Honlig reproduktionsfysiologi hos lodjur (Lynx lynx)

Abstract: Knowledge in reproduction in the Swedish lynx (Lynx lynx) is important forseveral reasons. Situated on top of the food chain, lynxes may be at risk of beingexposed to environmental toxins that could have adverse effect on reproduction.The population of lynxes is today managed by restricted hunting which demandsknowledge about both the lynxes numbers and their reproduction. In addition,lynxes may function as indicators of climate change for instance if their season ofheat would be earlier or prolonged due to a warmer climate. Today’s knowledgein reproduction in Swedish lynx is mainly based on information gathered fromradio collared animals. The Swedish National Veterinary Institute (SVA) gatherreproduction organs from lynxes on regular basis, both from hunted animals andfrom animals found dead. In earlier studies, the method of placental scar countinghas been used to estimate pregnancy rate and litter size. Lynxes differ from otherfelids as their corpora lutea remains in their ovaries for a long time, maybe severalyears. In earlier studies classification and counting of corpora lutea and Graafianfollicles has been done to estimate ovulation frequency. This work, whichincludes reproductive tracts from 32 female lynxes, aimed to evaluate whichmethods would be appropriate to use when evaluating reproductive tracts inlynxes. In addition, basic data were gathered for continuing environmentalmonitoring and assessment. When counting placental scars pregnancy rate was 72percent. The number of placental scars ranged from 1-4 and were on average 2,24+ - 0,70. This data accords with previous data on pregnancy rate and litter size ofthe lynxes. Corpora lutea remains in the ovaries for more than a year making ithard to properly count the corpora lutea due to difficulties to determine how oldthey are. When determining stage of the oestrous cycle it is useful to considerseveral parameters. Two lynxes had paraovarian ectopic adrenal tissue in theovarian ligament, to the author’s knowledge not previously described in the lynx.