Wildlife management in times of climate change: Studies on thermoregulation in wild boar
It is now undisputed that we are in a phase of climate change. According to current knowledge, so-called greenhouse gases cause a steady increase of global annual average temperatures. In our moderate latitudes this means that the winters become milder and the summers hotter, combined with more extreme weather events such as thunderstorms and storms. But how do wild animals react to this climate change and the associated changes in their environment? Very little is currently known about this question. Initial studies have shown that some animal species shift their range; in others, climate effects on reproduction or survival probability have been observed.
Within the framework of a Europe-wide study on the population development of the wild boar (Sus scrofa) conducted at our research institute, strong climate effects have been identified. It has been shown that milder winters are increasingly contributing significantly to the growth of the population of European wild boar populations. It is expected that this trend will continue. But is the prognosis of a further rise in popularity correct in the long term? To answer this complex contextual question, we need to better understand the physiological basis of temperature regulation and its impact on the energy budget, and thus on essential characteristics of the life cycle strategy (e.g., reproduction and survival).
The special physiology of the wild boar makes it a very exciting research subject in this context. In contrast to many other mammals, an important mechanism of cold tolerance is lacking in wild boars: the creation of heat without shivering in brown adipose tissue. For this reason, wild boar like warm temperatures and mortality rates rise sharply in cold winters, especially among piglets. However, wild boars also suffer in hot and dry conditions because they have very few sweat glands and cannot cool their bodies by sweating. The typical mud-wallowing of pigs is actually a behavioral adaptation that cools and protects against overheating. It is already apparent today that there is a strong positive correlation between presence of water and presence of wild boar. One should therefore also bear in mind that forecasts for population dynamics suggest that the hot and dry summers, which are increasingly likely in our latitudes, could cause problems for these animals. In fact, the above-mentioned study also showed that hot summers can have a negative impact on the growth of wild boar populations.
In order to better understand these contexts, we are currently carrying out a research project at the Research Institute of Wildlife Ecology of the Vetmeduni Vienna. The following aspects and questions will be investigated in detail:
A) Influence on body temperature and energy consumption: By means of implanted temperature loggers (subcutaneous and in the body core) we are investigating how the body temperature of wild boars changes throughout the annual cycle. We are also analyzing how extreme heat periods or cold spells affect body temperature. Using implanted heart rate loggers we will investigate the influence of climatic conditions on the metabolic rate. We will also record the effect of the energy budget on survival and reproduction.
B) Behavioral adaptations and activity patterns under different climatic conditions: Through a modern system of continuous animal tracking, we want to capture the climate influences on the wild boars´ daily activity pattern (spatial, temporal and intensity). How active are the animals during different seasons, when and how often are they looking for e.g. water and food? Do rest phases also change under different climatic conditions? Behavioral observations are supporting our analyses. Our records include the temporal framework of reproductive activites as well as the social structure.
C) Consequences for the management of wild boars: As a long-term goal, we plan to use the results obtained from this basic research to inform the development of management strategies. An effective management of wildlife such as wild boar, which are often in conflict with human economic activities, is extremely important and of great economic interest. The results of our study could, in addition to important and new findings in basic research, contribute in the long term to 1) forecasting population developments in global climate change, and 2) developing targeted management plans adapted to the changing climate situation.
Project duration 2016-2019