Porównanie trzech metod szacowania liczebności kopytnych na przykładzie Roztoczańskiego Parku Narodowego

Autorzy

• Zbigniew Borowski Instytut Badawczy Leśnictwa Zakład Łowiectwa ul. Bitwy Warszawskiej 1920 r. nr 3 00-973 Warszawa
  e-mail: Z.Borowski@ibles.waw.pl
• Jakub Borkowski Uniwersytet Warmińsko-Mazurski w Olsztynie, Wydział Kształtowania Środowiska i Rolnictwa, Katedra Leśnictwa i Ekologii Lasu, Pl. Łódzki 2, 10-727 Olsztyn;
• Przemysław Stachyra Roztoczański Park Narodowy

Abstrakt

Ungulates, primarily cervids, are keystone species as they play a crucial role in the forest ecosystem functioning. In commercial forests, hunting is the most intuitive and straightforward solution to regulate ungulate population density; managing large herbivores in protected areas is much more complicated. On the one hand, deer pressure on vegetation is a part of the natural processes shaping these ecosystems. On the other hand, however, when at high densities, deer can alter natural plant succession trajectories and generate conflicts in nature conservation. Nevertheless, information on population density or trends of these mammals is necessary to predict the potential role of ungulates in forest ecosystems and manage herbivore population densities. Unfortunately, most often, the managers of protected areas do not know the current population status of the large mammals living there. Furthermore, it could be impossible to analyse the large herbivore population trends based on historical inventory data collected using different methods with unknown accuracy. Here we discuss the advantages and disadvantages of three most commonly used inventory methods for large mammals in Poland, such as snow tracking, driving censuses, and pellet group counting. Conclusions on the reliability of the three methods were drawn based on the results of ungulate inventories in the Roztocze National Park, Poland. Snow tracking generates an error of unknown magnitude; therefore, historical data estimated by this method should be cautiously approached. Additionally, with this method, only coefficients are obtained, based on which it is impossible to estimate the population size. The pellet group counting is the least variable method regarding errors; it is cheap and logistically straightforward. Moreover, it also allows the analysis of winter habitat preferences of ungulates. It is therefore recommended as a method for estimating deer and wild boar abundance in many countries worldwide. In summary, long-term trends in abundance are most important for analysing and managing large mammal populations. Therefore, it is necessary to carry out inventories over several years, for which, due to the minor estimation errors and simple logistics, the pellet group counting method seems best.

Słowa kluczowe

• jeleń szlachetny
• sarna
• dzik
• oszacowanie zagęszczeń
• wild boar
• density estimation
• kopytne
• Roe deer
• red deer
• ungulates