As it was already published that in Naliboki Forest during summer, autumn and early winter 2019 more than a half of the local population of lynxes died from unknown disease. According to the intensive camera-trapping by about 70 cameras as well as by regular checking of lynx tracks, in Naliboki Forest in the model area of about one thousand square km 7 out of 13 adult males (S’tsiapan, Ksavery, Maxim, Bazyl’, Kazimir, Jan, one without name) and one adult female Jadz’viha disappeared. 7 out of 12 adult females (Jaryna, Vieranika, Pryhazhunja, Maximiliana, Malanka, Pielahieja and Bazylikha) were registered without any kittens in autumn. Two of them definitely lost them. Other afive dult females had 1 or 2 kittens only.
In January-March 2020 the decline in lynx local population in Naliboki Forest continued. In February Vikienta and Kazimirchyk adult males got ill, but then they gradually recovered. It looked like they, being still weak, did not take part in the mating neither in the late February nor in March. Also, in early February Mikal and Symon adult males got ill and then disappeared. Also, Bazylikha adult female and four kittens a total disappeared in February.
Sick Vikienta in the late January.
So, in effect of the disease impact just before mating in the model area of Naliboki Forest there were 13 adult females and only two adult males in fit (Tsypruk and Jury), while Vikienta and Kazimirchyk were still too weak for mating. This disproportional situation in the sex-ratio could lead that many of the adult females get no pregnancy after the mating season. The only hope was that adult males would come into the area from somewhere else. Actually just this scenario took place. At least, three new adult males were documented to be present in the model are in Naliboki Forest in the late February-March. It is worthwhile to notice that one of the adult male appeared in the main area of still weak Vikienta, and the new one was documented walking with one of the adult female there.
Thus, when the local adult male lynxes mostly died in Naliboki Forest, mating in the local population of lynxes was mainly provided by immigrated adult males.