IUCN Otter Specialist Group . . . leading global otter conservation Last Update: Tuesday August 9, 2011
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Conservation Genetics of the Eurasian Otter in Sweden


In this thesis, molecular genetic methods were used to study a threatened species, the Eurasian otter.  Estimates of population size and population dynamics parameters were obtained, the genetic effects of a restocking program was evaluated, and a population viability analysis was conducted to assess which demographic parameters are the most important for the future viability of an otter population.  Many of the studies were based on non-invasive genetic sampling of faeces.

In the genetic evaluation of the restocking program, it was found that the released otters had contributed to subsequent generations.  However, the effects were to a large degree limited to the near surroundings of the release areas.

Comparison of two census methods, snow-tracking and non-invasive genetic census based on faeces, showed that approximately only half of the otters detected with the genetic census were found with the snow-tracking census.  It is recommended to combine these two methods to obtain the most reliable estimates of population size.

A short-term study on population dynamics is otters showed that apparent survival was higher in females than in males and that the rate of addition was also high and likely influenced by migration.

The population viability analysis incorporated both genetics and demography and revealed that survival to first reproduction was the most crucial demographic parameter affecting the viability of the study population.  This result suggests that conservation efforts should be focused on protocols that enhance the survival prospects of young females.  Environmental stochasticity was also found toe have large effects on the probability of extinction of this population.

For full text, see link: http://www.diva-portal.org/diva/getDocument?urn_nbn_se_uu_diva-7633__fulltext.pdf


Johanna Arrendal
Dept of Animal Ecology, EBC
Uppsala University
Norbyv 18d
SE-752 36 Uppsala
Phone: +46-18-471 29 30
E-mail: Johanna.Arrendal@ebc.uu.se