The relationship between the reindeer (Rangifer tarandus tarandus) and the ectoparasitic deer ked (Lipoptena cervi): reindeer welfare aspects

Thesis event information

Date and time of the thesis defence

Place of the thesis defence

Remote connection, Zoom link:

Topic of the dissertation

The relationship between the reindeer (Rangifer tarandus tarandus) and the ectoparasitic deer ked (Lipoptena cervi): reindeer welfare aspects

Doctoral candidate

Master of Science Sanna-Mari Kynkäänniemi

Faculty and unit

University of Oulu Graduate School, Faculty of Science, Ecology and Genetics Research Unit

Subject of study

Animal ecology


Professor Antti Sukura, University of Helsinki


Professor Seppo Saarela, University of Oulu

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The deer keds have impact on reindeer welfare

Possible impacts of the deer ked infestation on reindeer welfare and general relationship between the new host and ectoparasite were studied in this dissertation. Due to the invasion of the deer ked the period when reindeer are exposed to harassing insects has been prolonged in the southern part of the reindeer herding area. Material to this thesis was collected by experimental infestation, field observations and questionnaire survey.

The deer ked has clear impact on reindeer welfare. The deer keds which intruded to the pelt of the reindeer caused irritation. Reindeer scratched themselves with foot, mouth and antlers and shook their pelts. This action damaged the pelts of the reindeer and associated higher maximum surface temperatures were observed with infrared camera. Deer ked infestation can thus cause heat leaking spots to the pelts of the reindeer.

According to the field observations and questionnaire survey the deer ked can use reindeer as a host animal and reproduce on reindeer over winter until March. The hatching rate of deer keds was lower from pupae found from reindeer than from moose bedding sites.

Questionnaire survey revealed that deer keds are harassing reindeer on areas of 14 reindeer herding cooperatives and that here is local variation in the harassing frequency. Moreover, commonly used antiparasitic treatment with ivermectin, is effective against the deer ked.

In the future, it is important to follow the relationship between the reindeer and the deer ked and study deer ked’s reproduction and adaptation on reindeer and distribution of the deer ked in Fennoscandia. This information is needed to evaluate the general welfare of reindeer and other cervid species.
Last updated: 1.3.2023