A new study has found that satellite images help to predict when bears will have little food in the forest – a moment when the risk of bear attacks to apiaries peaks. In years of food scarcity, bears can attack up to 13 times more apiaries than in years when food in the forest is abundant. These predictions can inform beekeepers when it is most urgent to effectively protect their beehives.
One of the more energetic and important foods for brown bears in temperate Europe are beechnuts – tiny little nuts that each beech tree can produce in thousands during autumn, the season when bears needs to eat huge quantities of foods to get fat before hibernation. However, beechnuts are not always available in the same amount. Beech trees in the forest seem to synchronize to produce massive quantities of beechnuts some years. But in others, the beechnut crop is completely nil and then bears have difficulties to satiate their appetite.
Bears are so reliant on beechnuts that in years when trees produce very few, they will need to look for alternative foods. A new study in the Carpathian Mountains in Poland found that in years without or with little beechnuts, the number of bear attacks to apiaries raised. “On average, the number of damages in years of little or no production of beechnuts is twice as high as the number of damages in masting years- the years with huge beechnut production”, explained Carlos Bautista, leading author of the study. “This difference can be up to 13 times high!”, he added.
This finding encouraged authors to investigate whether they could predict when beechnut production will be low, and thus, when attacks to apiaries would be higher. “The clear pattern of more damages caused to beehives in years of low production of beechnuts made us think that forecasting beechnut production was a good idea to identify years when conflicts are likely to be intense” explained Tobias Kuemmerle, co-author of the study. Using a cutting-edge combination of satellite-based measures of forest productivity, meteorological data and ground measures of beechnut production for 14 years, this study has successfully forecasted when few beechnuts and many attacks to beehives will happen. “To the best of our knowledge, this is the first study linking human-wildlife conflicts with forest productivity measured from outer space and on the ground” added Kuemmerle.
This study can help to decrease damages caused by wildlife, which are the main source of human-wildlife conflicts. “Most of the apiaries in our study area are unprotected; just very few have a proper electric fence preventing bear attacks. While it is true that in good beechnut years, protecting apiaries may be even not needed, it is clear that all apiaries should be well protected during bad beechnut years”, explained Nuria Selva, co-author of the study. “By providing this information in advance, beekeepers and wildlife agencies could really decrease economic losses and be proactive in the use of preventive measures when they are most needed”, she adds. Given the recent range expansion of large carnivores and herbivores in Europe, predicting years of natural food shortage can provide a pathway to damage prevention, and to foster coexistence between wildlife and people.
The study has just been published in Remote Sensing in Ecology and Conservation. It has been funded by Science National Centre in Poland and is the result of the collaboration between researchers from the Institute of Nature Conservation f the Polish Academy of Sciences and the Geography Department of the Humboldt University in Berlin.
Link to the paper: DOI: 10.1002/rse2.302