중동부유럽

Roe deer (Capreolus capreolus L.) are a common species in Central Europe. In the 21st century, it was discovered that roe deer in Poland have fewer fawns than in the past. Therefore, their fertility was investigated. It turned out that most of the females had a chance of having twins. However, in summer 2015, 60% of females did not participate in mating, and those that did had the chance of having only one fawn. In this unfavorable year, the roe deer experienced an alternative estrus in late autumn. As a result, the decrease in the number of fawns was not very large. We have described the consequences of the late autumn estrus, which had been reported in the past but not confirmed in scientific studies. In 2016, almost 100% of the females studied mated again in the summer. We assume that the reason for the low mating activity of the roe deer in summer 2015 was heat stress, which limited the normal function of their bodies. This summer was exceptionally hot with days above 30 °C, which coincided exactly with the summer mating season of roe deer. The high temperatures were accompanied by low rainfall, leading to extreme drought and reduced food availability. Global warming may impact the reproduction of roe deer and other animals, so it is worth considering climatic conditions in population research, and not just in terms of food availability.