Can Gray wolf reappearance cause the change of territorial behaviour of Eurasian beaver?

Oldřich Vojtěch

Diplomová práce

Abstract:

The relationship between predator and prey is a dynamic process and based on a continuous evolutionary arms race. Predator develops new hunting strategies while prey tries to adapt and modify its behaviour to avoid predation. This relationship drives the population dynamics of both groups and so maintains ecological balance within the ecosystem. Predator-prey interactions stimulate adaptation and diversification of species, thereby contributing to biological diversity. This study examines the extent to which predation by the grey wolf (Canis lupus) influences the territorial behaviour of the Eurasian beaver (Castor fiber). Twenty years ago, beavers began to spread along the watercourses in the Šumava Mts., and in subsequent years, they expanded throughout the entire protected area. In 2015, the Šumava Mts. recorded the return of its apex predator–the wolf–which now occupies eight established territories. In the following seven years, beaver became part of the wolf's diet. Using telemetry technology, I collected spatial data from 11 beaver territories in the Šumava Mts. These data were then compared with spatial data from 12 beaver territories collected before the return of the wolf to the area. The results demonstrated that the recently collected data differed significantly from the data gathered before the wolf's return. Beaver territory lengths were reduced to half its original size after the wolf's return. This change in territorial behaviour is interpreted as an effort by beaver to reduce the used space, thereby shortening the distance between the periphery and the center of its territory–where dams and lodges provide protection from predators. A shorter distance between the periphery and the centre also reduces the escape distance in the event of a wolf attack - during beaver territorial marking or when foraging. During data collection, I recorded direct interactions between tagged predator individuals and telemetry-monitored prey individuals. Three out of the fifteen beavers monitored in this study became victims of wolf attacks; I also documented targeted visits by wolves to beaver territories.

Keywords

beaver, wolf, predation, territorial behaviour

Jazyk práce: angličtina

Datum vytvoření / odevzdání či podání práce: 2. 4. 2025

Obhajoba závěrečné práce

• Obhajoba proběhla 22. 5. 2025
• Vedoucí: Ing. Aleš Vorel, Ph.D.
• Oponent: Miloš Ježek, Ph.D.

Česká zemědělská univerzita v Praze

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