Valentin Graf, Thomas Müller, Martin U. Grüebler, Urs G. Kormann, Jörg Albrecht, Anne G. Hertel, Marjorie C. Sorensen, Matthias Tschumi, Eike Lena Neuschulz
This is a plain language summary of a Functional Ecology research article which can be found here.
Many plants rely on animals to disperse their seeds. For these plants, the behavior of the seed dispersing animal decides the fate of their seeds. However, there is little evidence on how exactly the behavior of animals affects seed fate.
In this study, we investigated the movement behavior of spotted nutcrackers (Nucifraga caryocatactes) using GPS tracking devices. These birds harvest and cache seeds of Swiss stone pine (Pinus cembra) as a food source throughout the year. While many seeds are consumed, some seeds remain unrecovered and thus have the potential to establish into pine trees. To reveal individual differences in bird behavior, we measured the distances flown by each bird per hour and exacted the locations to which seeds were transported and cached.
We found that nutcrackers showed one of two distinct behaviors: short-distance seed dispersal or long-distance seed dispersal. The seeds were either transported to high elevations with good conditions for the pine seedlings to establish (short-distance dispersal), or to lower elevations outside the pine forest and unsuitable for establishment (long-distance seed dispersal). The two behaviors were not related to bird body mass, wing length or sex.
Our results show that even among animals of the same species there is considerable variation in behavior, which has far-reaching consequences for ecological processes like seed dispersal. We emphasize that individual behavior is important and should be taken into account for a better understanding of our ecosystems.
Functional Ecology: Plain Language Summaries 