toward odor cues from four different reproductive categories of the bank vole (Clethrionomys glareolus). In the first experiment, weasels selected clearly for vole odors over clean bedding in a Y-maze…
Complementary methods assessing short and long-term prey of a marine top predator ‒ Application to the grey seal-fishery conflict in the Baltic Sea.
The growing grey seal (Halichoerus grypus) population in the Baltic Sea has created conflicts with local fisheries, comparable to similar emerging problems worldwide. Adequate information on the foraging habits is a requirement for responsible management of the seal population. We investigated the applicability of available dietary assessment methods by comparing morphological analysis and DNA metabarcoding of gut contents (short-term diet; n = 129/125 seals, respectively), and tissue chemical markers i.e. fatty acid (FA) profiles of blubber and stable isotopes (SIs) of liver and muscle (mid- or long-term diet; n = 108 seals for the FA and SI markers). The methods provided complementary inf…
Project LIFE Saimaa Seal - Safeguarding the Saimaa ringed seal
The Saimaa ringed seal (Pusa hispida saimensis) is one of the most endangered and rarest seals in the world. The current population size is ca. 370 individuals, and the Saimaa seal is the only endemic mammal in Finland. The national conservation strategy and action plan for the Saimaa ringed seal was adopted in 2011 to improve the conservation status of the species. Even though the previous conservation efforts have been successful the seal still is endangered. The current seal population might overcome detrimental effects of a singular threat, but the combined effects of different threats may still be fatal to the population. The ongoing project LIFE Saimaa seal (duration 2013-2018) was ta…
Fishing restrictions is the essential protection method of the Saimaa ringed seal
The Saimaa ringed seal (Pusa hispida saimensis) is an endemic relict of the last ice age that inhabits a fragmented freshwater Lake Saimaa in Finland. This small seal population (current population size ca. 370-380 individuals) is one of the most endangered seals in the world. The high mortality rate of young seals due to by-catch mortality of fishing and insufficient snow conditions during breeding season are the most serious threats to the population. The fishing restrictions are the main short-term conservation measures of the Saimaa ringed seal. Springtime fishing restrictions have been set to reduce by-catch mortality of weaned pups. Certain fishing methods which can kill also adult se…
Improving the accuracy of estimations on natality and pre-weaning pup mortality of the endangered Saimaa ringed seal
The Saimaa ringed seal (Phoca hispida saimensis) is the only endemic mammal in Finland. It inhabits fresh water Lake Saimaa, and its population size is around 370 individuals with 60-80 pups born annually. One of the most critical threats for the population is climate change. The ringed seal is dependent on sufficient ice and snow cover for a breeding habitat, and mild winters have a negative effect on pup survival. In addition, the reliability of the population estimates, which are based on annual lair censuses, suffers when there is no sufficient snow cover for subnivean lairs or when the lairs are not detectable during the census due to early melting. For improving the seal stock monitor…