Tawny owl ( Strix aluco ) and its variation in diet between years

Detta är en Kandidat-uppsats från Lunds universitet/Examensarbeten i biologi

Författare: Casper Ekberg; [2021]

Nyckelord: Biology and Life Sciences;

Sammanfattning: The tawny owl resides in temperate forests in Europe and mainly hunts rodents but can also hunt other animals like birds,invertebrates and bats. In this study I examined how the diet of tawny owls varies during the span of 2018-2020, I also compared the diet found from nest boxes with footage obtained from cameras inside the nestboxes. The diet of the tawny owl can vary due to different reasons, other studies have shown that the diet is seasonal due to changes in snow cover and development of ground vegetation . Studies have also shown that different temperatures create different proportions of animals in the diet of the tawny owl. The biggest proportion of the tawny owl diet consists of mammals, more specified rodents which was shown in my study as well but the variation studied was only seen between the year 2019 and 2020. Surprising was how my result showed that birds were not the second most favoured prey item but instead a high proportion of invertebrates were found in the contents of the nestbox and no variation was found for invertebrates over the years. The lack of birds could be explained by different reasons but one is the lack of experience in identifying bones and therefore misjudging whether something is a bone of a mammal or a bird. Lastly the comparison between footage and the nest box contents showed that there was no difference in prey proportions between the two.

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